Which of the following antiseizure drugs produces a voltage-dependent inactivation of sodium channels?

Correct Answer: D

Rationale: The correct answer is D because all of the antiseizure drugs listed (Lamotrigine, Carbamazepin, Phenytoin) produce voltage-dependent inactivation of sodium channels. This mechanism helps to control neuronal excitability and prevent seizure activity. Lamotrigine inhibits voltage-gated sodium channels by stabilizing their inactive state. Carbamazepin and Phenytoin also act by blocking sodium channels in a voltage-dependent manner. Therefore, all of these drugs are effective in preventing seizures by modulating sodium channel function. The other choices (A, B, C) are incorrect because they individually target sodium channels through voltage-dependent inactivation, distinguishing them from other antiseizure drugs that act through different mechanisms.

Correct Answer: B

Rationale: The correct answer is B: Pentazocine. Pentazocine is a mixed opioid agonist-antagonist that can increase pulmonary arterial pressure and myocardial work due to its kappa agonist activity. Morphine (A) primarily acts on mu-opioid receptors and does not significantly affect pulmonary arterial pressure. Meperidine (C) can cause hypotension rather than an increase in pulmonary arterial pressure. Methadone (D) is a synthetic opioid that has a long duration of action but does not typically cause a significant increase in pulmonary arterial pressure or myocardial work.

Correct Answer: C

Rationale: The correct answer is C: Clopheline. Clopheline is a centrally acting alpha-2 adrenergic agonist known for its analgesic effects by modulating pain perception in the central nervous system. Reserpine (A) is not an analgesic drug but rather a monoamine depletor. Propranolol (B) is a beta-blocker primarily used for cardiac conditions, not for its analgesic properties. Prazosin (D) is an alpha-1 adrenergic antagonist mainly used for hypertension and not known for its analgesic effects. Therefore, the correct answer is C as it directly acts on the central nervous system to provide analgesia.

Correct Answer: C

Rationale: The correct answer is C: Moclobemide. Moclobemide is a selective short-acting MAO-A inhibitor, which means it specifically targets the MAO-A enzyme, leading to increased levels of serotonin and norepinephrine. This helps alleviate symptoms of depression. Maprotiline (A) is a tetracyclic antidepressant, Amitriptyline (B) is a tricyclic antidepressant, and Selegiline (D) is a MAO-B inhibitor used for Parkinson's disease, not for depression. Therefore, C is the correct answer as it matches the criteria of being a selective short-acting MAO-A inhibitor.

Correct Answer: D

Rationale: The correct answer is D: Significant abuse potential. Cordiamine is primarily used as a cardiac analeptic, respiratory analeptic, and coronarodilatator, meaning it stimulates cardiac and respiratory functions and dilates coronary blood vessels. There is no evidence or indication that cordiamine has significant abuse potential. It is not a psychoactive substance and does not produce euphoria or addiction. Therefore, option D is the correct answer as it does not align with the principal properties of cordiamine.