It is very important that your doctor check your progress at regular visits. Blood tests may be needed to check for unwanted effects.
If your symptoms do not improve within 2 to 3 weeks, or if they become worse, check with your doctor.
You should not use this medicine if you are also receiving certain medicines to treat HIV infection (such as atazanavir, darunavir, fosamprenavir, ritonavir, saquinavir, tipranavir, Aptivus®, Fortovase®, Invirase®, Lexiva®, Norvir®, Prezista®, or Reyataz®).
Liver problems may be more likely to occur if you drink alcoholic beverages regularly while you are taking this medicine. Also, the regular use of alcohol may keep this medicine from working properly. Therefore, you should strictly limit the amount of alcoholic beverages you drink while you are taking this medicine.
Check with your doctor immediately if blurred vision, difficulty in reading, or any other change in vision occurs during or after treatment. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).
Stop using this medicine and check with your doctor right away if you have joint pain, stiffness, or swelling; lower back, side, or stomach pain; or swelling of the feet or lower legs.
This medicine will cause urine, stool, saliva, sputum, sweat, and tears to turn reddish-orange to reddish-brown. This is to be expected while you are taking this medicine. This effect may cause soft contact lenses to become permanently discolored. Standard cleaning solutions may not take out all the discoloration. Therefore, it is best not to wear soft contact lenses while taking this medicine. Hard contact lenses are not discolored by this medicine. This condition will return to normal once you stop taking this medicine. If you have any questions about this, check with your doctor.
If this medicine causes you to feel very tired or very weak; or causes clumsiness; unsteadiness; a loss of appetite; nausea; numbness, tingling, burning, or pain in the hands and feet; or vomiting, stop taking it and check with your doctor immediately. These may be early warning symptoms of more serious liver or nerve problems that could develop later.
Rifampin, isoniazid, and pyrazinamide combination may cause blood problems. These problems may result in a greater chance of certain infections, slow healing, and bleeding of the gums. Therefore, you should be careful when using regular toothbrushes, dental floss, and toothpicks. Dental work should be delayed until your blood counts have returned to normal. Check with your medical doctor or dentist if you have any questions about proper oral hygiene (mouth care) during treatment.
If you develop a skin rash, hives, or any allergic reaction to this medicine, stop taking the medicine and check with your doctor as soon as possible.
Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.
Eating certain foods (such as cheese [Swiss or Cheshire] or fish [e.g., skipjack, tuna, or Sardinella]) or drinking red wine may cause reactions in some patients taking isoniazid-containing medicines. Check with your doctor if flushing, fast or pounding heartbeat, headache, redness or itching of the skin, sweating, dizziness, or lightheadedness occurs while you are taking this medicine.
Birth control pills may not work properly while you are taking this medicine. To keep from getting pregnant, use another form of birth control along with your birth control pills. Other forms include condoms, diaphragms, or contraceptive foams or jellies.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.