Parasympathomimetic drugs cause:

Correct Answer: C

Rationale: Parasympathomimetic drugs mimic the effects of the parasympathetic nervous system. Stimulation of the parasympathetic system leads to a decrease in heart rate (bradycardia). This is why choice C is correct. Bronchodilation (A) is caused by sympathetic stimulation, mydriasis (B) is caused by sympathetic stimulation, and constipation (D) can be caused by anticholinergic drugs, which have the opposite effect of parasympathomimetic drugs.

Correct Answer: A

Rationale: The correct answer is A because alpha agonists cause mydriasis (pupil dilation), not miosis (pupil constriction). Alpha agonists like phenylephrine work by stimulating alpha receptors in the iris dilator muscle, leading to pupil dilation. Therefore, choice A is incorrect. Choices B, C, and D are incorrect because alpha agonists do cause mydriasis, beta antagonists do decrease the production of aqueous humor, and alpha agonists do increase the outflow of aqueous humor from the eye, respectively.

Correct Answer: C

Rationale: Rationale: 1. Pindolol is a non-selective beta-blocker with intrinsic sympathomimetic activity (partial beta-agonist). 2. It competes with catecholamines for beta-adrenergic receptors, reducing heart rate and blood pressure. 3. Propranolol (A) and metoprolol (B) are non-selective beta-blockers without partial agonist activity. 4. Betaxolol (D) is a selective beta-1 blocker without partial agonist activity. Summary: Pindolol (C) is the correct choice due to its partial beta-agonist activity, which distinguishes it from the other options that lack this property.

Correct Answer: B

Rationale: The correct answer is B: Triazolam. Triazolam has the shortest elimination half-life among the options provided, typically around 2-5 hours. This is due to its rapid metabolism and elimination from the body. In comparison, Temazepam (A) has a longer half-life of around 8-20 hours, Flurazepam (C) has a half-life of 40-250 hours, and Diazepam (D) has a half-life of 20-100 hours. Therefore, Triazolam is the best choice for short-term hypnotic effects due to its quick elimination from the body.

Correct Answer: A

Rationale: The correct answer is A: Carbamazepine. This drug is the drug of choice for partial seizures due to its efficacy in controlling focal seizures and its broad spectrum of activity. Carbamazepine works by blocking voltage-gated sodium channels, reducing neuronal excitability. Rationale: - Carbamazepine is a common first-line treatment for partial seizures. - It is effective in controlling focal seizures. - It has a broad spectrum of activity against various types of seizures. - Carbamazepine's mechanism of action involves blocking sodium channels, reducing neuronal excitability. Summary of other choices: - B: Ethosuximide is primarily used for absence seizures, not partial seizures. - C: Diazepam is a short-acting benzodiazepine used for acute seizure management, not as a primary treatment for partial seizures. - D: Lamotrigine is more commonly used for generalized seizures and may not be as effective for controlling partial seizures.