Which of the following drugs is associated with Stevens-Johnson syndrome?

Correct Answer: D

Rationale: Step 1: Ethosuximide is the correct answer as it is a known trigger for Stevens-Johnson syndrome due to its association with hypersensitivity reactions. Step 2: Valproic acid can cause liver toxicity but is not typically linked to Stevens-Johnson syndrome. Step 3: Quinidine is associated with drug-induced lupus but not commonly known to cause Stevens-Johnson syndrome. Step 4: Isoniazid is linked to drug-induced hepatitis but not typically associated with Stevens-Johnson syndrome. In summary, Ethosuximide is the correct choice due to its well-documented association with Stevens-Johnson syndrome, while the other options are linked to different adverse effects.

Correct Answer: B

Rationale: The correct answer is B: Protease inhibitor. Drugs ending in the suffix (navir) are commonly used to inhibit protease enzymes in viruses, particularly in the treatment of HIV/AIDS. Protease inhibitors disrupt viral replication by preventing the cleavage of viral proteins, thus inhibiting the production of new infectious viral particles. Choice A, Antidepressant, is incorrect as drugs used to treat depression usually end in (ine) or (pram). Choice C, Beta antagonist, is incorrect as drugs affecting beta receptors typically end in (olol) or (lol). Choice D, H antagonist, is incorrect as drugs targeting histamine receptors usually end in (ine) or (idine).

Correct Answer: C

Rationale: The correct answer is C: Sedation. Opioid analgesics like dextromethorphan and methadone are primarily used for pain management, not sedation. They work by binding to opioid receptors in the brain to reduce pain perception. Pulmonary edema can be managed with diuretics, cough suppression with antitussives, and sedation with sedatives/hypnotics. Therefore, sedation is not a condition typically treated with opioid analgesics.

Correct Answer: A

Rationale: The correct answer is A: Flumazenil. Flumazenil is a specific benzodiazepine receptor antagonist that can reverse the effects of benzodiazepine toxicity by competitively inhibiting the binding of benzodiazepines to their receptors. It works by reversing the sedative and respiratory depressant effects of benzodiazepines. Methylene blue (B) is used to treat methemoglobinemia, not benzodiazepine toxicity. Deferoxamine (C) is used for iron toxicity. Alkalinizing urine (D) is used to enhance the excretion of weak acids in the urine, not for benzodiazepine toxicity.

Correct Answer: C

Rationale: The correct answer is C: CaEDTA. Calcium disodium ethylenediaminetetraacetic acid (CaEDTA) is a chelating agent used to treat lead poisoning by binding to lead ions in the bloodstream and enhancing their excretion through urine. It forms stable complexes with lead, reducing its toxicity. Naloxone (A) is an opioid receptor antagonist, used to reverse opioid overdose. Nitrite (B) is used in cyanide poisoning. Dialysis (D) is not effective in removing lead from the body as lead is not effectively dialyzable.

Correct Answer: A

Rationale: The correct answer is A: COPD. Ephedrine is a sympathomimetic drug that acts on alpha and beta adrenergic receptors, leading to vasoconstriction and increased heart rate. It is used to treat hypotension and congestion by increasing blood pressure and dilating airways, respectively. Incontinence is not typically treated with Ephedrine. However, COPD involves bronchoconstriction, which can worsen with Ephedrine due to its vasoconstrictive effects. Therefore, Ephedrine is not used to treat COPD.

Correct Answer: A

Rationale: The correct answer is A: Quinidine. Quinidine is a class IA antiarrhythmic drug that blocks sodium channels in a use-dependent manner, which means it preferentially blocks channels that are open or have a rapid firing rate during depolarization. This action results in a decrease in conduction velocity and refractory period. Disopyramide is a class IA antiarrhythmic but does not specifically block sodium channels. Amiodarone is a class III antiarrhythmic that primarily affects potassium channels. Propafenone is a class IC antiarrhythmic that has minimal effects on sodium channel blockade. Therefore, Quinidine is the correct choice as a class IA sodium channel blocker.

Correct Answer: D

Rationale: The correct answer is D: Projectile vomiting. Nitroglycerin is not directly associated with causing projectile vomiting. Nitroglycerin commonly causes headaches due to vasodilation, tachycardia due to decreased preload, and dizziness due to hypotension. Projectile vomiting is not a typical side effect of Nitroglycerin toxicity.

Correct Answer: A

Rationale: The correct answer is A: Insomnia. Levothyroxine is a thyroid hormone replacement medication used to treat hypothyroidism. An overdose of levothyroxine can lead to hyperthyroidism symptoms, such as insomnia. This occurs due to an excess of thyroid hormone in the body, which can increase metabolism and disrupt sleep patterns. The other choices (B: Constipation, C: Drowsiness, D: Hypoactive deep-tendon reflexes) are not typical manifestations of a levothyroxine overdose. Constipation and drowsiness are more commonly associated with hypothyroidism, the condition being treated with levothyroxine. Hypoactive deep-tendon reflexes are not a typical symptom of either hypothyroidism or hyperthyroidism.