Key takeaways
Isoniazid (generic) and Rifampin (Rifadin) are both antibiotics used to treat tuberculosis (TB), but they have some key differences. Isoniazid is a first-choice medication for both treating and preventing TB and works by stopping the bacteria from making their protective covering. It can be taken alone for TB prevention but must be combined with other antibiotics for active TB treatment. Rifampin, on the other hand, is also used to treat TB and can prevent the spread of meningococcal infections in carriers. It works by blocking an enzyme the bacteria need to grow. Rifampin can be taken alone for treatment of latent TB but must be combined with other antibiotics for active TB treatment. Rifampin is typically taken once daily and can change the color of your body fluids, like urine and sweat, to a red-orange hue. Both medications can cause liver injury, so you should avoid alcohol while taking them. Isoniazid may require you to take vitamin B6 supplements to prevent nerve problems, while Rifampin can interact with many medications and lower their effectiveness. Both medications are available in both oral and injectable forms.
