1. What is the mechanism of action of angiotensin-converting enzyme (ACE) inhibitors? How do they affect blood pressure and renal function? Answer: ACE inhibitors block the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor that also stimulates aldosterone secretion. By reducing angiotensin II levels, ACE inhibitors lower blood pressure and decrease sodium and water retention. They also prevent the degradation of bradykinin, a vasodilator that enhances renal blood flow and natriuresis. 2. What are the indications and contraindications for using nonsteroidal antiinflammatory drugs (NSAIDs)? What are the most common adverse effects and drug interactions of NSAIDs? Answer: NSAIDs are indicated for the treatment of pain, inflammation, fever, dysmenorrhea, osteoarthritis, rheumatoid arthritis, gout, and other conditions. They are contraindicated in patients with hypersensitivity, peptic ulcer disease, bleeding disorders, renal impairment, heart failure, or aspirininduced asthma. The most common adverse effects of NSAIDs are gastrointestinal irritation, ulceration, bleeding, nephrotoxicity, hepatotoxicity, and increased risk of cardiovascular events. NSAIDs can interact with anticoagulants, corticosteroids, lithium, methotrexate, diuretics, antihypertensives, and other drugs. 3. What are the differences between selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs)? How do they affect mood and cognition? Answer: SSRIs and SNRIs are both antidepressants that inhibit the reuptake of serotonin in the synaptic cleft, increasing its availability and enhancing its neurotransmission. SNRIs also inhibit the reuptake of norepinephrine, another neurotransmitter involved in mood regulation. Both SSRIs and SNRIs can improve mood, anxiety, sleep, appetite, and energy levels in patients with depression and other psychiatric disorders. They can also have positive effects on cognition, such as memory, attention, and executive function. 4. What are the pharmacokinetic properties of warfarin? How is its dosage determined and monitored? What are the factors that can alter its efficacy and safety?