Acute attack of migraine can be treated by:

Correct Answer: B

Rationale: The correct answer is B: Ergotamine. Ergotamine is a vasoconstrictor that helps alleviate migraine symptoms by constricting blood vessels in the brain. It is commonly used to treat acute migraine attacks. Prazosin (A) is an alpha-blocker used for hypertension, not migraines. Propranolol (C) is a beta-blocker used for migraine prevention, not acute treatment. Amphetamine (D) is a stimulant used for ADHD, not migraine treatment. Ergotamine's vasoconstrictive properties make it effective for treating acute migraines.

Correct Answer: D

Rationale: The correct answer is D: They increase renin activity. Beta blockers block beta-adrenergic receptors, leading to decreased renin secretion and ultimately decreased renin activity. This results in reduced renin-angiotensin-aldosterone system activation, leading to decreased blood pressure. Choices A, B, and C are incorrect because beta blockers are known to decrease blood pressure, propranolol is extensively metabolized in the liver, and atenolol is eliminated mainly unchanged in urine.

Correct Answer: A

Rationale: The correct answer is A because dopamine is not effective orally due to its inability to cross the blood-brain barrier. Dopamine is mainly metabolized by MAO and COMT enzymes (B). It is primarily excreted in the urine as homovanillic acid, not vanillylmandelic acid (C). Dopamine stimulates dopamine receptors (D), not α, β1, and D receptors.

Correct Answer: B

Rationale: Dobutamine is a positive inotrope that increases cardiac contractility, making it a suitable choice for treating heart failure by improving cardiac output. It is not typically used for hypertension, glaucoma, or arrhythmias. Hypertension is usually managed with antihypertensive medications like ACE inhibitors or beta-blockers. Glaucoma is treated with medications that reduce intraocular pressure. Arrhythmias are commonly managed with antiarrhythmic drugs or procedures such as ablation. Therefore, choice B, heart failure, is the correct answer for the use of dobutamine.

Correct Answer: D

Rationale: The correct answer is D: Blockade of acetylcholine release from all cholinergic nerves. Botulinum toxin exerts its effects by inhibiting the release of acetylcholine from presynaptic nerve terminals at neuromuscular junctions. This leads to muscle paralysis, which is a characteristic feature of botulism. A: Massive release of adrenaline from the adrenal medulla is incorrect because botulinum toxin does not affect the adrenal medulla or adrenaline release. B: Blockade of alpha and beta adrenergic receptors is incorrect because botulinum toxin does not directly block adrenergic receptors. C: Stimulation of acetylcholinesterase enzyme is incorrect because botulinum toxin inhibits acetylcholine release rather than stimulating acetylcholinesterase. In summary, the correct answer D directly correlates with the mechanism of action of Botulinum toxin, while the other choices are unrelated to how Botulinum toxin exerts