Indicate the beta adrenoreceptor antagonist which has partial beta–agonist activity:

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: 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.

Correct Answer: C

Rationale: Rationale: 1. Levodopa is a dopamine precursor used in Parkinson's disease. 2. Gastrointestinal irritation is a common side effect due to increased dopamine in the gut. 3. Cardiovascular effects like tachycardia and hypotension can occur due to dopamine's influence on the heart. 4. Mental disturbances and withdrawal may result from dopamine fluctuations. 5. Amantadine (A) and Selegiline (D) do not typically cause these specific side effects. 6. Benztropine (B) is an anticholinergic used to treat extrapyramidal symptoms, not known for these adverse effects.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Methadone causes tolerance and physical dependence more slowly than morphine due to its longer half-life. 2. Methadone is more effective orally as it has high bioavailability compared to morphine. 3. Withdrawal from methadone is less severe but more prolonged, making it easier to taper off. 4. Therefore, all the statements are true, making option D the correct answer. Summary: A. Incorrect - Methadone causes tolerance and physical dependence more slowly than morphine. B. Incorrect - Methadone is more effective orally compared to morphine. C. Incorrect - Withdrawal from methadone is less severe but more prolonged.

Correct Answer: C

Rationale: The correct answer is C: Haloperidol. Haloperidol is considered a typical antipsychotic drug due to its high affinity for dopamine D2 receptors and its strong dopamine-blocking effects. Typical antipsychotics primarily target dopamine receptors, leading to the alleviation of positive symptoms of psychosis. Clozapine (A), Quetiapine (B), and Olanzapine (D) are atypical antipsychotics, as they target multiple neurotransmitter systems, including serotonin and dopamine. They are preferred for their reduced risk of extrapyramidal side effects compared to typical antipsychotics.