MAO is localized in

Correct Answer: C

Rationale: MAO (monoamine oxidase) is an enzyme that plays a crucial role in the metabolism of neurotransmitters in the central nervous system. The correct answer is C) Mitochondrial membrane. MAO is localized in the outer mitochondrial membrane of neurons. This positioning allows it to interact with neurotransmitters such as serotonin, dopamine, and norepinephrine, regulating their levels in the synaptic cleft. Option A) Cell membrane is incorrect because MAO is not typically found in the cell membrane but rather in the mitochondria. Option B) Plasma is also incorrect as MAO is an intracellular enzyme and is not typically found freely circulating in the blood plasma. Understanding the subcellular localization of enzymes like MAO is essential in pharmacology as it influences drug interactions, metabolism, and ultimately drug efficacy and side effects. This knowledge is crucial for healthcare professionals in selecting appropriate medications and understanding their mechanisms of action in treating various CNS disorders.

Correct Answer: C

Rationale: Introduction to the Pharmacology of CNS Drugs is a crucial subject in understanding the effects of various drugs on the central nervous system. In this context, the question regarding the specific impact of morphine on the small intestine is significant for understanding the drug's pharmacokinetics and potential side effects. The correct answer is C) Both (a) and (b) - Duodenum and Ileum. Morphine affects the small intestine, including both the duodenum and ileum. Morphine slows down peristalsis in the gastrointestinal tract, leading to constipation, a common side effect of opioid use. This effect is not limited to a specific part of the small intestine but rather affects the overall function. Option A) Duodenum and Option B) Ileum alone are incorrect because morphine's impact is not isolated to one specific part of the small intestine. It affects the entire organ due to its systemic effects on opioid receptors in the gastrointestinal tract. Option D) Does not affect the small intestine is also incorrect as morphine is well-known for its impact on the gastrointestinal system, particularly causing constipation through its actions in the small intestine. Educationally, understanding the effects of morphine on the small intestine provides insight into the broader impact of opioids on the body. It highlights the importance of monitoring and managing gastrointestinal side effects in patients receiving opioid therapy, contributing to safe and effective patient care. This knowledge is vital for healthcare professionals, especially those involved in pain management and pharmacology, to ensure the appropriate use of opioids and mitigate potential adverse effects.

Correct Answer: D

Rationale: The correct answer is D) All the above. Intravenous anaesthetic agents play a crucial role in preparing patients for anesthesia and reducing the amount of inhalation anesthetic needed during a procedure. Ultra-short acting barbiturates, such as thiopental, are useful for producing sedation before anesthesia induction. Benzodiazepines, like midazolam, also provide sedation and help reduce anxiety prior to anesthesia. Opioid analgesic anesthesia agents, such as fentanyl, provide pain relief and can complement the effects of other sedatives during anesthesia. Ultra-short acting barbiturates alone may not provide the full spectrum of effects needed for sedation and anesthesia, hence option A is incorrect. Option B, benzodiazepines, while useful for sedation, may not provide the full range of effects required for anesthesia induction. Option C, opioid analgesic anesthesia, focuses more on pain relief rather than sedation prior to anesthesia. Understanding the different classes of intravenous anaesthetic agents and their specific roles is crucial for healthcare professionals working in anesthesia. It ensures safe and effective patient care by tailoring sedation and anesthesia to individual patient needs, optimizing outcomes and minimizing risks associated with anesthesia administration.

Correct Answer: A

Rationale: In this question on inhalational anaesthetics, the correct statement is A) Enflurane is proconvulsant. This is true because enflurane, along with other halogenated inhalational anaesthetics like halothane and isoflurane, has been associated with lowering the seizure threshold, leading to a proconvulsant effect. Option B) Isoflurane is the inhalational agent of choice in IHD (Ischemic Heart Disease) is incorrect. While isoflurane is commonly used in cardiac anesthesia due to its myocardial depressant effects, it is not specifically the agent of choice in ischemic heart disease. Option C) Nitrous oxide is safe for pregnant women in the first trimester is incorrect. Nitrous oxide can diffuse rapidly across the placenta and has the potential to cause fetal hypoxia, making it contraindicated in pregnancy, especially in the first trimester. Option D) Halothane has a MAC value of 75% is incorrect. Halothane's MAC value is around 0.75%, not 75%. MAC (Minimum Alveolar Concentration) is a measure of anesthetic potency, with lower values indicating higher potency. In an educational context, understanding the pharmacological properties of inhalational anaesthetics is crucial for safe and effective patient care during anesthesia administration. Knowledge of their effects on various organ systems, including the central nervous system, helps healthcare providers make informed decisions and provide optimal care to patients undergoing anesthesia.

Correct Answer: D

Rationale: The correct answer is D) Amantadine has anti-Parkinsonian effects and is administered at a dose of 100mg bd. Rationale: Amantadine is an antiviral drug that also exhibits anti-Parkinsonian effects by increasing dopamine release and reducing dopamine reuptake. It is commonly used as an adjunct therapy in Parkinson's disease. The dosing regimen of 100mg twice daily is standard to achieve optimal therapeutic effects while minimizing side effects. Option A is incorrect because Bromocriptine is not the first-line drug for treating Parkinson's disease in psychotic patients. Dopamine agonists like pramipexole or ropinirole are often preferred. Option B is incorrect as only about 1-5% of a single dose of Levodopa enters the brain unaltered. The rest is metabolized peripherally, leading to side effects like nausea and dyskinesias. Option C is incorrect because while Selegiline is a MAO-B inhibitor used in Parkinson's disease, the dietary restrictions for tyramine-rich foods are associated with non-selective MAO inhibitors like phenelzine, not with Selegiline. In an educational context, understanding the pharmacology of CNS drugs in Parkinson's disease is crucial for healthcare professionals to provide optimal care for patients. Proper knowledge of drug mechanisms, dosing regimens, and potential side effects is essential for safe and effective treatment. This question highlights the importance of accurate drug information in managing Parkinson's disease.