Pyrazinamide Pharmacology


About Pyrazinamide
Niacinamide derivative, Antitubercular.
Mechanism of Action of Pyrazinamide
Pyrazinamide is a bactericidal or bacteriostatic drug depending on the drug concentration at the infection site and the susceptibility of organism. Pyrazinamide is a prodrug and it undergoes hydrolysis and forms the active metabolite Pyrazinoic acid. It disrupted membrane energetic and inhibited membrane transport function at acid pH in Mycobacterium tuberculosis. The anti-mycobacterial activity appears to depend on conversion of the drug to Pyrazinoic acid. Susceptible strains of M. tuberculosis produce pyrazinamidase, an enzyme that deaminates Pyrazinamide to Pyrazinoic acid, and the vitro susceptibility of a given strain of the organism appears to correspond to its pyrazinamidase activity. Experimental evidence suggests that Pyrazinamide diffuses into M. tuberculosis in a passive manner, is converted into Pyrazinoic acid by pyrazinamidase and because of an inefficient efflux system, accumulates in huge amounts in the bacterial cytoplasm. The accumulation of Pyrazinoic acid lowers the intracellular pH to a suboptimal level that is likely to inactivate a vital target enzyme such as fatty acid synthase.
Pharmacokinets of Pyrazinamide
Absorption: It is well absorbed after oral administration.Distribution: It is very widely distributed mainly to tissues and fluids. It has good penetration in CSF. Only 50 % is distributed in protein bound form.Metabolism: It undergoes hydrolysis in the liver.Excretion: It is excreted mainly in the urine
Onset of Action for Pyrazinamide
30 - 60 minutes
Duration of Action for Pyrazinamide
12-16 hours.
Half Life of Pyrazinamide
9 - 10 hours
Side Effects of Pyrazinamide
1. Nausea
2. Vomiting
3. Anorexia
4. Rash
5. Urticaria
6. Malaise
7. Arthralgia
8. Myalgia
9. Pruritis
10. Photosensitivity
11. Fever
12. Dysuria
13. Porphyria
14. Thrombocytopenia
15. Sideroblastic anaemia
Contra-indications of Pyrazinamide
1. Hypersensitivity to Pyrazinamide
2. Severe hepatic diseases
3. Acute gout

Special Precautions while taking Pyrazinamide
1. Diabetes mellitus
2. Renal impairment
3. Gout
Pregnancy Related Information
Use with caution
Old Age Related Information
Use with caution.
Breast Feeding Related Information
Use with caution
Children Related Information
May be used
NEONATES: Contraindicated
Indications for Pyrazinamide
Interactions for Pyrazinamide
Uricosurics: Antagonism of effect of probenecid and sulphinpyrazone.
INH: Significantly reduces INH serum concentrations.
Anti-diabetic agents: Affects control of diabetes in diabetics.

Typical Dosage for Pyrazinamide
Adult:15 - 30 mg / kg body weight/ day in single dose, maximum dose up to 3 g/ day or 50 - 70mg / kg body weight/ twice weekly
Children: Same as adult dose

Schedule of Pyrazinamide
Storage Requirements for Pyrazinamide
Store the drug at 15 - 30 degree C in a tightly closed container. Protect from heat and light. Keep out of the reach of children.
Effects of Missed Dosage of Pyrazinamide
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Pyrazinamide
Give supportive measures and symptomatic treatment. Drug can be removed from the body by gastric lavage or by inducing emesis. Absorption of the drug can be reduced by administration of activated charcoal.

Home Delivery for Pyrazinamide in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including pyrazinamide.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for pyrazinamide and other medicines and health products. Home delivery services for pyrazinamide may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take pyrazinamide only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for pyrazinamide before they complete the sale. You can get this information while placing the order for pyrazinamide with the pharmacy.

Pyrazinamide is a generic medicine name and there are several brands available for it. Some of the brands for pyrazinamide might be better known than pyrazinamide itself. If the pharmacy that's willing to deliver medicines to your home doesn't have pyrazinamide in stock, you can ask for one of the branded alternatives for pyrazinamide.