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(peer a ZIN a mide)

Index Terms

  • Pyrazinoic Acid Amide

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Generic: 500 mg

Pharmacologic Category

  • Antitubercular Agent


Converted to pyrazinoic acid in susceptible strains of Mycobacterium which lowers the pH of the environment; exact mechanism of action has not been elucidated


Well absorbed


Widely into body tissues and fluids including liver, lung, and CSF

Relative diffusion from blood into CSF: Adequate with or without inflammation (exceeds usual MICs)

CSF:blood level ratio: Inflamed meninges: 100%




Urine (4% as unchanged drug)

Time to Peak

Serum: Within 2 hours

Half-Life Elimination

9 to 10 hours, prolonged with reduced renal or hepatic function

Protein Binding


Use: Labeled Indications

Adjunctive treatment of tuberculosis in combination with other antituberculosis agents


Hypersensitivity to pyrazinamide or any component of the formulation; acute gout; severe hepatic damage

Dosing: Adult

Tuberculosis treatment: Oral: Note: Used as part of a multidrug regimen. Treatment regimens consist of an initial 2-month phase, followed by a continuation phase of 4 or 7 additional months; pyrazinamide is administered in the initial phase of treatment.

Suggested dosing based on lean body weight (Blumberg, 2003; CDC, 2003):

Daily therapy:

40-55 kg: 1000 mg

56-75 kg: 1500 mg

76-90 kg: 2000 mg (maximum dose regardless of weight)

Twice weekly directly observed therapy (DOT):

40-55 kg: 2000 mg

56-75 kg: 3000 mg

76-90 kg: 4000 mg (maximum dose regardless of weight)

Three times/week DOT:

40-55 kg: 1500 mg

56-75 kg: 2500 mg

76-90 kg: 3000 mg (maximum dose regardless of weight)

Dosing: Pediatric

Tuberculosis treatment: Oral: Note: Used as part of a multidrug regimen. Treatment regimens consist of an initial 2-month phase, followed by a continuation phase of 4 or 7 additional months; pyrazinamide is administered in the initial phase of treatment.

HIV negative (CDC, 2003):

Daily therapy: 15-30 mg/kg/day (maximum: 2 g/day)

Twice weekly directly observed therapy (DOT): 50 mg/kg/dose (maximum: 2 g/dose)

HIV-exposed/-infected: Daily therapy: 20-40 mg/kg/dose once daily (maximum: 2 g/day) (CDC, 2009)

Dosing: Renal Impairment

Adults: CrCl <30 mL/minute or receiving hemodialysis: Treatment of TB: 25-35 mg/kg/dose 3 times per week administered after dialysis (Blumberg, 2003; CDC, 2003)

Dosing: Hepatic Impairment

No dosage adjustment provided in manufacturer’s labeling. Use is contraindicated in cases of severe hepatic impairment.

Extemporaneously Prepared

A 100 mg/mL oral suspension may be made with tablets. Crush two-hundred pyrazinamide 500 mg tablets and mix with a suspension containing 500 mL methylcellulose 1% and 500 mL simple syrup. Add to this a suspension containing one-hundred forty crushed pyrazinamide tablets in 350 mL methylcellulose 1% and 350 mL simple syrup to make 1.7 L suspension. Label "shake well" and "refrigerate". Stable for 60 days refrigerated (preferred) and 45 days at room temperature.

Nahata MC, Morosco RS, and Peritre SP, “Stability of Pyrazinamide in Two Suspensions,” Am J Health Syst Pharm, 1995, 52(14):1558-60.7552903


Store at controlled room temperature of 15°C to 30°C (59°F to 86°F).

Drug Interactions

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Benzbromarone: Pyrazinamide may diminish the therapeutic effect of Benzbromarone. Monitor therapy

Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Avoid combination

CycloSPORINE (Systemic): Pyrazinamide may decrease the serum concentration of CycloSPORINE (Systemic). Monitor therapy

Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy

RifAMPin: Pyrazinamide may enhance the hepatotoxic effect of RifAMPin. Severe (even fatal) liver injury has been reported in patients receiving these 2 drugs as a 2-month treatment regimen for latent TB infection. Consider therapy modification

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Test Interactions

Reacts with Acetest® and Ketostix® to produce pinkish-brown color

Adverse Reactions

1% to 10%:

Central nervous system: Malaise

Gastrointestinal: Anorexia, nausea, vomiting

Neuromuscular & skeletal: Arthralgia, myalgia

<1% (Limited to important or life-threatening): Acne vulgaris, acquired blood coagulation disorder (anticoagulant effect), angioedema (rare), dysuria, fever, gout, hepatotoxicity, interstitial nephritis, porphyria, pruritus, sideroblastic anemia, skin photosensitivity, skin rash, thrombocytopenia, urticaria


Concerns related to adverse effects:

• Hepatotoxicity: Dose-related hepatotoxicity ranging from transient ALT/AST elevations to jaundice, hepatitis and/or liver atrophy (rare) has occurred.

Disease-related concerns:

• Alcoholism: Due to concerns for preexisting hepatic dysfunction, use with caution in patients with a history of alcoholism (even if ethanol consumption is discontinued during therapy).

• Diabetes: Use with caution in patients with diabetes mellitus.

• Gout: May inhibit uric acid excretion; acute gouty attacks have been reported. Use with caution in patients with chronic gout; contraindicated with acute gout.

• Porphyria: Use with caution in patients with porphyria.

• Renal impairment: Use with caution in patients with renal failure.

Concurrent drug therapy issues:

• Hepatotoxic agents: Use with caution in patients receiving concurrent medications associated with hepatotoxicity (particularly with rifampin). The 2-month rifampin-pyrazinamide regimen for the treatment of latent tuberculosis infection (LTBI) has been associated with severe and fatal liver injuries; incidence increased with pyrazinamide doses >30 mg/kg/day. The Infectious Diseases Society of America and Centers for Disease Control and Prevention recommend that the 2-month rifampin-pyrazinamide regimen should not generally be used in patients with LTBI.

Monitoring Parameters

Periodic liver function tests, serum uric acid, sputum culture, chest x-ray 2-3 months into treatment and at completion

Pregnancy Risk Factor


Pregnancy Considerations

Teratogenic effects have not been observed in animal reproduction studies. Due to the risk of tuberculosis to the fetus, treatment is recommended when the probability of maternal disease is moderate to high. Although not recommended as the initial treatment regimen, the use of pyrazinamide during pregnancy is recommended by The World Health Organization (Blumberg, 2003).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Have patient report immediately to prescriber signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), severe bone pain, severe joint pain, severe muscle pain, urinary retention, or change in amount of urine passed (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.