Review of Pharmacology - 9E (2015)

Review of Pharmacology
Central Nervous System
386
272. Ans. (a) Clozapine (Ref: KDT 6/e p429)
273. Ans. (d) Hypercalcemia (Ref: K.D.T. 6/e p435)
274. Ans. (c) Clozapine (Ref: K.D.T. 6/e p429)
275. Ans. (a) Bupropion (Ref: Katzung 11/e p562)
276. Ans. (a) Imipramine (Ref: KDT 6/e p449)
277. Ans (a) Intravenous dantrolene (Ref: Harrison 18th/147)
The current treatment of choice for malignant hyperthermia is the intravenous administration of dantrolene
Other important measures are:
• Discontinuation of triggering agents
• Supportive therapy directed at correcting hyperthermia, acidosis, and organ dysfunction.
278. Ans. (b) Kappa (Ref: KDT 7/e p79)
Dysphoria and psychomimetics effects are caused by kappa receptors.
Actions of mu receptors are:
S – Sedation
A – Analgesia
C – Constipation
R – Respiratory depression
U – Euphoria
M – Miosis
279. Ans. (a) Diazepam (Ref: CMDT 2014/939)
Treatment with anticonvulsants is generally not required for alcohol withdrawal seizures, since they are self limited. Benzodiazepines
(diazepam or lorazepam) are effective and safe for preventing further seizures.
280. Ans. (b) Fomepizole acts by inhibiting aldehyde dehydrogenase (Ref: Katzung 12/e p398)
Fomepizole inhibits alcohol dehydrogenase and not aldehyde dehydrogenase
• Serum methanol concentration above 20 mg/dl is an indication to start treatment and above 50 mg/dl is for hemodialysis.
• Metabolic product formaldehyde and formic acid is responsible for blindness and high anion gap metabolic acidosis
• Three specific modalities of treatment are:
––
Inhibit formation of toxic metabolites by inhibiting alcohol dehydrogenase by fomepizole or ethanol
––
Hemodialysis
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Alkalinization to counter metabolic acidosis.
281. Ans. (b)IV naloxone (Ref: Kaplan & Sadock’s Comprehensive Textbook of Psychiatry 9th/1375-76, 1384)
The decreased bowel sounds (constipation), respiratory depression, pin point pupil and history of heroin addiction strongly
points toward the diagnosis of acute opioid poisoning. The drug of choice for acute opioid poisoning is intravenous
naloxone.
282. Ans. (a) Pethidine (Ref: Goodman Gilman 12th/499, 504)
• Pethidine (meperidine) is metabolized to form nor-pethidine which is excreted by kidneys. It has long half life (15-20
hours) as compared to pethidine (3 hours). Accumulation of this metabolite resulting in excitatory syndrome including
hallucinations, tremors, muscle twitches, dilated pupils, hyperactive reflexes and convulsions. Renal failure increases
the likelihood of toxicity and thus pethidine should be avoided.
• Morphine produces morphine-6-glucuronide which can accumulate in renal failure. The actions of this metabolite are
similar to morphine. In patients with renal failure morphine has more potency and longer duration of action due to
accumulation of morphine-6-glucuronide and thus need to be given in lower doses
283. Ans. (c) Seizures (Ref. Goodman and Gilman 12th/511)
Antagonism of opioid effects by naloxone is often accompanied by an ‘OVERSHOOT” phenomenon.
• Respiratory rate depressed by opioids transiently becomes higher than before the period of depression.
• Rebound release of catecholamines may cause hypertension, tachycardia and ventricular arrhythmias.
• Pulmonary edema also has been reported after naloxone administration.
284. Ans. (c) Flumazenil (Ref: Katzung, 11/e p395, Goodman and Gilman, 11/e p383- 384)
Flumazenil is a benzodiazepine antagonist used for treat of benzodiazepine overdose and not for alcohol dependence.
285. Ans. (d) Amphetamine (Ref: Katzung 11/e p565)
MDMA is also called Rave drug and ecstasy
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