Epinephrine decreases intracellular camp levels by acting on:

Correct Answer: B

Rationale: The correct answer is B: α2 receptor. Epinephrine binds to α2 receptors, leading to inhibition of adenylate cyclase activity, which decreases intracellular cAMP levels. α1 receptors are Gq-coupled and increase intracellular calcium levels. Beta1 receptors are also Gs-coupled, leading to increased cAMP levels. Beta2 receptors, like α2 receptors, are Gi-coupled and decrease cAMP levels. Therefore, the correct answer is B because epinephrine acts on α2 receptors to decrease cAMP levels.

Correct Answer: B

Rationale: The correct answer is B: Sleep disorders. Hypnotic drugs are primarily used to treat sleep disorders by promoting sleep or helping to manage insomnia. They act on the central nervous system to induce and maintain sleep. Psychosis (A) is typically treated with antipsychotic medications, narcolepsy (C) is treated with stimulant medications, and Parkinsonian disorders (D) are managed with medications that target dopamine levels in the brain. Therefore, the correct choice is B as it aligns with the pharmacological action and intended therapeutic effect of hypnotic drugs.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Carbamazepine, valproate, and phenytoin are all antiepileptic drugs used to treat partial and generalized tonic-clonic seizures. Each drug works through different mechanisms to help control seizure activity. Choosing "All of the above" ensures that all appropriate treatment options are considered for managing these types of seizures. Options A, B, and C alone are incorrect because each drug individually is effective but may not cover all seizure types.

Correct Answer: C

Rationale: Certainly! Benztropine is preferred in drug-induced parkinsonism as it acts as an anticholinergic agent, counteracting excess acetylcholine caused by certain drugs. Levodopa (A) and dopamine (D) are not effective as they can worsen symptoms. Bromocriptine (B) is a dopamine agonist used in idiopathic Parkinson's disease, not drug-induced parkinsonism.

Correct Answer: D

Rationale: The correct answer is D: Therapeutic doses of opioid analgesics do not affect body temperature. Opioid analgesics primarily act on the central nervous system to provide pain relief, without directly impacting body temperature regulation. Choices A and B are incorrect as opioid analgesics do not have a significant impact on altering body temperature. Choice C is incorrect as opioid analgesics do not affect body heat loss mechanisms. Thus, the correct answer is D because opioid analgesics do not have a direct effect on body temperature regulation.