Indicate the antiparkinsonism drug which should be avoided in patients with glaucoma:

Correct Answer: D

Rationale: The correct answer is D: Trihexyphenidyl. Trihexyphenidyl is an anticholinergic drug that can worsen glaucoma by causing pupil dilation, leading to increased intraocular pressure. This can exacerbate the condition and potentially cause vision problems. Selegiline (A) is a monoamine oxidase inhibitor used in Parkinson's disease but does not affect glaucoma. Levodopa (B) is a gold standard treatment for Parkinson's and does not directly impact glaucoma. Bromocriptine (C) is a dopamine agonist used in Parkinson's but does not have a significant effect on glaucoma. Thus, the correct choice to avoid in patients with glaucoma is Trihexyphenidyl due to its potential to worsen the condition.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Orthostatic hypotension can occur due to various mechanisms, such as central action of phenothiazines causing vasodilation, inhibition of norepinephrine uptake leading to decreased vasoconstriction, and alpha adrenoreceptor blockade reducing sympathetic response. Each of these factors can contribute to a drop in blood pressure upon standing. Choices A, B, and C all play a role in the development of orthostatic hypotension, making option D the correct comprehensive answer.

Correct Answer: D

Rationale: The correct answer is D: All of the above. Highly selective serotonin reuptake inhibitors (SSRIs) target the reuptake of serotonin specifically. Sertraline, paroxetine, and fluoxetine are all SSRIs. They do not significantly affect other neurotransmitters, making them highly selective. Therefore, all three choices are correct as they are all examples of highly selective serotonin reuptake inhibitors.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Flumazenil is a competitive antagonist of BZ receptors by binding and blocking their activity. 2. Buspirone is a partial agonist at serotonin receptors, not BZ receptors. 3. Picrotoxin is a non-competitive antagonist at GABA receptors, not BZ receptors. 4. Diazepam is a positive allosteric modulator at BZ receptors, not a competitive antagonist. Summary: Flumazenil is the correct answer as it specifically targets BZ receptors as a competitive antagonist, while the other options act on different receptors or in different ways.

Correct Answer: C

Rationale: Certainly! Nitrous oxide is the correct answer as it is the only gas anesthetic listed. It is commonly used in dentistry and minor surgeries due to its anesthetic properties. Halothane, isoflurane, and desflurane are all liquid inhalants, not gas anesthetics. Nitrous oxide stands out as the only gas option among the choices.