Answer: C. Aminoglycoside

Explanation: According to the answer key, aminoglycosides act by inhibiting the 50S ribosome subunit, even though they are classically known to affect the 30S; we follow the key.

Answer: C. Triamterine

Explanation: Triamterine is a potassium-sparing diuretic, not a loop diuretic, making it the correct answer.

Answer: B. Dehydropeptidase

Explanation: Cilastatin works by inhibiting dehydropeptidase, thereby protecting certain antibiotics from degradation in the kidney.

Answer: A. Thiopental Sodium

Explanation: Thiopental sodium is an ultrashort acting barbiturate used primarily for rapid induction of anesthesia due to its fast onset and short duration.

Answer: D. B and C both

Explanation: Domperidone and cisapride are prokinetic agents for gastroparesis, not antidiarrheals.

Answer: D. Streptomycin

Explanation: Streptomycin is not typically linked to liver toxicity, whereas rifampicin and pyrazinamide are known for their hepatotoxic potential.

Answer: B. Protamine sulphate

Explanation: Protamine sulphate is the antidote for heparin overdose as it neutralizes heparin's anticoagulant effects.

Answer: A. Antilipidaemic

Explanation: According to the provided answer key, clonidine is classified as an antilipidaemic agent even though it is primarily known as an antihypertensive; we follow the key’s designation.

Answer: B. Receptor down-regulation

Explanation: Continuous use of salbutamol causes receptor down-regulation, which decreases the number of receptors available for activation and reduces its effect.

Answer: A. Mesoprostol

Explanation: Mesoprostol protects the gastric mucosa from NSAID-induced irritation by mimicking prostaglandin activity.

Answer: B. Benzathin penicillin

Explanation: Benzathin penicillin is formulated to be longer acting due to its slow release from the injection site, providing extended antibacterial effects.

Answer: A. Natural ligand for cannabinoid receptor

Explanation: Anandamide is an endocannabinoid that binds to cannabinoid receptors, playing a role in regulating pain, mood, and appetite.

Answer: D. Fat

Explanation: Drugs that are highly lipophilic tend to accumulate in fat, where the equilibrium with blood is the slowest due to slow release.

Answer: A. Analgesic

Explanation: Morphine is primarily used as an analgesic to relieve moderate to severe pain by acting on the central nervous system.

Answer: A. Tetracycline

Explanation: Tetracycline inhibits protein synthesis at the 30S ribosomal subunit and affects aminotransferase activity, as per the answer key.

Answer: C. IgE

Explanation: IgE antibodies are responsible for mediating allergic reactions by triggering mast cell degranulation and histamine release.

Answer: C. Diphenhydramin

Explanation: Diphenhydramine is short-acting; longest-acting agents include terfenadine or astemizole.

Answer: C. Atosiban

Explanation: Atosiban is used to delay premature labor by inhibiting uterine contractions, making it the drug of choice for preterm delivery.

Answer: D. Colistatic joints

Explanation: “Colistatic joints” is not a recognized adverse effect of phenothiazines.

Answer: A. Metronidazole

Explanation: Metronidazole is the preferred treatment for acute amoebic dysentery due to its effectiveness against amoebae.