Which of the following sympathomimetics is used in the therapy of bronchial asthma?

Correct Answer: A

Rationale: The correct answer is A: Formoterol. It is a long-acting beta2-adrenergic agonist used in bronchial asthma therapy to dilate airways by relaxing smooth muscles. Norepinephrine (B) is a vasopressor, not used in asthma. Methoxamine (C) is an alpha1-adrenergic agonist, not indicated for asthma. Dobutamine (D) is a beta1-adrenergic agonist mainly used in heart failure, not asthma. Formoterol's mechanism of action aligns with the therapeutic goal of bronchial asthma treatment, making it the correct choice.

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: A

Rationale: Certainly! Chlorpromazine is the correct answer as it is a typical antipsychotic known to induce parkinsonian syndromes as a side effect due to its dopamine-blocking properties. This leads to a decrease in dopamine levels and imbalance in the basal ganglia function, resulting in symptoms resembling Parkinson's disease. Diazepam, Triazolam, and Carbamazepine do not typically induce parkinsonian syndromes as they do not directly affect dopamine levels or basal ganglia function.

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.