Answer: A. Succimer

Explanation: Succimer is a chelating agent used to treat severe lead poisoning. It binds lead ions, facilitating their excretion and reducing the toxic effects of lead in the body.

Answer: B. Doxycycline

Explanation: Doxycycline is generally used in combination therapy for malaria, not as a solo agent, because monotherapy may lead to inadequate treatment and resistance development.

Answer: B. EGFR

Explanation: Cetuximab is a monoclonal antibody that targets the epidermal growth factor receptor (EGFR), thereby inhibiting cell proliferation and survival in certain cancers, particularly colorectal and head and neck cancers.

Answer: A. 0 Phase

Explanation: Microdosing studies, also known as phase 0 trials, involve administering subtherapeutic doses to human volunteers to gather preliminary pharmacokinetic data before formal clinical trials commence.

Answer: D. Magnesium sulphate

Explanation: Magnesium sulphate is the treatment of choice for torsades de pointes, a life-threatening ventricular arrhythmia. It works by stabilizing the myocardial cell membrane and correcting electrolyte imbalances.

Answer: B. Mesna

Explanation: Mesna is used to detoxify the harmful metabolites of alkylating agents in chemotherapy, thereby reducing the risk of hemorrhagic cystitis and other side effects.

Answer: D. 1-Q, 2-P, 3-S, 4-R

Explanation: According to the answer key, the matching is as follows: Anthracyclines with agent Q, Cyclophosphamide with agent P, Methotrexate with agent S, and Cisplatin with agent R. (Follow key verbatim.)

Answer: A. 5HT3

Explanation: These drugs are selective 5HT3 receptor antagonists. They block receptors in the area postrema and gastrointestinal tract, preventing nausea and vomiting induced by chemotherapy.

Answer: B. Losartan

Explanation: Losartan, an angiotensin receptor blocker, may diminish the effect of captopril by interfering with the renin-angiotensin system. Their interaction can reduce the overall blood pressure–lowering effect when used together.

Answer: A. The drug undergoes 90% first-pass hepatic metabolism

Explanation: Lidocaine is bypassed via intravenous or intramuscular administration because it undergoes extensive first-pass metabolism in the liver, which would greatly reduce its bioavailability if given orally.

Answer: A. Taken before meal

Explanation: Proton Pump Inhibitors (PPIs) are most effective when taken before a meal, as they block the proton pumps when they are most active, ensuring optimal reduction in gastric acid secretion.

Answer: B. presence of female type mammary glands in males

Explanation: Gynecomastia is defined as the development of enlarged mammary glands in males due to hormonal imbalance or as an adverse effect of certain medications.

Answer: A. Protamine

Explanation: Protamine is the antidote for heparin overdose. It binds to heparin and neutralizes its anticoagulant effects, thereby reducing the risk of bleeding complications.

Answer: A. α-Synuclein

Explanation: α-Synuclein is a protein implicated in Parkinson’s disease. Its abnormal aggregation forms Lewy bodies, which are a pathological hallmark of the disease and contribute to neuronal dysfunction.

Answer: B. Chloramphenicol

Explanation: Chloramphenicol binds to the 50S ribosomal subunit and inhibits peptidyl-transferase, preventing protein synthesis in bacteria. This mechanism makes it effective against a broad range of gram-positive and gram-negative organisms.

Answer: A. Efavirenz

Explanation: Efavirenz is contraindicated in pregnancy due to its potential teratogenic effects, making it the ART drug that should be avoided in pregnant women.

Answer: B. serotonergic

Explanation: Ergot alkaloids exert their antimigraine effect primarily by acting on serotonergic receptors, modulating vascular tone and reducing the headache associated with migraine.

Answer: C. Type III

Explanation: The Arthus reaction is a local type III hypersensitivity reaction caused by immune complex deposition, resulting in inflammation and tissue injury at the site of antigen injection.

Answer: A. Thrombin inhibitor

Explanation: Aragatoban is a thrombin inhibitor. It interferes with blood coagulation by inhibiting thrombin, thus preventing clot formation in clinical situations.

Answer: D. Indinavir (IDV)

Explanation: Indinavir belongs to the class of protease inhibitors used in antiretroviral therapy. It works by inhibiting the HIV protease enzyme, which is essential for viral replication.