Health and Pills » Diagnosis and Therapy http://healthandpills.com Guide To Good Health and Drugs: Tablets, Gels, Capsules Tue, 07 Feb 2012 09:49:47 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Case: Muscarinic cholinomimetic agents. Questions – Answers http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents-questions-answers http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents-questions-answers#comments Tue, 15 Jun 2010 06:45:18 +0000 admin http://healthandpills.com/?p=665
Contents

      Questions

      [1] A 62-year-old woman is noted to have open-angle glaucoma. She inadvertently applies excessive pilocarpine to her eyes. This may result in which of the following?

      A. Bronchial smooth muscle dilation

      B. Decreased gastrointestinal motility

      C. Dilation of blood vessels

      D. Mydriasis

      [2] Muscarinic cholinergic agonists

      A. Activate inhibitory G-proteins (Gi)

      B. Decrease production of IP3

      C. Decrease release of intracellular calcium

      D. Inhibit the activity of phospholipase C

      [3] Choline esters like carbachol are most likely to cause which of the following adverse effects?

      A. Anhydrosis (dry skin)

      B. Delirium

      C. Salivation

      D. Tachycardia (rapid heart rate)

      Answers

      [1] C. Excessive pilocarpine may initially result in dilation of blood vessels with a drop in blood pressure and a compensatory reflex stimulation of heart rate. Higher levels will directly inhibit the heart rate. In addition, pilocarpine stimulation of muscarinic cholinoreceptors can result in miosis, bronchial smooth muscle dilation, and increased GI motility.

      [2] A. In addition to activating inhibitory G-proteins (Gi), muscarinic cholinergic agonists stimulate the activity of phospholipase C, increase production of IP3, and increase release of intracellular calcium.

      [3] C. Diarrhea, salivation, and lacrimation may be seen. The heart rate is usually slowed. Choline esters do not cross the blood-brain barrier, and therefore delirium is not an adverse effect.

      Pharmacology pearls

      Cholinoreceptors are classified as either nicotinic or muscarinic.

      Muscarinic cholinoreceptors are localized at organs such as the heart, causing a negative chronotropic effect.

      Stimulation of muscarinic receptors in the smooth muscle, exocrine glands, and vascular endothelium cause bronchoconstriction, increased acid secretion, and vasodilation.

      Methacholine and bethanechol are highly selective for muscarinic cholinoreceptors.

      Cholinomimetic agents, including anticholinesterase inhibitors, are precluded for treatment of gastrointestinal or urinary tract disease because of mechanical obstruction, where therapy can result in increased pressure and possible perforation. They are also not indicated for patients with asthma.

      ]]> http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents-questions-answers/feed 0 Case: Muscarinic cholinomimetic agents. Class http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents-class http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents-class#comments Mon, 14 Jun 2010 06:42:24 +0000 admin http://healthandpills.com/?p=659
      Contents

          The efferent nerves of the parasympathetic autonomic nervous system release the neurotransmitter ACh at both preganglionic and postganglionic (i.e., “cholinergic”) nerve endings, and also at somatic nerve endings. Nitric oxide is a cotransmitter at many of the parasympathetic postganglionic sites.

          The ACh released from nerve endings of the parasympathetic nervous system interacts at specialized cell membrane components called cholinoreceptors that are classified as either nicotinic or muscarinic after the alkaloids initially used to distinguish them.

          Nicotinic cholinoreceptors are localized at all postganglionic neurons (the autonomic ganglia), including the adrenal medulla, and skeletal muscle endplates innervated by somatic nerves. Muscarinic cholinoreceptors are localized at organs innervated by parasympathetic postganglionic nerve endings, for example, on cardiac atrial muscle, sinoatrial node cells, and atrioventricular node cells, where activation can cause a negative chronotropic effect and delayed atrioventricular conduction. Cholinergic stimulation of muscarinic receptors in the smooth muscle, exocrine glands, and vascular endothelium can cause, respectively, bronchoconstriction, increased acid secretion, and vasodilation (Table:Effects of cholinoreceptor activation).

          Table: Effects of cholinoreceptor activation

          Organ Effects
          Bronchial smooth muscle Contracts
          Heart rate Decreases
          Eye smooth muscles
          Pupil size
          Accommodation          		 Contracts
          Contracts
          Blood vessels Dilate*
          Gastrointestinal tract (tone, motility, secretions) Increase

          * There is no parasympathetic innervation of blood vessels. However, they have cholinoreceptors that when activated result in their dilation.

          There are two subtypes of the nicotinic cholinoreceptors: NN, localized to postganglionic neurons, and NM, localized to the skeletal muscle endplates. There are three pharmacologically important subtypes of the muscarinic cholinoreceptors, M1, M2, and M3 (two additional subtypes have been identified by cloning), that alone or in combination are localized to sympathetic postganglionic neurons (and the CNS), to the atrial muscle, sinoatrial (SA) cells, and atrioventricular (AV) node of the heart, to smooth muscle, to exocrine glands, and to the vascular endothelium that does not receive parasympathetic innervation.

          Directly and indirectly acting parasympathetic cholinomimetic agents, primarily pilocarpine and bethanechol, and neostigmine, are used most often therapeutically to treat certain diseases of the eye (acute angle-closure glaucoma), the urinary tract (urinary tract retention), the gastrointestinal tract (postoperative ileus), salivary glands (xerostomia), and the neuromuscular junction (myasthenia gravis). The ACh is generally not used clinically because of its numerous actions and very rapid hydrolysis by AChE and pseudocholinesterase.

          The adverse effects of direct- and indirect-acting cholinomimetics result from cholinergic excess and may include diarrhea, salivation, sweating, bronchial constriction, vasodilation, and bradycardia. Nausea and vomiting are also common. Adverse effects of cholinesterase inhibitors (most often as a result of toxicity from pesticide exposure, e.g., organophosphates) also may include muscle weakness, convulsions, and respiratory failure.

          Structure

          ACh is a choline ester that is not very lipid soluble because of its charged quaternary ammonium group. It interacts with both muscarinic and nicotinic cholinoreceptors. Choline esters similar in structure to ACh that are used therapeutically include methacholine, carbachol, and bethanechol. Unlike ACh and carbachol, methacholine and bethanechol are highly selective for muscarinic cholinoreceptors. Pilocarpine is a tertiary amine alkaloid.

          Mechanism of Action

          Muscarinic cholinoreceptors activate inhibitory G-proteins (Gi) to stimulate the activity of phospholipase C, which, through increased phospholipid metabolism, results in production of inositol triphosphate (IP3) and DAG that lead to the mobilization, respectively, of intracellular calcium from the endoplasmic and sarcoplasmic reticulum and, through activation of protein kinase C (PK-C), the opening of smooth muscle calcium channels with an influx of extracellular calcium. Activation of muscarinic cholinoreceptors also results in altered potassium flux that results in cell hyperpolarization, and in inhibition of adenylyl cyclase activity and cAMP accumulation induced by other hormones, including the catecholamines.

          The nicotinic receptor functions as a cell membrane ligand-gated ion channel pore. On interaction with ACh, the receptor undergoes a conformational change that results in influx of sodium with membrane depolarization of the nerve cell or the skeletal muscle neuromuscular endplate.

          Indirectly acting parasympathetic cholinomimetic agents inhibit AChE and thereby increase ACh levels at both muscarinic and nicotinic cholinoreceptors.

          Administration

          Directly acting muscarinic cholinomimetic agents may be administered topically as ophthalmic preparations (pilocarpine, carbachol), orally (bethanechol, pilocarpine), or parenterally (bethanechol). Depending on the agent, an indirectly acting cholinesterase inhibitor may be administered topically, orally, or parenterally.

          Pharmacokinetics

          ACh is synthesized from choline and acetyl-coenzyme A (acetyl-CoA) by the enzyme choline acetyltransferase and then transported into nerve ending vesicles. Like ACh, methacholine, carbachol, and bethanechol are poorly absorbed by the oral route and have limited penetration into the CNS. Pilocarpine is more lipid soluble and can be absorbed and can penetrate the CNS.

          After release from nerve endings, ACh is rapidly metabolized into choline and acetate, and its effects are terminated by the action of the enzymes AChE and pseudocholinesterase. Methacholine and particularly carbachol and bethanechol are resistant to the action of cholinesterases.

          Continuation: Case: Muscarinic cholinomimetic agents. Questions – Answers

          ]]> http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents-class/feed 0 Case: Muscarinic cholinomimetic agents http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents#comments Sun, 13 Jun 2010 06:33:02 +0000 admin http://healthandpills.com/?p=657
          Contents

              A 61-year-old man is noted to have increased intraocular pressure on a routine eye examination. The visual acuity is normal in both eyes. The dilated eye examination reveals no evidence of optic nerve damage. Visual field testing shows mild loss of peripheral vision. He is diagnosed with primary open-angle glaucoma and is started on pilocarpine ophthalmic drops.

              What is the action of pilocarpine on the muscles of the iris and cilia?

              What receptor mediates this action?

              Is pilocarpine the appropriate first-line drug for treatment of primary open-angle glaucoma?

              Answers to case: Muscarinic cholinomimetic agents

              Summary: A 61-year-old man with open-angle glaucoma is prescribed pilo-carpine ophthalmic drops.

              Action of pilocarpine on muscles of the iris and cilia: Constriction of the muscles

              Receptor that mediates this action: Muscarinic cholinoreceptor

              First-line drugs to treat primary open-angle glaucoma: Prostaglandin analogs

              Clinical correlation

              Open-angle glaucoma is a disease caused by obstruction of the outflow of aqueous humor into the canal of Schlemm, causing an increase in intraocular pressure. The use of a direct-acting muscarinic agonist, such as pilocarpine, causes contraction of the muscles of the cilia and iris. Because these are circular muscles, the pupil is constricted, which helps to relieve the outflow obstruction and lower the intraocular pressure. Although not common with the use of topical ophthalmic drops, bronchospasm and pulmonary edema has been noted with the use of pilocarpine drops. More commonly, blurred vision and myopia (nearsightedness) occur as a result of the impairment of accommodation caused by the contraction of the iris and ciliary muscles.

              The use of a direct-acting muscarinic agonist such as pilocarpine to treat open-angle glaucoma is now not common due to its numerous side effects, the need to administer it up to four times per day, and the availability of other agents. Prostaglandin analogs such as latanoprost are now considered first-line therapy for this condition followed by β-adrenoceptor agonists.

              Approach to muscarinic cholinomimetic agents

              Objectives

              1. Be able to list the receptors of the parasympathetic nervous system.

              2. Contrast the actions and effects of direct and indirect stimulation of muscarinic cholinoreceptors.

              3. List the therapeutic uses of parasympathomimetic agents.

              4. List the adverse effects of parasympathomimetic agents.

              Definitions

              Parasympathetic nervous system: An anatomic division of the autonomic nervous system (the other is the sympathetic nervous system) that originates in nuclei of the CNS. Preganglionic fibers exit through cranial and sacral spinal nerves to synapse via short postganglionic nerve fibers on ganglia, many of which are in the organs they innervate.

              Cholinomimetic agents: Agents that mimic the action of ACh. These act directly or indirectly to activate cholinoreceptors. Some directly acting agents (pilocarpine, bethanechol, carbachol) are designed to act selectively on either muscarinic or nicotinic cholinoreceptors, whereas indirectly acting agents (such as neostigmine, physostigmine, edrophonium, demecarium), which inhibit the enzyme acetylcholinesterase (AChE) that is responsible for the inactivation of ACh, can activate both. Pilocarpine is a directly acting cholinomimetic agent that acts chiefly at muscarinic cholinoreceptors. Additional selectivity of pilocarpine and other cholinomimetics in the treatment of glaucoma is achieved by the use of an ophthalmic (topical) preparation.

              Continuation: Case: Muscarinic cholinomimetic agents. Class

              ]]> http://healthandpills.com/diagnosis-and-therapy/case-muscarinic-cholinomimetic-agents/feed 0 Drugs of abuse. Class http://healthandpills.com/diagnosis-and-therapy/drugs-of-abuse-class http://healthandpills.com/diagnosis-and-therapy/drugs-of-abuse-class#comments Thu, 03 Jun 2010 04:09:44 +0000 admin http://healthandpills.com/?p=651
              Contents

                  In addition to alcohol, the major drugs of abuse are nicotine, marijuana (∆9-tetrahydrocannabinol), heroin, and the CNS stimulants, notably cocaine and amphetamine and its derivatives (Table Drugs of abuse).

                  Table: Drugs of abuse

                  NICOTINE MARIJUANA COCAINE/AMPHETAMINE
                  Route of administration Smoking Smoking Smoking, oral IV
                  Mechanism of action Mimics action of acetylcholine Interacts with G-protein-coupled cannabinoid receptors among other actions Cocaine binds the dopamine reuptake transporter. Amphetamine increases release of neuronal catecholamines, including dopamine
                  Pharmacologic effects Stimulant and depressant actions on the CNS and cardiovascular system Euphoria, uncontrollable laughter, introspection, loss of sense of time, sleepiness, loss of concentration Euphoria, excitation, increased alertness, an orgasmic-like “rush”
                  Tolerance and dependence Tolerance develops rapidly Strong psychologic dependence Withdrawal syndrome indicative of physical dependence Arguably, some tolerance and very mild physical dependence Rapid development of tolerance. Withdrawal syndrome characterized by increased appetite, depression, and exhaustion
                  Therapeutic uses None Nausea and vomiting of cancer. Appetite stimulation in AIDS (dronabinol) Local anesthesia (cocaine). ADHD (methylphenidate). Narcolepsy (modafmil)
                  Adverse effects Cancer, obstructive lung disease, cardiovascular disease Bronchitis, increased pulse rate, reddening of conjunctiva Paranoid schizophrenia. Amphetamine-specific necrotizing arteritis. Cocaine-related arrhythmias, seizures, respiratory depression, hypertension, stroke, increased fetal mortality, and abnormalities
                  Treatment of abuse Nicotine gum and transdermal patch Behavioral modification Antipsychotic agents. Antidepressant agents

                  Questions

                  [1] Alcohol is oxidized by which of the following enzymes?

                  A. Acetate oxidase

                  B. ADH

                  C. Aldehyde dehydrogenase

                  D. Monoamine oxidase

                  [2] Which of the following is the most common adverse effect resulting from chronic ethanol abuse?

                  A. Cirrhosis

                  B. Cutaneous vasodilation

                  C. Disinhibited j udgment

                  D. Respiratory depression

                  [3] Which of the following is a drug of abuse that blocks the dopamine uptake transporter?

                  A. Alcohol

                  B. Cocaine

                  C. Marijuana

                  D. Nicotine

                  Answers

                  [1] B. Alcohol is oxidized in the liver, stomach, and other organs to acetaldehyde by the cytosolic enzyme ADH and the hepatic microso-mal enzymes. Acetaldehyde is oxidized to acetate by mitochondrial hepatic aldehyde dehydrogenase.

                  [2] A. Liver cirrhosis is an effect of chronic alcohol use. Disinhibited judgment, respiratory depression, and cutaneous vasodilation are acute effects of alcohol.

                  [3] B. Cocaine is a drug of abuse that binds the dopamine reuptake transporter. Ethanol may nonspecifically disrupt cell membrane protein functions. Marijuana interacts with G-protein-coupled cannabinoid receptors. Nicotine mimics the action of acetylcholine.

                  Pharmacology pearls

                  Alcohol is the most widely used drug of abuse.

                  Delirium Tremens, a syndrome associated with the abrupt discontinuation of alcohol in a chronic abuser, carries a high mortality rate if not promptly identified and treated.

                  Withdrawal from other drugs of abuse may cause unpleasant symptoms for the patient, but is rarely life threatening.

                  In all hypotheses of addiction, increased concentrations of dopamine in the mesolimbic system is considered the neurochemical correlate of dependence and addiction.

                  ]]> http://healthandpills.com/diagnosis-and-therapy/drugs-of-abuse-class/feed 0 Drugs of abuse http://healthandpills.com/diagnosis-and-therapy/case-drugs-of-abuse http://healthandpills.com/diagnosis-and-therapy/case-drugs-of-abuse#comments Wed, 02 Jun 2010 04:09:37 +0000 admin http://healthandpills.com/?p=648
                  Contents

                      A 50-year-old salesman was admitted to the hospital with acute appendicitis. He has no significant medical history, takes no medications, does not smoke cigarettes, and has an alcoholic beverage “once in a while with the boys.” He underwent an uncomplicated appendectomy. On the second hospital day, you find him to be quite agitated and sweaty. His temperature, heart rate, and blood pressure are elevated. A short time later he has a grand-mal seizure. You suspect that he is having withdrawal symptoms from chronic alcohol abuse and give IV lorazepam for immediate control of the seizures and plan to start him on oral chlordiazepoxide when he is more stable.

                      What are the acute pharmacologic effects of ethanol?

                      What are the chronic pharmacologic effects of ethanol?

                      How is alcohol metabolized?

                      What is the pharmacologic basis for using benzodiazepines to manage alcohol withdrawal?

                      Answers to case: Drugs of abuse

                      Summary: A 50-year-old man is displaying symptoms and signs of acute alcohol withdrawal.

                      Symptoms of acute ethanol toxicity: Disinhibited behavior and judgment, slurred speech, impaired motor function, depressed and impaired mental function, respiratory depression, cutaneous vasodilation, diuresis, gastrointestinal side effects, and impaired myocardial contractility.

                      Symptoms of chronic ethanol toxicity: Alcoholic fatty liver, alcoholic hepatitis, cirrhosis, liver failure, peripheral neuropathy, alcohol amnesic syndrome, pancreatitis, gastritis, fetal alcohol syndrome, nutritional deficiencies, cardiomyopathy, cerebellar degeneration.

                      Metabolism of alcohol: Oxidized primarily in the liver but also in the stomach and other organs to acetaldehyde by the cytosolic enzyme alcohol dehydrogenase (ADH) and by hepatic microsomal enzymes; acetaldehyde is oxidized to acetate by hepatic mitochondrial aldehyde dehydrogenase.

                      Benzodiazepines in alcohol withdrawal: Both alcohol and the benzodiazepines enhance the effect of y-aminobutyric acid (GABA) on GABAA neuroreceptors, resulting in decreased overall brain excitability. This cross-reactivity explains why relatively long-acting benzodiazepines (e.g., lorazepam, chlordiazepoxide) can be substituted for alcohol in a detoxification program.

                      Clinical correlation

                      Ethanol is the most widely used CNS depressant. It is rapidly absorbed from the stomach and small intestine and distributed in total body water. Its exact mechanism of action is not known, but may be related to its generally disruptive effects on cell membrane protein functions throughout the body, including effects on signaling pathways in the CNS. At low doses it is oxidized by cytoplasmic ADH. At higher doses it is also oxidized by liver microsomal enzymes, which may be induced by chronic use. These enzymes are rapidly saturated by the concentrations of alcohol achieved by even one or two alcoholic drinks so that its rate of metabolism becomes independent of plasma concentration. Tolerance to the intoxicating effects of alcohol can develop with chronic use. Cross-tolerance with barbiturates and benzodiazepines may also develop. Because of this cross-tolerance effect, benzodiazepines are the most commonly used agents for the treatment of alcohol withdrawal, a potentially life-threatening syndrome commonly seen 2-3 days after the abrupt cessation of alcohol use by a chronic abuser. A long-acting benzodiazepine can be taken, and gradually tapered, to mitigate this effect. Disulfiram is also used on occasion to manage alcoholism. It is a drug that inhibits aldehyde dehydrogenase that in the presence of alcohol causes an accumulation of acetaldehyde, which results in a highly aversive reaction consisting of flushing, severe headache, nausea and vomiting, and confusion. Naltrexone, an opioid antagonist, is yet another drug used to manage alcoholism.

                      Approach to pharmacology of ethanol

                      Objectives

                      1. Define drug abuse, drug tolerance, drug dependence, and drug addiction.

                      2. List the common drugs of abuse and their properties.

                      3. List the adverse effects of the common drugs of abuse.

                      Definitions

                      Drug abuse: Nonmedical use of a drug taken to alter consciousness or to change body image that is often regarded as unacceptable by society. Not to be confused with drug misuse.

                      Drug tolerance: Decreased response to a drug with its continued administration that can be overcome by increasing the dose. A cellular tolerance develops to certain drugs of abuse that act on the CNS because of a poorly understood biochemical or homeostatic adaptation of neurons to the continued presence of the drug. Also, in addition to a cellular tolerance, a metabolic tolerance can develop to the effects of some drugs because they increase the synthesis of enzymes responsible for their own metabolism (alcohol, barbiturates).

                      Drug dependence: Continued need of the user to take a drug. Psychologic dependence is the compulsive behavior of a user to continue to use a drug no matter the personal or medical consequences. Inability to obtain the drug activates a “craving” that is very discomforting. Physical or physiologic dependence is a consequence of drug abstinence after chronic drug use that results in a constellation of signs and symptoms that are often opposite to the initial effects of the drug and to those sought by the user. Psychologic dependence generally precedes physical dependence but, depending on the drug, does not necessarily lead to it. The development of physical dependence, the degree of which varies considerably for different drugs of abuse, is always associated with the development of tolerance, although the exact relationship is unclear.

                      Drug addiction: A poorly defined, imprecise term with little clinical significance that indicates the presence of psychologic and physical dependence.

                      Continuation: Drugs of abuse. Class

                      ]]> http://healthandpills.com/diagnosis-and-therapy/case-drugs-of-abuse/feed 0 Managing Pain in the Older Patient Part 4 http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-4 http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-4#comments Sat, 31 Oct 2009 03:25:45 +0000 admin http://healthandpills.com/?p=320
                      Contents

                          Challenges in Medicating the Senior Patient

                          Choosing an appropriate dosage form of analgesic drug is essential to successfully manage pain in the older patient. Beyond the clinical recommendations, the pharmacist can be instrumental in providing information on products that will optimize pain relief in this patient population. Swallowing difficulties secondary to other medical conditions, such as Parkinson’s disease, dementia, or stroke, may preclude the use of large tablets or sustained-release medications that cannot be crushed. Liquid medications provide an acceptable alternative for administering analgesics. Unfortunately, few analgesic preparations are available in liquid form. Ibuprofen and naproxen suspensions are the few NSAIDs available as liquids for the relief of mild to moderate pain. For moderate to severe pain, fentanyl patches provide continuous pain relief and are suitable for patients who cannot swallow sustained-release preparations, are tube-fed, or who have difficulty remembering to take their medication. The 72-hour administration interval also reduces the burden of administering medication by nursing staff in long-term care facilities or caregivers at home. The initial dose of the patch may be increased after the first three days of therapy. Additional dose increases should only occur after two cycles of patches have been applied. Morphine sulfate controlled-release capsules may be opened and the pellets mixed in applesauce or administered via a gastrostomy tube without loss of continuous pain relief. Patient controlled analgesia (PCA) through the use of a pump has not been as widely used in elderly patients, particularly those with cognitive impairment, since successful use requires active involvement by the patient.

                           
                          Analgesics that are considered unnecessary drugs with a high potential for significant adverse effects and should be avoided include pentazocine and oral meperidine.

                          The older patient may be taking numerous medications, some of which may induce similar side effects as pain management therapy. Constipation is frequently a side effect of narcotic analgesic administration, particularly as the dose increases, placing the patient at risk for fecal impaction. Patients may also be taking calcium supplements and psychoactive agents, which can contribute to constipation. A review of bowel management therapy is advised at the time of prescribing narcotics.

                          According to the World Health Organization guidelines, the basis for current pain management practices, senna is the laxative of choice for managing opiate-induced constipation. Normal peristaltic movement is inhibited by opiates, preventing movement of fecal material through the colon. Irritant laxatives, such as senna, can help stimulate bowel evacuation. Docusate or psyllium-containing products may be of additional benefit to prevent straining or to add bulk. Adequate fluid intake is essential to prevent possible bowel obstruction associated with the use of bulk-forming laxatives.

                          Health Care Financing Administration (HCFA) Interpretive Guidelines also influence the process of selecting drug therapy for pain management. The use of tricyclic antidepressants, especially amitriptyline and doxepin, is discouraged in elderly patients due to their increased sensitivity to adverse effects, particularly anticholinergic effects and heart rhythm abnormalities. If a tricyclic agent is to be used, particularly for neuropathic pain, nortriptyline is preferred at low doses with careful titration and monitoring. Patients currently receiving amitriptyline should be considered for conversion to nortriptyline in equipotent doses. Documentation of efficacy and absence of adverse effects should be readily available. During medication pass and meal observation, surveyors are instructed to determine whether NSAIDs are administered with a meal. If they are administered on an empty stomach, it is calculated into the facility’s medication error rate.

                          Analgesics that are considered unnecessary drugs with a high potential for significant adverse effects and should be avoided include pentazocine and oral meperidine. Both drugs have an increased risk of respiratory depression or central nervous system adverse effects, including seizures with meperidine, in patients over 65 years of age. Alternative agents with less serious adverse effects are readily available.

                          Conclusion

                          Successful chronic pain management in the senior patient requires the active involvement of the pharmacist in the community as well as the institution. Regulatory requirements have established a framework for a comprehensive approach to pain management and a fundamental right of patients to adequate relief of pain. Overcoming the barriers to adequate pain relief is only one of the challenges facing the patient and the clinician. Multiple opportunities exist for enhancing patient quality of life. The pharmacist can help educate patients, families and staff about pain management, provide the clinical expertise necessary to manage pain, recommend dosage forms and adjunct medications that will enhance therapy, and measure outcomes of pain management programs.

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                          Contents

                              Drugs Used in Pain Management

                              Pharmacologic options for pain management range from simple analgesics, such as acetaminophen or low-dose nonsteroidal anti-inflammatory agents (NSAIDs) for the relief of mild to moderate chronic pain, to opioids for more severe pain (Table 1).

                              Simple Analgesics: Acetaminophen is useful for the relief of mild to moderate osteoarthritic pain in scheduled, divided doses not exceeding 4 g/day.NSAIDs may also be used in appropriate doses, for short periods of time. COX-2 inhibitors may be less likely to be associated with gastrointestinal bleeding and may be administered once daily, reducing nursing time for medication administration or the likelihood of missed doses. All NSAIDs should be given with a meal to avoid gastrointestinal upset. Periodic monitoring of renal function and blood count should be performed.

                              Topical Analgesics: Topical analgesics may also be used in the management of chronic pain. Capsaicin cream, derived from red peppers, desensitizes nerve fibers associated with pain by depleting substance P. Regular applications of the cream, beginning with the 0.025% concentration and progressing to the 0.075% formulation, may be helpful in relieving pain. Patients generally report a warming sensation at the site of application. The cream should not be used on broken or irritated skin. Several weeks of therapy may be necessary to determine efficacy. Menthol or methylsalicylate-containing products in the form of liniments, creams, sprays and other formulations may also be effective in relieving joint pain. Topical anesthetics, such as lidocaine ointment or gel, and combination anesthetic ointments or creams may also be of benefit in relieving joint pain or pain in other localized sites.

                              Table 1
                              Pharmacologic Management of Pain

                              Analgesics

                              Acetaminophen
                              Nonsteroidal anti-inflammatory agents
                              Nonselective
                              COX-2 inhibitors

                              Topical analgesics/anesthetics

                              Capsicum/Lidocaine

                              Tramadol

                              Antidepressants

                              Tricyclics SSRIs

                              Anticonvulsants

                              Gabapentin
                              Carbamazepine

                              Narcotic analgesics

                              Adjunct medications

                              Clonidine patches

                              Corticosteroids

                              Tramadol: Tramadol has been successful in managing pain in patients over the age of 75 years who are unable or unwilling to use opioids at doses of 300 mg or less per day. Doses in renally impaired patients (those with a creatinine clearance [CrCl] of 30 mL/min or less) should be further reduced by decreasing the dosing interval to every 12 hours and a maximum dosage of 200 mg/day. Dosage adjustment is also necessary in patients with hepatic impairment. Tramadol should not be used with opioids, tricyclic anti-depressants, or selective serotonin reuptake inhibitors. Patients taking other medications that lower the seizure threshold or who are at high risk for seizures may experience seizures with the addition of tramadol. Concomitant use of carbamazepine significantly lowers the bioavailability of tramadol, requiring a dose increase. In clinical studies with a majority of patients over the age of 65 years, dizziness, nausea, and vertigo were the most common side effects, reported in up to 46% of patients receiving tramadol for as long as three months.

                              Tricyclic Antidepressants: Tricyclic antidepressants have been successfully used in managing pain in combination with analgesic agents, particularly for neuropathic pain syndromes. Initiation of therapy at low doses (10­25 mg of nortriptyline) given at bedtime will avoid daytime drowsiness and improve sleep. Limited data exist for the efficacy of the selective serotonin reuptake inhibitors as adjunct pain management, precluding their routine substitution for tricyclic agents.

                              Anticonvulsants: With relatively few drug interactions in comparison to other anticonvulsants, gabapentin has been shown to be effective as adjunct pain therapy in patients with neuropathic pain. Gabapentin was shown to be as effective as amitriptyline in the management of diabetic peripheral neuropathy. In order to avoid the most common side effect, drowsiness, therapy is initiated at relatively small doses of 100 mg in the evening, with gradual upward titration every five to seven days. In patients with impaired renal function (CrCl>60 mL/min), doses should not exceed 1200 mg/day in divided doses.A maximum dose of 600 mg/day in divided doses is recommended in patients with CrCl 30­60 mL/min. Monitoring of drug serum levels is not indicated with gabapentin.

                              Narcotic Analgesics: Multiple narcotic analgesics are available as single agents or in combination with other analgesics for the relief of moderate to severe pain. Sustained-release preparations, such as morphine sulfate sustained-release tablets, offer the benefit of once or twice a day administration with continuous pain relief. Short-acting, immediate release formulations should be readily available to the patient for breakthrough episodes of pain. Use of the short-acting agents serves as a method of titration for the sustained-release preparations and as a measure of their efficacy. The timing of the use of immediate-release medications on a prn basis can help determine if pain control is diminished at the end of the dosing interval or if specific times of the day require an increased dose of analgesic. The inclusion of acetamin-ophen or ibuprofen with narcotic analgesics limits their usefulness. Acetaminophen-associated hepatotoxicity and ibuprofen-associated renal and gastrointestinal toxicities limit the total daily dose of the combination products. With gradual dose titration based on patient response, there is no dose limitation with single-agent narcotic analgesics. Oxycodone controlled-release tablets or other narcotic analgesics may be alternatives in patients unable to tolerate morphine sulfate, as intolerance of one agent does not prevent the trial of other narcotic analgesics.

                              Nonpharmacologic Interventions: Nonpharmacologic interventions have been used, often in conjunction with analgesic or adjunct medications, as part of a comprehensive pain management program (Table 2). Specific modalities may be used alone or in combination, depending on the patient’s condition.

                              As part of an interdisciplinary team, the pharmacist should ascertain whether all of the patient’s pain needs are being met during or after physical therapy sessions. Patients may refuse therapy sessions because they perceive the sessions as causing pain, or pain exists prior to the therapy visit. Premedication with a relatively rapid onset analgesic one-half to one hour prior to the therapy appointment can significantly reduce discomfort and allow the rehabilitation process to proceed smoothly. Medication after the therapy session can be useful in relieving discomfort or aching experienced by the patient.

                              Patients may also experience pain during wound care. Routine premedication for dressing changes in patients with a Stage III or IV pressure ulcer or other serious wound is recommended and can reduce the discomfort or pain associated with manipulation of the affected area.

                              Table 2
                              Nonpharmacologic Treatment of Pain div>
                              • Acupuncture
                              • Exercise
                              • Guided imagery
                              • Ice or heat packs
                              • Occupational or physical therapy
                              • Pastoral or psychological support
                              • Transcutaneous electrical nerve stimulation (TENS)

                              ]]> http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-3/feed 0 Managing Pain in the Older Patient Part 2 http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-2 http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-2#comments Sat, 31 Oct 2009 03:23:27 +0000 admin http://healthandpills.com/?p=314
                              Contents

                                  Managing Pain

                                   

                                  Clinical assessment of elderly patients must attempt to ascertain the presence of pain through both verbalized and nonverbalized symptoms.

                                  Selecting an optimal therapy depends on patient-specific criteria, including medical history, previous medications utilized, drug allergies, swallowing ability, and response to therapy. A description of the pain is also useful in determining initial therapy. Nociceptive pain, often the result of chronic or other conditions arising from actual tissue damage as in osteoarthritis, can be described as aching or soreness, rather than sharp pain. Neuropathic pain, arising from damaged nerve tissue, is usually described as burning, stinging or stabbing pain. To adequately manage chronic pain, the clinician should employ a step-therapy approach that uses regularly scheduled doses of medication rather than dependence on a regimen of “prn” doses. This avoids underdosing and its resulting inadequate pain relief. Titrating the dose and managing occasional variations in pain patterns are achieved through the use of rescue analgesics. Adjunct medications and nonpharmacologic interventions enhance the efficacy of analgesics; both are useful in managing chronic neuropathic and nociceptive pain. Adjunct medications may also have a positive effect on accompanying symptoms, including insomnia and depression. Therapy should be initiated in low doses, with gradual upward titration until pain relief is achieved.

                                  Adequate pain management is a cornerstone of both palliative care and hospice care. Palliative care, the active care of a patient whose disease is not responsive to curative treatment, may be long-term. In contrast, a patient who is receiving hospice care has a life expectancy of six months or less. Regardless of the category of care the patient is receiving, appropriate management of pain and other associated symptoms is essential to the patient’s well-being and quality of life.

                                  ]]> http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-2/feed 0 Managing Pain in the Older Patient Part 1 http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-1 http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-1#comments Sat, 31 Oct 2009 03:21:09 +0000 admin http://healthandpills.com/?p=308
                                  Contents

                                      Older patients have a variety of chronic illnesses that may result in pain. However, the daily presence of pain often goes unrecognized and, therefore, untreated in both the community-dwelling and institutionalized elderly. Chronic pain may be the result of comorbidities, including osteoarthritis, osteoporosis, cancer, peripheral vascular disease, or neuropathies secondary to complications of diabetes. Procedures such as surgery, open wounds and pressure ulcers can also be a source of pain. Identifying and adequately managing pain in the elderly patient presents unique challenges for the pharmacist and the entire healthcare team.

                                      The lack of recognition and consequent undertreatment of pain in all patient populations has resulted in new standards from the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) for all levels of care. Organizations seeking JCAHO accreditation or reaccreditation must have a comprehensive pain management program in place. Underlying the new standards is a commitment to every patient’s right to adequate treatment of pain. This is accomplished through the organization’s program of education for all staff, patients, residents, and families; development and use of appropriate tools for pain assessment; care of persons with pain; inclusion of pain management in discharge planning; and incorporating pain management into the institution’s performance improvement program. The pharmacist is considered an essential staff member for a successful pain management program, not only in the educational component, but also in the development of policies and procedures, drug therapy protocols, and outcomes assessment.

                                      New JCAHO standards commit to every patient’s right to adequate treatment of pain.

                                      To emphasize the importance of routine and ongoing pain assessment, the American Pain Society (APS) has labeled pain as “the fifth vital sign.” Consistent with the JCAHO standards, which the Society endorsed, the APS seeks to provide practical measures in order to make adequate pain management a reality for every patient.

                                      Assessment and Identification of Pain

                                      Clinical assessment of all elderly patients must attempt to ascertain the presence of pain through both verbalized and nonverbalized symptoms. An elderly patient may verbally respond to questions about the presence of pain by stating that he has no pain but may, in fact, be experiencing unrelieved or inadequately relieved pain. In addition to an inability to express the presence of pain due to progressing dementia, aphasia, or language barriers, there may be cultural or societal barriers to articulating pain symptoms. Cultural beliefs that pain is a sign of weakness and that suffering is preferable to accepting pain medication may precondition the patient to deny the presence of pain. The patient, his or her family, and health professionals may have the misconception that narcotic analgesics should not be used because of the potential for physical dependence. Healthcare staff may not be adequately trained in recognizing the signs of pain in the older patient or in assessing pain relief. Staff cultural beliefs about patient perception of pain and treatment may hinder adequate pain management as well.

                                      Pain scales that can be used to assess the intensity of verbally expressed pain include numeric or descriptive scales. The Wong Baker Faces Scale may be especially useful when verbal description is not possible. The patient may be able to indicate which face best demonstrates how he or she feels; if not, staff can match the face to the patient in front of them. Nonverbal cues may indicate the presence of pain in the elderly patient who denies or is unable to indicate the presence of pain. In addition to facial expression, behaviors that can indicate actual unrelieved pain include agitated behavior, pulling away or refusing care, favoring or rubbing a limb or body part, gait disturbances, declining to participate in rehabilitation activities, withdrawing from social activities, loss of appetite with resulting weight loss, insomnia, or symptoms of depression.

                                      ]]> http://healthandpills.com/diagnosis-and-therapy/pain-management/managing-pain-in-the-older-patient-part-1/feed 0 Psychotherapy Alone May Help Some Depression Patients http://healthandpills.com/diagnosis-and-therapy/psychotherapy-alone-may-help-some-depression-patients http://healthandpills.com/diagnosis-and-therapy/psychotherapy-alone-may-help-some-depression-patients#comments Tue, 27 Oct 2009 06:02:07 +0000 admin http://healthandpills.com/?p=109 A recent study concludes that cognitive psychotherapy can be just as effective for the treatment of atypical major depression as standard drug therapy with phenelzine sulfate. Researchers at the University of Texas-Southwestern Medical Center at Dallas randomized 108 patients suffering from atypical major depression to treat with the MAO inhibitor phenelzine sulfate, cognitive therapy, or placebo for 10 weeks to collect data. The study found that 58 percent of patients in both the cognitive therapy and phenelzine sulfate groups responded to treatment, compared to 28 percent of placebo recipients. Authors say the findings suggest that cognitive therapy is an effective and viable alternative to drug therapy for atypical major depression.

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