Classifications: antibiotic; antituberculosis agent; Therapeutic: antibiotic; antituberculosis
Pregnancy Category: C
500 mg tablets
Pyrazinoic acid amide, analog of nicotinamide.
Bacteriostatic against Mycobacterium tuberculosis. Not used as sole agent against TB infection.
Short-term therapy of advanced tuberculosis before surgery and to treat patients unresponsive to primary agents (e.g., isoniazid,
Severe liver damage, acute gout; pregnancy (category C).
History of gout or diabetes mellitus; impaired kidney function; alcoholism; history of peptic ulcer; acute intermittent
porphyria, and lactation.
Route & Dosage
Adult: PO 1535 mg/kg/d in 34 divided doses (max: 2 g/d)
Child: PO 2040 mg/kg/d divided q1224h (max: 2 g/d)
- Discontinue drug if hepatic reactions (jaundice, pruritus, icteric sclerae, yellow skin) or hyperuricemia with acute gout
(severe pain in great toe and other joints) occur.
- Store at 15°30° C (59°86° F) in tightly closed container.
Adverse Effects (≥1%)Body as a Whole: Active gout, arthralgia
, lymphadenopathy. Urogenital:
Difficulty in urination. CNS:
, decreased plasma
prothrombin. GI: Splenomegaly
, fatal hemoptysis,
aggravation of peptic ulcer
, hepatotoxicity, abnormal liver function tests. Metabolic: Rise in serum uric acid.
Diagnostic Test Interference
Pyrazinamide may produce a temporary decrease in 17-ketosteroids and an increase in protein-bound iodine.
Increase in liver toxicity
(including fatal hepatoxicity in when treating latent TB
) with rifampin.
Readily from GI tract. Peak:
2 h. Distribution:
Crosses bloodbrain barrier. Metabolism:
In liver. Elimination:
Slowly in urine. Half-Life:
Assessment & Drug Effect
- Observe and supervise closely. Patients should receive at least one other effective antituberculosis agent concurrently.
- Examine patients at regular intervals and question about possible signs of toxicity: Liver enlargement or tenderness, jaundice,
fever, anorexia, malaise, impaired vascular integrity (ecchymoses, petechiae, abnormal bleeding).
- Hepatic reactions appear to occur more frequently in patients receiving high doses.
- Lab tests: Obtain liver function tests (especially AST, ALT, serum bilirubin) prior to and at 24 wk intervals during
therapy. Blood uric acid determinations are advised before, during, and following therapy.
Patient & Family Education
- Report to physician onset of difficulty in voiding. Keep fluid intake at 2000 mL/d if possible.
- Monitor blood glucose (diabetics) for possible loss of glycemic control.