ARZADE 450MG/300MG CAPSULE is a combination of two antibiotics: Rifampicin and isoniazid which treat tuberculosis. Rifampicin works by inactivating a bacterial enzyme (RNA-polymerase) which is required by TB bacteria to make essential proteins and to reproduce. Isoniazid prevents the TB-causing bacteria from forming their own protective covering. Together, they kill the bacteria and eradicate the infection.