Rifafour is a fixed-dose combination of the following four active TB drugs: 

Rifampicin 150 mg

lsoniazid 75 mg

Pyrazinamide 400 mg

Ethambutol HCI 275 mg

This regimen is considered the standard approved treatment for drug-sensitive Tuberculosis. 

Pyridoxine is the 4-methanol form of vitamin B6, an important water-soluble vitamin that is naturally present in many foods. As its classification as a vitamin implies, Vitamin B6 (and pyridoxine) are essential nutrients required for normal functioning of many biological systems within the body.