Adverse effects associated with the interferons include:

Correct Answer: D

Rationale: Lymphopenia (D) is an adverse effect of interferons, like interferon alfa, due to bone marrow suppression, reducing lymphocyte counts, common in chronic hepatitis or cancer therapy. Hypocalcemia (A) isn't typical; interferons more often cause flu-like symptoms. Inhibition of spermatogenesis (B) occurs, reflecting gonadal toxicity, but D is highlighted. Renal tubular acidosis (C) isn't a primary effect; nephrotoxicity is rare. Flu-like symptoms (original E) are frequent, including fever and fatigue. Interferons' immunomodulatory and antiproliferative actions explain these effects, activating immune responses while suppressing cell proliferation, necessitating monitoring during prolonged use.

Correct Answer: A

Rationale: Pretreatment hydration is mandatory in cisplatin therapy (A), reducing nephrotoxicity by diluting the drug in renal tubules, critical for its safe use in testicular and lung cancers. Dexamethasone and 5HT3 antagonists (B) reduce its high emetogenicity effectively. Visual disturbances (C) are rare; ototoxicity is more common. Magnesium supplements (D) are given for hypomagnesemia from renal loss. Nephrotoxicity is dose-limiting (original E). Cisplatin's DNA cross-linking kills cancer cells, but its renal and auditory toxicity, linked to platinum accumulation, demands aggressive hydration and electrolyte management.

Correct Answer: D

Rationale: Hepatic metabolism and renal excretion are the two most important mechanisms involved (D) in terminating drug action. The liver metabolizes drugs into inactive or more excretable forms, while the kidneys filter and excrete them, as seen with many drugs like penicillin. Option A is incorrect because redistribution (e.g., thiopental moving from brain to fat) can terminate action without excretion. Option B is false; metabolism can produce lipid-soluble metabolites (e.g., morphine to morphine-6-glucuronide). Option C is wrong as some metabolites retain activity (e.g., diazepam to nordazepam). Option E (original) about distribution is a mechanism but less dominant than metabolism and excretion. These processes ensure drug clearance, balancing efficacy and toxicity, with liver and kidney function critical to dosing adjustments in disease states.

Correct Answer: A

Rationale: A pharmacological antagonist (A) best describes a drug that blocks epinephrine's action by occupying its receptors (e.g., beta-blockers like propranolol) without activation, competitively inhibiting the agonist. Partial agonists (B) activate receptors submaximally (e.g., pindolol). Physiological antagonists (C) counteract via different systems (e.g., histamine vs. epinephrine). Chemical antagonists (D) bind the agonist itself (e.g., chelators), not receptors. Noncompetitive antagonists (original E) bind irreversibly, reducing receptor availability. Pharmacological antagonism, central to receptor theory, relies on affinity without efficacy, reversing or preventing epinephrine's effects (e.g., tachycardia), a key concept in managing adrenergic overactivity in conditions like hypertension.

Correct Answer: B

Rationale: The dominant lethal test is a test of mutagenicity (B), detecting mutations in male germ cells causing fetal death or abnormalities post-mating, indicating DNA damage (e.g., from alkylating agents). Teratogenicity (A) tests developmental defects from maternal exposure during pregnancy, not paternal. Carcinogenicity (C) assesses tumor formation, requiring long-term studies. Option D is incorrect as it's specific to mutagenesis. Option E (original) is also false. Used in toxicology, this assay identifies genotoxic potential, critical for assessing reproductive risks of chemicals, though it doesn't predict teratogenesis or cancer directly.