Okay, let's tackle this question. The user is asking which anti-tubercular therapy (ATT) drug causes hyperuricemia. First, I need to recall the drugs used in ATT and their side effects. The core concept here is the pharmacological knowledge of antitubercular drugs and their metabolic effects.

The correct answer is probably Pyrazinamide. I remember that Pyrazinamide is known to cause hyperuricemia. Why? Because it interferes with uric acid excretion by the kidneys. Let me check the mechanism. Pyrazinamide is metabolized to pyrazinoic acid, which may compete with uric acid for excretion in the renal tubules, leading to increased serum uric acid levels. Alternatively, it might inhibit urate transporters, reducing uric acid clearance.

Now, looking at the other options. I need to think about other ATT drugs. Isoniazid? Its main side effect is hepatotoxicity, and it can cause peripheral neuropathy. Ethambutol's main issue is optic neuritis. Rifampin is a strong inducer of liver enzymes and causes hepatotoxicity. So none of these are associated with hyperuricemia. Streptomycin? It's an aminoglycoside, so nephrotoxicity and ototoxicity are the main concerns. No hyperuricemia there.

Wait, is there another drug? Maybe Thiacetazone? No, that's less commonly used and more associated with hepatotoxicity. So Pyrazinamide is the key here. The clinical pearl would be to remember Pyrazinamide's effect on uric acid levels, which is a common exam question. Also, patients on Pyrazinamide should be monitored for gout symptoms, and allopurinol might be needed if hyperuricemia is present. That's the high-yield fact.

**Core Concept**
Hyperuricemia is a metabolic side effect of certain anti-tubercular drugs, particularly those affecting uric acid excretion. Pyrazinamide, a first-line ATT drug, is the most common culprit due to its interference with renal uric acid handling.

**Why the Correct Answer is Right**
Pyrazinamide is metabolized to pyrazinoic acid, which competitively inhibits uric acid excretion in the proximal renal tubules. This leads to reduced uric acid clearance and elevated serum levels. It is a classic high-yield side effect in pharmacology and clinical medicine, often requiring monitoring for gout in susceptible patients.

**Why Each Wrong Option is Incorrect**
**Option A:** Isoniazid primarily causes hepatotoxicity and peripheral neuropathy; no role in uric acid metabolism.
**Option B:** Rifampin induces hepatic cytochrome P450 enzymes, leading to drug interactions and hepatotoxicity, not hyperuricemia.
**Option C:** Ethambutol’s main adverse effect is optic neuritis; it does not affect uric acid levels.

**Clinical Pearl / High-Yield Fact**
Pyrazinamide is the only first-line ATT drug associated with hyperuricemia. Remember **"P for Pyrazinamide and Pain of Gout"** to recall its uric acid-elevating effect. Monitor serum uric acid in patients on this drug, especially those

✓ Correct Answer: B. Pyrazinamide