Uses of Refzo- 4 FDC: - Tuberculosis (TB) Tuberculosis Hypersensitivity, history of drug-induced hepatitis, acute liver disease, peripheral or optic neuritis, renal dysfunction, epilepsy, chronic alcoholism.

How to use Ethambutol + Isoniazid + Pyrazinamide + Rifampicin: Take this medicine in the dose and duration as advised by your doctor. Check the label before use. Ethambutol + Isoniazid + Pyrazinamide + Rifampicin is to be taken empty stomach. Avoid Ethambutol + Isoniazid + Pyrazinamide + Rifampicin with tyramine-rich food such as cheese, smoked fish, meats and some types of beer. Administration: Should be taken on an empty stomach: Take at least1 hour before or 2 hours after a meal with a full glass of water. Swallow whole. Adult Dose: Fixed-dose combinations (FDCs) Tablets Rifampicin 150mg + Isoniazid 75mg + Pyrazinamide 400mg + Ethambutol 275mg (4FDC) New patients: Body weight 30-37kg: Initial 2 months- 4-FDC 2 tablets at a time daily; next 4 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 2 tablets at a time daily. 38-54kg: Initial 2 months- 4-FDC 3 tablets at a time daily; next 4 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 3 tablets at a time daily. 55-70kg: Initial 2 months- 4-FDC 4 tablets at a time daily; next 4 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 4 tablets at a time daily. >70kg: Initial 2 months- 4-FDC 5 tablets at a time daily; next 4 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 5 tablets at a time daily. Re-treatment patients: Body weight 30-37kg: Initial 3 months- 4-FDC 2 tablets at a time daily; & Streptomycin 500mg daily, next 5 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 2 tablets at a time daily, & Ethambutol 400mg 2 tablets at a time daily. 38-54kg: Initial 3 months- 4-FDC 3 tablets at a time daily; & Streptomycin 750mg daily, next 5 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 3 tablets at a time daily, & Ethambutol 400mg 3 tablets at a time daily. 55-70kg: Initial 3 months- 4-FDC 4 tablets at a time daily; & Streptomycin 1g daily, next 5 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 4 tablets at a time daily, & Ethambutol 400mg 3 tablets at a time daily. >70kg: Initial 3 months- 4-FDC 5 tablets at a time daily; & Streptomycin 1g daily, next 5 months- continuation dose 2-FDC (Rifampicin 600mg + Isoniazid 300mg) 5 tablets at a time daily, & Ethambutol 400mg 4 tablets at a time daily. The dose of streptomycin should not exceed 750mg daily after the age of 50 years.

Rifampicin: Induces microsomal enzymes (accelerates clearance of methadone, oral anticoagulants, glucocorticoids, oestrogen, oral hypoglycaemic agents, digitoxin, antiarrhythmics, theophylline, anticonvulsants, ?-blockers, azole antifungal, cyclosporin). INH: Inhibits metabolism of antiepileptics, benzodiazepines, warfarin, theophylline. Increases metabolism of enflurane. Alcohol, ASA, Al-containing antacids, corticosteroids, ketoconazole, propranolol. PZA: Decreases efficacy of gout therapy agents. Ethambutol: Neurotoxic agents.

Hypersensitivity, history of drug-induced hepatitis, acute liver disease, peripheral or optic neuritis, renal dysfunction, epilepsy, chronic alcoholism.

Common - Nausea - Vomiting - Rash - Fever - Dark colored urine - Sweating - Increased sputum production - Salivation - Watery eyes - Peripheral neuropathy (tingling and numbness of feet and hand) - Increased liver enzymes - Jaundice - Increased uric acid level in blood - Visual impairment Rifampicin: Reddish discolouration of body fluids, asymptomatic increase in liver enzymes, elevations of BUN & uric acid, hemolysis, hematuria, intestinal nephritis, renal insufficiency, GI discomfort, CNS effects, hematological changes, skin rash, endocrine effects. INH: Disturbances of liver function, hepatitis, GI disturbances, peripheral neuropathy, dizziness, lightheadedness, hematological changes, allergic reactions. Pyrazinamide: Transient rise in serum transaminases, hepatotoxicity, hepatomegaly, jaundice, hyperuricemia, intestinal nephritis, dysuria, GI disturbances, hematological changes, allergic reactions. Ethambutol: Confusion, disorientation, headache, visual disturbances, jaundice, transient liver dysfunction, GI disturbances, hematological changes, allergic effects, acute gout (rare).

Precaution: Impaired renal or liver function, DM, chronic alcoholism, undernourishment, history of gout, patients w/ convulsive disorders, acute porphyria. Elderly. Pregnancy & lactation. Perform periodic blood counts & liver function tests. Avoid use w/ soft contact lenses. Childn <8 yr or patients who are not able to communicate visual disturbances. Check visual ability before starting treatment & monitor during treatment.

Rifampicin, isoniazid and pyrazinamide are all active bactericidal antituberculosis drugs. Rifampicin and isoniazid are particularly active against the rapidly growing extracellular organisms and have an intracellular bactericidal activity. Rifampicin also inhibits DNA-dependent RNA polymerase activity in susceptible cells and it has activity against slow and intermittently-growing M tuberculosis. Pyrazinamide, particularly in the acid pH environment of macrophages is active against intracellular organisms. Combination of these agents covers activity against the 3 different bacterial populations. Ethambutol interferes with RNA synthesis, causing suppression of Mycobacteria multiplication. It also has bacteriostatic action against M tuberculosis by acting on rapidly growing pathogens in cavity walls and is also effective in slow-growing pathogens. Has some action against atypical opportunistic Mycobacteria e.g. M kansasii, M avium complex (MAC).