Following statement is correct about criteria for neurotransmitter

Correct Answer: D

Rationale: In pharmacology of CNS drugs, understanding the criteria for neurotransmitters is crucial for grasping how different drugs interact with the nervous system. The correct answer is D) All of the above because neurotransmitters must meet all three criteria to effectively transmit signals between neurons. A) "Must be present in presynaptic terminals": This is important because neurotransmitters are stored in vesicles within the presynaptic terminal and are released upon stimulation. B) "Must be released with presynaptic activity": Neurotransmitters are released in response to an action potential reaching the presynaptic terminal, allowing for communication between neurons. C) "Must mimic effects of presynaptic stimulation": Neurotransmitters bind to receptors on the postsynaptic neuron, leading to a physiological response that mimics the effects of presynaptic stimulation. Educationally, understanding these criteria helps in comprehending how drugs that target neurotransmitter systems can modulate neuronal signaling. It also aids in predicting how altering neurotransmitter levels or receptor activity can impact brain function and behavior, which is crucial in pharmacological interventions for CNS disorders.

Correct Answer: D

Rationale: In the context of pharmacology of CNS drugs, understanding how different medications can affect seizure activity in epileptic patients is crucial. In this question, the correct answer is D) L-Dopa, which may increase seizure activity in epileptic patients. L-Dopa is a precursor to dopamine and is used in the treatment of Parkinson's disease. However, in epileptic patients, it can lower the seizure threshold, leading to an increased risk of seizures. This occurs due to the way L-Dopa interacts with neurotransmitters in the brain, potentially triggering abnormal electrical activity that can manifest as seizures. Now, let's discuss why the other options are incorrect: A) Ethotoin and B) Phenobarbital are antiepileptic drugs commonly used to control seizures in epileptic patients. They work by stabilizing neuronal membranes and reducing excessive electrical activity in the brain, thus decreasing the likelihood of seizures. C) Trihexyphenidyl is an anticholinergic medication primarily used to treat symptoms of Parkinson's disease and drug-induced extrapyramidal symptoms. While it does not directly increase seizure activity, it is not typically associated with seizure control either. Educationally, this question highlights the importance of understanding how different medications can have varying effects on seizure activity in epileptic patients. It reinforces the need for healthcare providers to consider a patient's complete medication regimen and medical history when prescribing drugs that may impact seizure risk. This knowledge is essential for safe and effective pharmacological management of patients with epilepsy.

Correct Answer: D

Rationale: In pharmacology of CNS drugs, understanding the therapeutic applications of neurotransmitters like acetylcholine is crucial. Option D, "Both B and C are correct," is the right choice because acetylcholine's effects are indeed transient, and it produces widespread actions affecting many organs. Acetylcholine's transient effects limit its therapeutic use as sustained actions are often required for effective treatment. Additionally, its widespread actions affecting multiple organs can lead to off-target effects, making it challenging to use acetylcholine as a specific therapeutic agent. Option A, "None of its actions are beneficial," is incorrect because acetylcholine does have physiological functions that are essential for normal bodily functions. Option B alone is not sufficient to explain why acetylcholine has no therapeutic application, as transient effects alone may not preclude a substance from being therapeutically useful. Educationally, this question highlights the importance of understanding the pharmacological properties of neurotransmitters in determining their therapeutic potential. It emphasizes the need for drugs with specific, sustained effects in the treatment of CNS disorders, rather than substances with transient and widespread actions. Students benefit from grasping these concepts to make informed decisions in clinical practice.

Correct Answer: C

Rationale: In the context of pharmacology of CNS drugs, understanding the use of diuretics in conditions like acute congestive glaucoma is crucial. In this scenario, the correct diuretic is Mannitol (Option C). Mannitol is an osmotic diuretic that works by increasing the osmotic pressure of glomerular filtrate, leading to increased urine output. Mannitol is particularly effective in acute congestive glaucoma because it rapidly reduces intraocular pressure by drawing fluid out of the eye tissues. This mechanism of action helps to quickly relieve the pressure within the eye, which is essential in managing acute cases of glaucoma. Now, let's analyze why the other options are incorrect: A) Indapamide and D) Furosemide are loop diuretics that primarily act on the kidneys to promote the excretion of water and electrolytes. While they are useful in conditions like heart failure and hypertension, they are not the diuretics of choice for acute congestive glaucoma. B) Amiloride is a potassium-sparing diuretic that works by reducing the amount of potassium excreted in the urine. It is not typically used in the management of acute congestive glaucoma due to its mechanism of action. In an educational context, this question highlights the importance of understanding the specific mechanisms of action and indications for different diuretics. It also underscores the significance of tailoring drug therapy to the specific needs of a patient based on the condition being treated. This knowledge is essential for healthcare professionals, especially pharmacists and physicians, to make informed decisions in clinical practice.

Correct Answer: A

Rationale: In the context of pharmacology of CNS drugs, understanding the properties of surface anesthetics is crucial for safe and effective clinical practice. In this question, the correct answer is A) Procaine, which is a poor surface anesthetic. Procaine has a slower onset of action and shorter duration compared to other options like Lidocaine, Tetracaine, and Benoxinate. This is due to its lower potency and shorter duration of action, making it less effective for surface anesthesia. Lidocaine, Tetracaine, and Benoxinate are all more potent and longer-acting surface anesthetics compared to Procaine. Lidocaine, for example, is commonly used for various procedures due to its rapid onset and intermediate duration of action. Tetracaine is a long-acting surface anesthetic often used in ophthalmology. Benoxinate is a rapid-acting ophthalmic anesthetic. Educationally, understanding the differences in onset, potency, and duration of action among surface anesthetics is essential for selecting the most appropriate agent for specific clinical scenarios. This knowledge helps healthcare providers optimize patient care by ensuring effective pain management while minimizing risks associated with anesthesia.