B3 AccessMed Flashcards
Characteristics of phase I depolarizing neuromuscular blockade due to succinylcholine include
Ans:Sustained tension during a period of tetanic stimulation
Phase I depolarizing blockade caused by succinylcholine is not associated with antagonism at muscarinic receptors, nor is it reversible with cholinesterase inhibitors. Muscle fasciculations occur at the start of the action of succinylcholine.
Which statement concerning the adverse effects of antipsychotic drugs is accurate?
Ans:Acute dystonic reactions occur very infrequently with olanzapine
Olanzapine has minimal dopamine receptor-blocking action and is unlikely to cause acute dystonias. Muscarinic blockers such as atropine exacerbate tardive dyskinesias. Akathisias (uncontrollable restlessness) resulting from antipsychotic drugs may be relieved by a reduction in dosage. Retinal pigmentation may occur with thioridazine, not clozapine.
Concerning hypotheses for the pathophysiologic basis of schizophrenia, which statement is accurate?
Ans: Drug-induced psychosis can occur without activation of brain dopamine receptors
Although most older antipsychotic drugs block D2 receptors, this action is not a requirement for antipsychotic action. Aripiprazole, clozapine, and most newer second-generation drugs have a very low affinity for such receptors, but a high affinity for serotonin 5-HT2 receptors. There are no reports of changed levels of serotonin in the brains of schizophrenics. The CNS effects of phencyclidine (PCP) closely parallel an acute schizophrenic episode, but PCP has no actions on brain dopamine receptors. Dopamine receptor blockers cause extrapyramidal dysfunction.
Concerning the proposed mechanisms of action of antidepressant drugs, which statement is accurate?
Ans: Nefazodone blocks 5-HT receptors in the CNS
The mechanism of action of bupropion is unknown, but the drug does not inhibit either NE or 5-HT transporters. Levels of NE and 5-HT metabolites in the cerebrospinal fluid of depressed patients before drug treatment are not higher than normal. Downregulation of adrenoceptors appears to be a common feature of chronic treatment of depression with tricyclic drugs such as amitriptyline. Selegiline is a selective inhibitor of MAO-B, the enzyme form that metabolizes dopamine (see Chapter 28). Nefazodone is a highly selective antagonist at the 5-HT2 receptor subtype.
One effect that theophylline, nitroglycerin, isoproterenol, and histamine have in common is
Ans: Tachycardia
Theophylline does not ordinarily cause headache or postural hypotension. Nitroglycerin does not cause direct cardiac stimulation but does evoke a compensatory sympathetic reflex. Histamine does not cause bronchodilation.
A 23-year-old woman is using an albuterol inhaler for frequent acute episodes of asthma and complains of symptoms that she ascribes to the albuterol. Which of the following is not a recognized action of albuterol?
Ans: Diuretic effect
Albuterol is a 2-selective receptor agonist, but in moderate to high doses it induces 1 cardiac effects as well as 2-mediated smooth and skeletal muscle effects. It does not cause diuresis.
A 51-year-old patient with parkinsonism is being maintained on levodopa-carbidopa with adjunctive use of low doses of entacapone, but continues to have off-periods of akinesia. The most appropriate drug to “rescue” the patient but that will only provide temporary relief is
Ans: Apomorphine
Apomorphine, via subcutaneous injection, is used for temporary relief of off-periods of akinesia (“rescue”) in parkinsonian patients on dopaminergic drug therapy. Pretreatment with the antiemetic trimethobenzamide for 3 days is essential to prevent severe nausea
Your 37-year-old patient has been diagnosed with a rare metastatic carcinoid tumor. This neoplasm is releasing serotonin, bradykinin, and several unknown peptides. The effects of serotonin in this patient are most likely to include which one of the following?
Ans: Episodes of bronchospasm
Serotonin causes bronchospasm, but the other effects listed are not observed. Carcinoid is associated with diarrhea and hypertension.
A 36-year-old woman presents with symptoms of major depression that are unrelated to a general medical condition, bereavement, or substance abuse. She is not currently taking any prescription or over-the-counter medications. Drug treatment is to be initiated with paroxetine. In your information to the patient, you would tell her that
Ans: All the Above
- It is preferable that she does not take the drug in the evening
- Muscle cramps and twitches can sometimes occur
- She should tell you if she anticipates using other prescription drugs
- The antidepressant effects of paroxetine may take 2 weeks or more to become effective
All the statements are appropriate regarding the initiation of treatment with fluoxetine or other SSRI in a depressed patient. The SSRIs have CNS-stimulating effects and may cause agitation, anxiety, “the jitters,” and insomnia, especially early in treatment. Consequently, the evening is not the best time to take SSRI drugs.
Bradykinesia has made drug treatment necessary in a 60-year-old male patient with Parkinson’s disease, and therapy is to be initiated with levodopa.
Regarding the anticipated actions of levodopa, the patient would not be informed that
Ans: A netlike reddish to blue discoloration of the skin is a possible side effect.
In prescribing levodopa, the patient should be informed about adverse effects, including gastrointestinal distress, postural hypotension, and dyskinesias. It is reasonable to advise the patient that therapeutic benefits cannot be expected to continue indefinitely. Livedo reticularis (a netlike rash) is an adverse effect of treatment with amantadine.
A 16-year-old patient is in the emergency department receiving nasal oxygen. She has a heart rate of 125 bpm, a respiratory rate of 40 breaths/min, and a peak expiratory flow
Ans: Blockade of histamine receptors
Histamine does not appear to play a significant role in asthma, and antihistaminic drugs, even in high doses, are of little or no value. Antigen avoidance is well established. Blockade of leukotriene receptors with montelukast; inhibition of phospholipase with corticosteroids; and inhibition of mediator release with the IgE antibody are also useful.
Trifluoperazine was prescribed for a young male patient diagnosed as suffering from schizophrenia. He complains about the side effects of his medication. Which of the following is not likely to be on his list?
Ans: Excessive salivation
Phenothiazines such as trifluoperazine cause sedation and are antagonists at muscarinic and adrenoceptors. Postural hypotension, blurring of vision, and dry mouth are common autonomic adverse effects, as is constipation. Effects on the male libido may result from increased prolactin or from increased peripheral conversion of androgens to estrogens.
Which statement concerning the use of lithium in the treatment of bipolar affective disorder is accurate?
Ans: Lithium dosage may need to be decreased in patients taking thiazides
Clinical effects of lithium are slow in onset and may not be apparent before 1 or 2 weeks of daily treatment. High urinary levels of sodium inhibit renal tubular reabsorption of lithium, thus decreasing its plasma levels. Lithium clearance is decreased by distal tubule diuretics (eg, thiazides) because natriuresis stimulates a reflex increase in the proximal tubule reabsorption of both lithium and sodium. Any drug that can cross the blood-brain barrier can cross the placental barrier! Teratogenic risk is low, but use of lithium during pregnancy may contribute to low Apgar score in the neonate.
Oral medications are popular for the treatment of asthma in children because young children may have difficulty with the proper use of aerosol inhalers. Which of the following is an orally active inhibitor of leukotriene receptors?
Ans: Montelukast
Zileuton is an inhibitor of the lipoxygenase enzyme involved in the synthesis of leukotrienes. Montelukast and zafirlukast are leukotriene antagonists at the leukotriene receptor.
Increased serum levels of which of the following is associated with a decreased risk of atherosclerosis?
Ans: HDL
Increased serum concentrations of LDL and total cholesterol are associated with increased risk of atherosclerosis. High serum concentration of HDL cholesterol is associated with a decrease in the risk of atherosclerotic disease.
Bradykinesia has made drug treatment necessary in a 60-year-old male patient with Parkinson’s disease, and therapy is to be initiated with levodopa.
The prescribing physician will (or should) know that levodopa
Ans: Fluctuates in its effectiveness with increasing frequency as treatment continues
Levodopa causes less peripheral toxicity but more CNS or behavioral side effects when its conversion to dopamine is inhibited outside the CNS. The drug is not effective in antagonizing the akinesia, rigidity, and tremor caused by treatment with antipsychotic agents. Levodopa is a precursor of melanin and may activate malignant melanoma. Use of levodopa is not associated with pulmonary dysfunction.
A 10-year-old child has severe asthma and was hospitalized 5 times between the ages of 7 and 9. He is now receiving outpatient medications that have greatly reduced the frequency of severe attacks. Which of the following is most likely to have adverse effects when used daily over long periods for severe asthma?
Ans: Prednisone by mouth
If oral corticosteroids must be used, alternate-day therapy is preferred because it interferes less with normal growth in children.
A 35-year-old woman appears to have familial combined hyperlipidemia. Her serum concentrations of total cholesterol, LDL cholesterol, and triglyceride are elevated. Her serum concentration of HDL cholesterol is somewhat reduced.
Which of the following drugs is most likely to increase this patient’s triglyceride and VLDL cholesterol concentrations when used as monotherapy?
Ans: Cholestyramine
In some patients with familial combined hyperlipidemia and elevated VLDL, the resins increase VLDL and triglyceride concentrations even though they also lower LDL cholesterol.
A 16-year-old patient is in the emergency department receiving nasal oxygen. She has a heart rate of 125 bpm, a respiratory rate of 40 breaths/min, and a peak expiratory flow
Ans: Prednisone
Although extremely important in severe chronic asthma and status asthmaticus, corticosteroids do not have a demonstrable direct bronchodilator action.
A patient underwent a surgical procedure of 2 h. Anesthesia was provided by isoflurane, supplemented by intravenous midazolam and a nondepolarizing muscle relaxant. At the end of the procedure, a low dose of glycopyrrolate was administered followed by pyridostigmine.
The main reason for administering the muscarinic receptor antagonist was to
Ans: Prevent activation of cardiac muscarinic receptors
Acetylcholinesterase inhibitors used for reversing the effects of nondepolarizing muscle relaxants cause increases in ACh at all sites where it acts as a neurotransmitter. To offset the resulting side effects, including bradycardia, a muscarinic blocking agent is used concomitantly. Although atropine is effective, glycopyrollate is usually preferred because it lacks CNS effects.
A 9-year-old child is having learning difficulties at school. He has brief lapses of awareness with eyelid fluttering that occur every 5–10 min. Electroencephalogram (EEG) studies reveal brief 3-Hz spike and wave discharges appearing synchronously in all leads. Which drug would be effective in this child without the disadvantages of excessive sedation or tolerance development?
Ans: Ethosuximide
This child suffers from absence seizures, and 2 of the drugs listed are effective in this seizure disorder. Clonazepam is effective but exerts troublesome CNS-depressant effects, and tolerance develops with chronic use. Ethosuximide is not excessively sedating, and tolerance does not develop to its antiseizure activity. Valproic acid (not listed) is also used in absence seizures.
Which statement about ropinirole is accurate?
Ans: Warfarin may enhance the actions of ropinirole
Ropinirole is a dopamine D2 receptor activator and does not require bioactivation. Confusion, delusions, and hallucinations occur more frequently with dopamine receptor activators than with levodopa. The use of dopaminergic agents in combination with antimuscarinic drugs is common in the treatment of parkinsonism. Ropinirole is metabolized by hepatic CYP1A2, and its plasma levels may be increased by other substrates of this enzyme including caffeine and warfarin.
A 34-year-old male patient who was prescribed citalopram for depression has decided he wants to stop taking the drug. When questioned, he said that it was affecting his sexual performance. You ascertain that he is also trying to overcome his dependency on tobacco products. If you decide to reinstitute drug therapy in this patient, the best choice would be
Ans: Bupropion
The SSRIs and venlafaxine (an SNRI) can cause sexual dysfunction with decreased libido, erectile dysfunction, and anorgasmia. TCAs may also decrease libido or prevent ejaculation. Bupropion is the least likely antidepressant to affect sexual performance. The drug is also purportedly useful in withdrawal from nicotine dependence, which could be helpful in this patient.
Which statement concerning the barbiturates is accurate?
Ans: Alkalinization of the urine accelerates the elimination of phenobarbital
Withdrawal symptoms from use of the shorter-acting barbiturate secobarbital are more severe than with phenobarbital. The dose-response curve for benzodiazepines is flatter than that for barbiturates. Induction of liver drug-metabolizing enzymes occurs with barbiturates and may lead to decreases in half-life of other drugs. Flumazenil is an antagonist at BZ receptors and is used to reverse CNS depressant effects of benzodiazepines. As a weak acid (pKa, 7), phenobarbital will be more ionized (nonprotonated) in the urine at alkaline pH and less reabsorbed in the renal tubule.
A 57-year-old man has severe pulmonary hypertension and right ventricular hypertrophy. Which of the following agents causes vasodilation and may be useful in pulmonary hypertension?
Ans: Prostacyclin
Prostacyclin (PGI2) is a very potent vasodilator. All the other choices in the list are vasoconstrictors.
Regarding the clinical use of antidepressant drugs, which statement is accurate?
Ans: When selecting an appropriate drug for treatment of depression, the history of patient response to specific drugs is a valuable guide
No antidepressant has been shown to increase hepatic drug metabolism. MAO inhibitors (not TCAs), though now used infrequently, are the drugs most likely to be effective in depression with attendant anxiety, phobic features and hypochondriasis. SSRIs are usually associated with weight loss, at least during the first 6 months of treatment. There is no evidence that any SSRI is more effective than another, or more effective overall than a tricyclic drug, in treatment of major depressive disorder.
Which of the following best describes the mechanism of action of benzodiazepines?
Ans: Increase frequency of opening of chloride ion channels coupled to GABAA receptors
Benzodiazepines exert most of their CNS effects by increasing the inhibitory effects of GABA, interacting with components of the GABA-A receptor-chloride ion channel macromolecular complex to increase the frequency of chloride ion channel opening. Benzodiazepines do not affect GABA metabolism or release, and they are not GABA receptor agonists because they do not interact directly with the binding site for GABA.
A 19-year-old woman complains of severe dysmenorrhea. A uterine stimulant derived from membrane lipid in the endometrium is
Ans: Prostaglandin PGE2
Although serotonin and, in some species, histamine may cause uterine stimulation, these substances are not derived from membrane lipid. Similarly, oxytocin causes uterine contraction, but it is a peptide hormone secreted by the posterior pituitary. Prostacyclin relaxes the uterus
A 43-year-old very overweight man complains of not sleeping well and feeling tired during the day. He tells his physician that his wife is the cause of the problem because she wakes him up several times during the night because of his loud snores. This appears to be a breathing-related sleep disorder, so you should probably write a prescription for
Ans: None of the above
Benzodiazepines and barbiturates are contraindicated in breathing-related sleep disorders because they further compromise ventilation. In obstructive sleep apnea (pickwickian syndrome), obesity is a major risk factor. Buspirone is a selective anxiolytic not a hypnotic. The best prescription you can give this patient is to lose weight.
A patient with parkinsonism is being treated with levodopa. He suffers from irregular, involuntary muscle jerks that affect the proximal muscles of the limbs. Which of the following statements about these symptoms is accurate?
Ans: Other drugs that activate dopamine receptors can exacerbate dyskinesias in a patient taking levodopa
The form and severity of dyskinesias resulting from levodopa may vary widely in individual patients. Dyskinesias occur in up to 80% of patients receiving levodopa for long periods. With continued treatment, dyskinesias may develop at a dose of levodopa that was previously well tolerated. Muscarinic receptor blockers do not prevent their occurrence. They occur more commonly in patients treated with levodopa in combination with carbidopa or with other dopamine receptor agonists.
Mr Green is a 60-year-old former smoker with cardiac disease and severe chronic obstructive pulmonary disease (COPD) associated with frequent episodes of bronchospasm. Which of the following is a bronchodilator useful in COPD and least likely to cause cardiac arrhythmia?
Ans: Ipratropium
Ipratropium is the bronchodilator that is most likely to be useful in COPD without causing arrhythmias. Tiotropium is similar.
A 23-year-old woman suffers from recurrent episodes of angioneurotic edema with release of histamine and other mediators. Which of the following drugs is the most effective physiologic antagonist of histamine in smooth muscle?
Ans: Epinephrine
The smooth muscle effects of histamine are mediated mainly by H1 receptors. Cetirizine is a pharmacologic antagonist of histamine. Granisetron is a 5-HT3 antagonist. Sumatriptan is a 5-HT1D agonist. Ranitidine is a histamine antagonist but blocks the H2 receptor in the stomach and the heart, not H1 receptors in smooth muscle. Epinephrine has a physiologic antagonist action that reverses histamine’s effects on smooth muscle.
Haloperidol is not an appropriate drug for management of
Ans: The amenorrhea-galactorrhea syndrome
In addition to its use in schizophrenia and acute mania, haloperidol has been used in the management of intoxication due to phencyclidine (PCP) and in Tourette’s syndrome. Hyperprolactinemia and the amenorrhea-galactorrhea syndrome may occur as adverse effects during treatment with antipsychotic drugs, especially those like haloperidol that strongly antagonize dopamine receptors in the tuberoinfundibular tract.
A patient underwent a surgical procedure of 2 h. Anesthesia was provided by isoflurane, supplemented by intravenous midazolam and a nondepolarizing muscle relaxant. At the end of the procedure, a low dose of glycopyrrolate was administered followed by pyridostigmine.
A muscarinic receptor antagonist would probably not be needed for reversal of the skeletal muscle relaxant actions of a nondepolarizing drug if the agent used was
Ans: Pancuronium
One of the distinctive characteristics of pancuronium is that it can block muscarinic receptors, especially those in the heart. It has sometimes caused tachycardia and hypertension and may cause dysrhythmias in predisposed individuals.
A 24-year-old stockbroker has developed a “nervous disposition.” He is easily startled, worries about inconsequential matters, and sometimes complains of stomach cramps. At night he grinds his teeth in his sleep. There is no history of drug abuse. Diagnosed as suffering from generalized anxiety disorder, he is prescribed buspirone. His physician should inform the patient to anticipate
Ans: That the drug is likely to take a week or more to begin working
Buspirone is a selective anxiolytic with pharmacologic characteristics different from those of sedative-hypnotics. Buspirone has minimal effects on cognition or memory; it is not an additive with ethanol in terms of CNS depression; tolerance is minimal; and it has no dependence liability. Buspirone is not effective in acute anxiety because it has a slow onset of action.
An 82-year-old woman, otherwise healthy for her age, has difficulty sleeping. Triazolam is prescribed for her at one half of the conventional adult dose. Which statement about the use of triazolam in this elderly patient is accurate?
Ans: The patient may experience amnesia, especially if she also consumes alcoholic beverages
In elderly patients taking benzodiazepines, hypotension is far more likely than an increase in blood pressure. Elderly patients are more prone to the CNS depressant effects of hypnotics; a dose reduction of 50% may still cause excessive sedation with possible ambulatory impairment. Additive CNS depression occurs commonly with drugs used in over-the-counter cold medications, and rebound insomnia can occur with abrupt discontinuance of benzodiazepines used as sleeping pills. Alcohol enhances psychomotor depression and the amnestic effects of the benzodiazepines.
A 20-year-old woman is taking diphenhydramine for severe hay fever. Which of the following adverse effects is she most likely to report?
Ans: Sedation
H1 blockers do not activate muscarinic receptors, mediate vasoconstriction, or cause uterine cramping. They do not cause nervousness or anxiety. Diphenhydramine is a potent sedative.
A laboratory study of new H2 blockers is planned. Which of the following will result from blockade of H2 receptors?
Ans: Decreased cAMP in gastric mucosa
H2 receptors are Gs-protein-coupled receptors, like beta adrenoceptors. Blockade of this system will cause a decrease in cAMP.
Concerning the drugs used in parkinsonism, which statement is accurate?
Ans: Levodopa causes mydriasis and may precipitate an acute attack of glaucoma
The non-ergot dopamine agonists (pramipexole, ropinirole) are commonly used prior to levodopa in mild parkinsonism. The mydriatic action of levodopa may increase intraocular pressure; the drug should be used cautiously in patients with open-angle glaucoma and is contraindicated in those with angle-closure glaucoma. Antimuscarinic drugs may improve the tremor and rigidity of parkinsonism but have little effect on bradykinesia. Selegiline is a selective inhibitor of MAO type B.
The clinical use of succinylcholine, especially in patients with diabetes, is associated with
Ans: Aspiration of gastric contents
Fasciculations associated with succinylcholine may increase intragastric pressure with possible complications of regurgitation and aspiration of gastric contents. The complication is more likely in patients with delayed gastric emptying such as those with esophageal dysfunction or diabetes. Histamine release resulting from succinylcholine is not genetically determined.
A 58-year-old man with a history of hyperlipidemia was treated with a drug. The chart below shows the results of the patient’s fasting lipid panel before treatment and 6 mo after initiating drug therapy. Normal values are also shown. Which of the following drugs is most likely to be the one that this man received?
Trig Chol LDL VLDL HDL
Before treatment 1000 640. 120 500. 20
Six months after 300 275. 90 150. 40
Normal values 35
Ans: Niacin
This patient presents with striking hypertriglyceridemia, elevated VLDL cholesterol, and depressed HDL cholesterol. Six months after drug treatment was initiated, his triglyceride and VLDL cholesterol have dropped dramatically and his HDL cholesterol level has doubled. The drug that is most likely to have achieved all of these desirable changes, particularly the large increase in HDL cholesterol, is niacin. Although gemfibrozil lowers triglyceride and VLDL concentrations, it does not cause such large increases in HDL cholesterol and decreases in LDL cholesterol.
Which statement concerning the proposed mechanisms of action of anticonvulsant drugs is inaccurate?
Ans: Ethosuximide selectively blocks potassium ion (K+) channels in thalamic neurons
The mechanism of action of phenylsuccinimides such as ethosuximide involves blockade of T-type Ca2+ channels in thalamic neurons. Ethosuximide does not block K+ channels, which in any case would be likely to result in an increase (rather than a decrease) in neuronal excitability.
Which of the following drugs inhibits thromboxane synthesis much more effectively than prostacyclin synthesis?
Ans: Aspirin
Hydrocortisone and other corticosteroids inhibit phospholipase. Ibuprofen and indomethacin inhibit cyclooxygenase reversibly, whereas zileuton inhibits lipoxygenase. Because aspirin inhibits cyclooxygenase irreversibly, its action is more effective in platelets, which lack the ability to synthesize new enzyme, than in the endothelium.
A 35-year-old woman appears to have familial combined hyperlipidemia. Her serum concentrations of total cholesterol, LDL cholesterol, and triglyceride are elevated. Her serum concentration of HDL cholesterol is somewhat reduced.
If this patient is pregnant, which of the following drugs should be avoided because of a risk of harming the fetus?
Ans: Pravastatin
The HMG-CoA reductase inhibitors are contraindicated in pregnancy because of the risk of teratogenic effects.
The most likely explanation for the increased sensitivity of elderly patients after administration of a single dose of a benzodiazepine is
Ans: Changes in brain function accompanying aging
Decreased blood flow to vital organs, including the liver and kidney, occurs during the aging process. These changes may contribute to cumulative effects of sedative-hypnotic drugs. However, this does not explain the enhanced sensitivity of the elderly patient to a single dose of a central depressant, which appears to be due to changes in brain function that accompany aging.
A 30-year-old male patient is on drug therapy for a psychiatric problem. He complains that he feels “flat” and that he gets confused at times. He has been gaining weight and has lost his sex drive. As he moves his hands, you notice a slight tremor. He tells you that since he has been on medication he is always thirsty and frequently has to urinate. The drug he is most likely to be taking is
Ans: Lithium
Confusion, mood changes, decreased sexual interest, and weight gain are symptoms that may be unrelated to drug administration. On the other hand, psychiatric drugs are often responsible for such symptoms. Tremor and symptoms of nephrogenic diabetes insipidus are characteristic adverse effects of lithium that may occur at blood levels within the therapeutic range.
SSRIs are much less effective than tricyclic antidepressants in the management of
Ans: Chronic pain of neuropathic origin
The SSRIs are not effective in chronic pain of neuropathic origin. All the other uses of SSRIs are approved indications with clinical effectiveness equivalent or superior to that of tricyclic drugs. In addition to treatment of chronic pain states and depression, the tricyclics are also used to treat enuresis and attention deficit hyperkinetic disorder.
A previously healthy 40-year-old woman begins to suffer from slowed mentation, lack of coordination, and brief writhing movements of her hands that are not rhythmic. In addition, she has delusions of being persecuted. The woman has no history of psychiatric or neurologic disorders. Although further diagnostic assessment should be made, it is very likely that the most appropriate drug for treatment will be
Ans: Tetrabenazine
Although further diagnosis is desirable, choreoathetosis with decreased mental abilities and psychosis (paranoia) suggests that this patient has the symptoms of Huntington’s disease. Drugs that are partly ameliorative include agents that deplete dopamine (eg, tetrabenazine) or that block dopaminergic receptors (eg, haloperidol).
A 43-year-old man has heterozygous familial hypercholesterolemia. His serum concentrations of total cholesterol and LDL are markedly elevated. His serum concentration of HDL cholesterol, VLDL cholesterol, and triglycerides are normal or slightly elevated. The patient’s mother and older brother died of myocardial infarctions before the age of 50. This patient recently experienced mild chest pain when walking upstairs and has been diagnosed as having angina of effort. The patient is somewhat overweight. He drinks alcohol most evenings and smokes about 1 pack of cigarettes per week.
Consumption of alcohol is associated with which of the following changes in serum lipid concentrations?
Ans: Increased triglyceride
Chronic ethanol ingestion can increase serum concentrations of VLDL and triglycerides. This is one of the factors that places patients with alcoholism at risk of pancreatitis. Chronic ethanol ingestion also has the possibly beneficial effect of raising, not decreasing, serum HDL concentrations.
Which of the following drugs is most likely to be of value in obsessive-compulsive disorders?
Ans: Clomipramine
Clomipramine, a tricyclic agent, is a more selective inhibitor of 5-HT reuptake than other drugs in its class. This activity appears to be important in the treatment of obsessive-compulsive disorder. However, the SSRIs have now become the drugs of choice for this disorder because they are safer in overdose than tricyclics.
A 35-year-old woman appears to have familial combined hyperlipidemia. Her serum concentrations of total cholesterol, LDL cholesterol, and triglyceride are elevated. Her serum concentration of HDL cholesterol is somewhat reduced.
Which of the following is a major toxicity associated with gemfibrozil therapy?
Ans: Cholelithiasis
A major toxicity of the fibrates is increased risk of gallstone formation, which may be due to enhanced biliary excretion of cholesterol.
Inflammation is a complex tissue reaction that includes the release of cytokines, leukotrienes, prostaglandins, and peptides. Prostaglandins involved in inflammatory processes are typically produced from arachidonic acid by which of the following enzymes?
Ans: Cyclooxygenase-2
See Figure 18–1. Phospholipase A2 converts membrane phospholipid to arachidonic acid. Cyclooxygenases convert arachidonic acid to prostaglandins. COX-2 is the enzyme believed to be responsible for this reaction in inflammatory cells.
A young female patient suffers from absence seizures. Which of the following statements about her proposed drug management is NOT accurate?
Ans: She should be examined every 2 or 3 mo for deep tendon reflex activity
Ethosuximide and valproic acid are preferred drugs in absence seizures because they cause minimal sedation. However, valproic acid causes gastrointestinal distress and weight gain and is potentially hepatotoxic. In addition, its use in pregnancy has been associated with teratogenicity (neural tube defects). Peripheral neuropathy, including diminished deep tendon reflexes in the lower extremities, occurs with the chronic use of phenytoin, not valproic acid.
Which drug used in management of seizure disorders is most likely to elevate the plasma concentration of other drugs administered concomitantly?
Ans: Valproic acid
With chronic use, carbamazepine induces the formation of hepatic drug-metabolizing enzymes (as do phenobarbital and phenytoin). This action may lead to a decrease in the plasma concentration of other drugs used concomitantly. Valproic acid, an inhibitor of drug metabolism, can increase the plasma levels of many drugs, including carbamazepine, lamotrigine, phenobarbital, and phenytoin. Benzodiazepines (including clonazepam and diazepam), as well as gabapentin and vigabatrin, have no major effects on the metabolism of other drugs.
You are asked to consult on a series of cases of drug toxicities. Which of the following is a recognized adverse effect of cimetidine?
Ans: P450 hepatic enzyme inhibition
The older H1 blockers, not H2 blockers, cause blurred vision, orthostatic hypotension, and sleepiness. Neither group typically causes diarrhea. Cimetidine (unlike other H2 blockers) is a potent CYP3A4 inhibitor.
Which of the following in its parenteral form is life-saving in severe status asthmaticus and acts, at least in part, by inhibiting phospholipase A2?
Ans: Prednisone
Parenteral corticosteroids such as prednisolone (the active metabolite of prednisone) are lifesaving in status asthmaticus. They probably act by reducing production of leukotrienes
A 40-year-old patient is about to undergo cancer chemotherapy with a highly emetogenic (nausea- and vomiting-causing) drug combination. The antiemetic drug most likely to be included in her regimen is
Ans: Ondansetron
Ondansetron and other 5-HT3 antagonists have significant antiemetic effects. Diphenhydramine and prednisone are also used for this purpose.
A patient with a bleeding tendency presents in the hematology clinic. He is apparently taking large amounts of an unidentified drug that inhibits platelet activity. Which of the following directly and reversibly inhibits platelet cyclooxygenase?
Ans: ibuprofen
Aspirin is a direct but irreversible inhibitor of cyclooxygenase. NSAIDs other than aspirin (such as ibuprofen) are reversible inhibitors of COX. Corticosteroids reduce the synthesis of cyclooxygenase.
A newborn infant is diagnosed with transposition of the great vessels, wherein the aorta exits from the right ventricle and the pulmonary artery from the left ventricle. Which of the following drugs is likely to be used in preparation for surgical correction of this anomaly?
Ans: Prostaglandin PGE2
Infants with great vessel transposition pump venous blood to the aorta and oxygenated blood back to the lungs. Therefore, they require surgical correction as soon as they are strong enough to withstand the procedure. In the meantime, they are dependent on a patent ductus arteriosus to allow some oxygenated blood to flow from the left ventricle via the pulmonary artery to the aorta. The ductus can be prevented from closing by infusing the vasodilator PGE2.
A 22-year-old man is brought to the emergency department after suffering seizures resulting from an overdose of a drug he has been taking. His friends state that he took the drug orally and sometimes had insomnia after taking it. Which of the following is a direct bronchodilator that is most often used in asthma by the oral route and is capable of causing insomnia and seizures?
Ans: Theophylline
Theophylline is a bronchodilator that is active by the oral route. It causes insomnia in therapeutic doses and seizures in overdosage.
A recently bereaved 73-year-old female patient was treated with a benzodiazepine for several weeks after the death of her husband, but she did not like the daytime sedation it caused even at low dosage. Living independently, she has no major medical problems but appears rather infirm for her age and has poor eyesight. Because her depressive symptoms are not abating, you decide on a trial of an antidepressant medication. Which of the following drugs would be the most appropriate choice for this patient?
Ans: Sertraline
Older patients are more likely to be sensitive to antidepressant drugs that cause sedation, atropine-like adverse effects, or postural hypotension. Tricyclics and MAO inhibitors cause many autonomic side effects; mirtazapine and trazodone are highly sedating. Sertraline (or another SSRI) is often the best choice in such patients.
This drug, an antagonist at 5-HT2 receptors, is widely used for the management of insomnia.
Ans: Trazodone
Triazolam and zolpidem are effective hypnotic drugs, but they do not act via antagonism of serotonin 5-HT2 receptors. Trazodone is an antagonist at 5-HT2 receptors and has wide use as a sleeping aid, especially in patients with symptoms of affective disorder.
A young male patient recently diagnosed as schizophrenic develops severe muscle cramps with torticollis a short time after drug therapy is initiated with haloperidol. The best course of action would be to
Ans: Inject benztropine
Acute dystonic reactions are usually very painful and should be treated immediately with parenteral administration of a drug that blocks muscarinic receptors such as benztropine. Adding risperidone is not protective, and fluphenazine is as likely as haloperidol to cause acute dystonia. Oral administration of diphenhydramine is a possibility, but the patient may find it difficult to swallow and it would take a longer time to act.
Which drug is most often associated with hypotension caused by histamine release?
Ans: Tubocurarine
Hypotension may occur with tubocurarine and with the spasmolytic drug tizanidine. In the case of tubocurarine, the decrease in blood pressure may be due partly to histamine release and to ganglionic blockade. Tizanidine causes hypotension via 2-adrenoceptor activation like its congener clonidine.
Which statement concerning the pharmacokinetics of antiseizure drugs is accurate?
Ans: Although ethosuximide has a half-life of approximately 40 h, the drug is usually taken twice a day
The enzyme-inducing activity of phenytoin has led to symptoms of opioid withdrawal, presumably because of an increase in the rate of metabolism of methadone. Monitoring of plasma concentration of phenytoin may be critical in establishing an effective dosage because of nonlinear elimination kinetics at high doses. Valproic acid has no effect on porphyrin synthesis. Vigabatrin does not affect the metabolism of oral contraceptives. Twice-daily dosage of ethosuximide reduces the severity of adverse gastrointestinal effects.
Which drug used in the maintenance treatment of patients with tonic-clonic or partial seizure states increases the hepatic metabolism of many drugs including both warfarin and phenytoin?
Ans: Phenobarbital
Chronic administration of phenobarbital increases the activity of hepatic drug-metabolizing enzymes, including several cytochrome P450 isozymes. This can increase the rate of metabolism of drugs administered concomitantly, resulting in decreases in the intensity and duration of their effects.
