Pyrazinamide
Mechanism :
Pyrazinamide, the pyrazine analogue of nicotinamide, is an antituberculosis agent. Pyrazinamide may be bacteriostatic or bactericidal against Mycobacterium tuberculosis depending on the concentration of the drug attained at the site of infection. The mechanism of action is unknown. In vitro and in vivo the drug is active only at a slightly acidic pH.
Indication :
Contraindications :
Contraindicated in known hypersensitivity, in severe hepatic damage, and acute gout. Monitor liver function before and during treatment. Baseline and regular monitoring of liver function is required in patients with known chronic liver disease and in those known to be hepatitis B or C antigen positive.
Dosing :
30-35 mg/kg/24 hours as single dose or in 2 divided doses PO (Max: 2 gm/day) for the first 2 months of the standard 6 month regimen.
Adverse Effect :
Hepatic cell function, fever, anorexia, malaise, liver tenderness, hepatomegaly and splenomegaly, active gout, sideroblastic anemia, arthralgias, anorexia, nausea and vomiting, dysuria, malaise, fever, urticaria, aggravation of peptic ulcer.
Interaction :
Probenecid and Sulfinpyrazone: Antagonises the effect of probenecid and sulfinpyrazone.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | Use 50–100% of dose |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | 50–100% dialysed. Dose as in GFR<10 mL/min or 25–30 mg/kg post dialysis |
| HDF/High flux | Dialysed. Dose as in GFR<10 mL/ min or 25–30 mg/kg post dialysis |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
Severe hepatic impairment: Contraindicated.