If this medicine upsets your stomach, take it with food. Antacids may also help. However, do not take aluminum-containing antacids within 1 hour of the time you take rifampin and isoniazid combination. They may keep this medicine from working properly.
To help clear up your tuberculosis (TB) completely, it is very important that you keep taking this medicine for the full time of treatment, even if you begin to feel better after a few weeks. You may have to take it every day for as long as 1 to 2 years or more. It is important that you do not miss any doses.
Your doctor may also want you to take pyridoxine (e.g., Hexa-Betalin, vitamin B 6) every day to help prevent or lessen some of the side effects of isoniazid. If it is needed, it is very important to take pyridoxine every day along with this medicine. Do not miss any doses.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
For the oral dosage form (capsules):
For the treatment of tuberculosis:
Adults and older children—600 milligrams (mg) of rifampin and 300 mg of isoniazid once a day.
Children—This combination medicine is not recommended for use in children.
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.