Which of the following opioid analgesics is a partial mu receptor agonist?

Correct Answer: C

Rationale: Buprenorphine is a partial mu receptor agonist, meaning it activates the mu receptors but to a lesser extent compared to full agonists like morphine. Buprenorphine's unique pharmacological profile includes partial agonist activity at mu receptors, along with antagonist activity at kappa receptors. This combination results in a ceiling effect on respiratory depression and a lower risk of abuse potential compared to full agonists. Methadone is a full mu receptor agonist, morphine is a full mu receptor agonist, and sufentanyl is a potent full mu receptor agonist but is not a partial agonist like buprenorphine.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Tricyclic antidepressants like Amitriptyline have all three effects. Antimuscarinic action leads to dry mouth, constipation. Antihistaminic action causes sedation. Alpha adrenoreceptor-blocking action results in orthostatic hypotension. These side effects are common with tricyclic antidepressants due to their pharmacological properties.

Correct Answer: C

Rationale: The correct answer is C: Piracetam. Piracetam is a nootropic agent that has shown potential in improving cognitive functions and enhancing cerebral blood flow, making it beneficial for cerebral stroke treatment. Pantocrin (A) is a general stimulant, Sydnocarb (B) is primarily used for ADHD and narcolepsy, and Caffeine (D) is a CNS stimulant but lacks specific benefits for cerebral stroke treatment. In summary, Piracetam is the correct choice due to its specific effects on cerebral function and blood flow, while the other options are not tailored for stroke treatment.

Correct Answer: D

Rationale: The correct answer is D because overdoses of cocaine can lead to respiratory depression, arrhythmias, and seizures simultaneously, resulting in rapid fatality. Cocaine affects the central nervous system, causing respiratory depression and seizures, while also affecting the heart's electrical activity, leading to arrhythmias. Therefore, all options A, B, and C can occur in combination during a cocaine overdose, contributing to its rapid fatality. The other choices are incorrect because they do not encompass the range of potential fatal outcomes associated with cocaine overdose.

Correct Answer: D

Rationale: The correct answer is D: Theophylline. Theophylline is a bronchodilator drug related to xanthine due to its chemical structure being a xanthine derivative. It works by relaxing the smooth muscles in the airways, thus dilating the bronchioles and improving airflow in conditions like asthma and COPD. A: Atropine is not a xanthine derivative and is mainly used to treat bradycardia and in emergency situations like poisoning. B: Orciprenaline is a beta-2 adrenergic agonist, not a xanthine derivative, used for bronchodilation in conditions like asthma and COPD. C: Adrenaline is a catecholamine and acts as a non-selective adrenergic agonist, primarily used in emergency situations like anaphylaxis and cardiac arrest. It is not a xanthine derivative. In summary, Theophylline is the correct choice