Pyrazinamide

How Medicare covers it

Part D (forms used at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Pyrazinamide is indicated for the initial treatment of active tuberculosis in adults and children when combined with other antituberculous agents. (The CDC recommendation for drug-susceptible disease cited in the label is a six-month regimen: isoniazid, rifampin, and pyrazinamide given for 2 months, followed by isoniazid and rifampin for 4 months.) It is also indicated after treatment failure with other primary drugs in any form of active tuberculosis. Pyrazinamide should only be used in conjunction with other effective antituberculous agents.

What it is for, in depth

Pyrazinamide is one of the core drugs for tuberculosis (TB), the bacterial infection caused by Mycobacterium tuberculosis, usually of the lungs. Its place in the treatment path is specific: it is part of the first (intensive) phase of therapy, because it works against TB bacteria in the slightly acidic pockets where other drugs work less well — the contribution that allowed modern TB treatment to be shortened to 6 months. For drug-susceptible TB the label carries the CDC regimen: isoniazid, rifampin, and pyrazinamide for the first 2 months, then isoniazid and rifampin alone for 4 more months. It is also used after treatment failure with other primary drugs, in any form of active TB, and it frequently remains an important component of the individualized regimens built for drug-resistant TB. It must never be used alone: TB bacteria become resistant when exposed to a single drug, so pyrazinamide is only ever one part of a combination. The people who take it are adults and children with active TB, treated under public-health or specialist supervision, often with directly observed therapy. The only form is the 500 mg tablet in this package, dosed by body weight once a day.

How it works

Pyrazinamide may be bacteriostatic or bactericidal against Mycobacterium tuberculosis depending on the concentration of the drug attained at the site of infection; it is active only at a slightly acidic pH. The label states the mechanism of action is unknown. Pyrazinamide is hydrolyzed in the liver to its major active metabolite, pyrazinoic acid.

How it is taken

Tablets of 500 mg by mouth, always administered with other effective antituberculous drugs. The usual dose is 15 to 30 mg/kg once daily (the CDC recommendations do not exceed 2 g per day on a daily regimen, and 3 grams per day should not be exceeded); it is administered for the initial 2 months of a 6-month or longer treatment regimen for drug-susceptible patients. Alternatively, a twice-weekly dosing regimen (50 to 70 mg/kg twice weekly, based on lean body weight) has been developed to promote patient compliance. Patients with drug-resistant disease are treated with individualized regimens, in which pyrazinamide frequently is an important component, and patients with concomitant HIV infection may require longer courses of therapy.

Common side effects

The principal adverse effect is a hepatic reaction (see serious warnings); hepatotoxicity appears to be dose related and may appear at any time during therapy. Gastrointestinal disturbances including nausea, vomiting, and anorexia have been reported. Mild arthralgia (joint pain) and myalgia (muscle pain) have been reported frequently. Hypersensitivity reactions including rashes, urticaria, and pruritus have been reported. Pyrazinamide inhibits renal excretion of urates, frequently resulting in hyperuricemia, which is usually asymptomatic.

Serious warnings

Patients started on pyrazinamide should have baseline serum uric acid and liver function determinations, and those with preexisting liver disease or at increased risk for drug-related hepatitis (e.g., alcohol abusers) should be followed closely. Pyrazinamide should be discontinued and not be resumed if signs of hepatocellular damage or hyperuricemia accompanied by an acute gouty arthritis appear. Pyrazinamide is contraindicated in persons with severe hepatic damage, in persons who have shown hypersensitivity to it, and in persons with acute gout. Rarely reported effects include thrombocytopenia and sideroblastic anemia, porphyria, dysuria, and interstitial nephritis. Patients should be instructed to notify their physicians promptly of fever, loss of appetite, malaise, nausea and vomiting, darkened urine, yellowish discoloration of the skin and eyes, or pain or swelling of the joints.

Who should be careful

Persons with severe hepatic damage, hypersensitivity to pyrazinamide, or acute gout must not take it (contraindicated). Use with caution in patients with a history of diabetes mellitus, as management may be more difficult, and monitor patients with preexisting liver disease or increased risk of drug-related hepatitis closely. Baseline liver function studies (especially ALT and AST) and uric acid levels should be determined prior to therapy, with appropriate laboratory testing at periodic intervals and if any clinical signs or symptoms occur. Compliance with the full course of therapy must be emphasized and doses must not be missed.

Major interactions

The label lists a drug/laboratory test interaction: pyrazinamide has been reported to interfere with ACETEST and KETOSTIX urine tests to produce a pink-brown color. No drug-drug interactions are named in this label.

Why it is in its tier

In the CMS 2027 formulary aggregation, the most common (modal) tier for pyrazinamide is Tier 4 — the tier it sits on in 76.78% of the plans that list it — and every plan in the file lists the 500 mg tablet. Tier 4 is the non-preferred tier in the standard framework, which usually means higher coinsurance rather than a small flat copay. That is an unusual placement for an old generic tablet, and the data show it is a placement pattern, not a cost effect: pyrazinamide's CMS dashboard average spending was only $446.69 per beneficiary in 2024 (a program average, not a reader's copay), the lowest in this batch, and it is used by a small population (1,344 beneficiaries in 2024). Most formularies simply file this little-used TB drug as non-preferred rather than on a preferred generic tier. A tier exception can be requested on any plan, TB treatment is also frequently supplied through public-health programs, and individual plans vary — the tier on a reader's own plan list is what counts.

Sources

• PYRAZINAMIDE tablet — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus — Pyrazinamide

What official patient guides say

Pyrazinamide is a tablet taken by mouth, always with the other tuberculosis medicines in your treatment plan. It is usually taken once a day, at the same time each day, or in larger doses twice a week, and it may be taken with or without food. Take it exactly as directed — do not take more, less, or more often than your doctor prescribed. If you forget a dose, take it as soon as you remember it, unless it is almost time for the next dose — then skip the missed dose and take only your regular dose. Do not take a double dose to make up for a missed one. Keep all appointments with your doctor and the laboratory, since your doctor will order tests to check how you are responding. Keep it in the container it came in, tightly closed and out of reach of children, and store it at room temperature away from extra heat and moisture, not in the bathroom.

Source: MedlinePlus — Pyrazinamide

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is 1.31424 per unit (PYRAZINAMIDE 500 MG TABLET) — about nan for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-08

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 5,495 list Pyrazinamide — 100% of plans. Most of those plans put it on Tier 4: 4,219 plans, 76.8% of the plans that list it. Other plans place it on Tier 2 (697 plans), Tier 1 (365 plans) or Tier 3 (214 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 4; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 4; Aetna Medicare Value Plus (PPO) puts it on Tier 4. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan';s deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.