Gabapentin acts by

Correct Answer: D

Rationale: The correct answer is D: Promotes GABA release. Gabapentin increases the release of GABA, an inhibitory neurotransmitter in the brain, which helps to reduce abnormal electrical activity and alleviate pain. This mechanism of action is different from choices A, B, and C, as Gabapentin does not bind to GABAA or GABAB receptors nor inhibit GABA destruction. It is important to understand the specific pharmacological actions of Gabapentin to grasp its therapeutic effects accurately.

Correct Answer: C

Rationale: The correct answer is C: Both Morphine and Codeine. Opioids like morphine and codeine act on opioid receptors in the brain and spinal cord to provide pain relief, suppress cough reflex, and slow down gut motility to relieve diarrhea. Morphine is a potent opioid used for moderate to severe pain, while codeine is a milder opioid often used for mild to moderate pain. Both drugs are known to provide relief for pain, cough, and diarrhea due to their shared pharmacological actions on the body. Therefore, the correct choice is C as both morphine and codeine are effective in providing symptomatic relief for pain, cough, and diarrhea. Choices A, B, and D are incorrect as they do not accurately reflect the pharmacological properties of opioids like morphine and codeine in providing relief for these specific symptoms.

Correct Answer: A

Rationale: The correct answer is A: Partial agonist at Mu receptor. Buprenorphine is a partial agonist at the Mu opioid receptor, meaning it activates the receptor to produce a partial response compared to a full agonist. This property allows for reduced risk of respiratory depression and overdose compared to full agonists. Choices B, C, and D are incorrect because buprenorphine does not act as a full agonist at either the Mu or Kappa receptors. It is important to understand the pharmacological properties of buprenorphine to optimize its use in clinical practice.

Correct Answer: A

Rationale: The correct answer is A: Prostaglandins. Prostaglandins are most associated with labor as they play a key role in promoting uterine contractions. They are synthesized in the uterus and stimulate smooth muscle contractions, leading to the initiation and progression of labor. Thromboxanes primarily regulate platelet function and vasoconstriction, not uterine contractions. Leukotrienes are involved in inflammatory responses and immune regulation, not specifically labor. NSAIDs inhibit prostaglandin synthesis, which can hinder labor progression, making them an unlikely choice for promoting uterine contractions.

Correct Answer: D

Rationale: The correct answer is D because the first pass effect refers to the amount of drug that is lost due to hepatic metabolism when a drug is absorbed from the gastrointestinal tract after oral administration. This process occurs before the drug reaches systemic circulation, reducing the bioavailability of the drug. Option A is incorrect as hepatic artery does not eliminate the drug. Option B is incorrect as it refers to drug excretion via stool. Option C is incorrect as it refers to drug destruction by stomach acidity, not hepatic metabolism.