Most phenothiazine derivatives have:

Correct Answer: D

Rationale: Phenothiazine derivatives like chlorpromazine possess antihistaminic, anticholinergic, and antidopaminergic activities. These properties make them effective in treating various conditions like schizophrenia. Antihistaminic activity helps with sedation, anticholinergic activity reduces side effects like tremors, and antidopaminergic activity helps manage psychotic symptoms. Therefore, the correct answer is D. Choices A, B, and C are incorrect because phenothiazines typically exhibit a combination of all three activities, not just one.

Correct Answer: D

Rationale: The correct answer is D, all of the above. Anxiolytic dosage reduction is recommended in patients taking cimetidine due to potential drug interactions. In patients with hepatic dysfunction, reduced metabolism can lead to increased drug levels. Elderly patients may be more sensitive to anxiolytics due to age-related changes in metabolism and increased risk of adverse effects. Therefore, all three factors (cimetidine use, hepatic dysfunction, and age) can influence anxiolytic dosing, making D the correct choice.

Correct Answer: A

Rationale: Rationale: Inhaled anesthetics and intravenous agents with general anesthetic properties directly activate GABAA receptors. GABAA receptors are inhibitory neurotransmitter receptors in the brain. Activation of GABAA receptors leads to hyperpolarization of the neuron, resulting in decreased neuronal excitability and ultimately producing the anesthetic effect. Summary: A: Direct activation of GABAA receptors is correct as it aligns with the mechanism of action of general anesthetics. B: Facilitating GABA action but not directly acting on GABAA receptors is incorrect as direct activation is necessary for the anesthetic effect. C: Reducing glutamatergic neurotransmission is incorrect as it is not the primary mechanism of action for general anesthetics. D: Increasing the duration of opening of nicotine-activated potassium channels is incorrect as it is not related to the mechanism of action of general anesthetics.

Correct Answer: B

Rationale: The correct answer is B: Zafirlucast, a leucotriene receptor antagonist. Leukotrienes are inflammatory mediators in asthma. Zafirlucast specifically blocks the action of leukotrienes by binding to their receptors, reducing inflammation and bronchoconstriction. Sodium cromoglycate (A) is a mast cell stabilizer, not a leukotriene receptor antagonist. Zileutin (C) inhibits 5-lipoxygenase, an enzyme involved in leukotriene synthesis. Triamcinolone (D) is a corticosteroid that acts through a different anti-inflammatory mechanism.

Correct Answer: C

Rationale: The correct answer is C: Activation of the antifibrinolytic system. This system is involved in clot dissolution, not bleeding control. Platelet adhesion, release, and triggering the coagulation process are essential physiological reactions that help control bleeding by forming a stable blood clot. Platelet adhesion allows platelets to stick to the site of injury, platelet release releases factors that promote clot formation, and triggering the coagulation process leads to the formation of fibrin strands that strengthen the clot. Therefore, choices A, B, and D are involved in the control of bleeding, while choice C is not.