Indications
Thiacetazone is an older anti tuberculosis medicine. It is used only in combination with Isoniazid, usually as a fixed combination tablet, as part of a tuberculosis (TB) treatment plan. It has largely been replaced by more effective and safer regimens containing Rifampicin, and is now used rarely and only under a doctor or TB programme.
How It Works
Thiacetazone slows the growth of Mycobacterium tuberculosis, the germ that causes TB, by interfering with the building of its waxy cell wall. Combined with Isoniazid, it helps prevent the germs from becoming resistant to Isoniazid.
Dosage and Administration
Take exactly as prescribed by your doctor or TB programme, usually once daily. TB treatment must be taken every day for the full course, often many months, even when you feel well. Missing doses can lead to drug resistant TB.
Interactions
- Streptomycin may increase the risk of ear and balance problems.
- Isoniazid in the combination can raise levels of Phenytoin and Carbamazepine.
- Alcohol increases the risk of liver damage.
- Antacids may reduce absorption of Isoniazid; take them at a different time.
Contraindications
- Allergy to Thiacetazone or Isoniazid.
- People with HIV infection: Thiacetazone can cause severe and sometimes fatal skin reactions in people with HIV and must not be used.
- Liver disease.
- A past serious skin reaction to any medicine.
Side Effects
Possible effects include nausea, vomiting, loss of appetite, skin rash, itching, dizziness, ringing in the ears, and, from Isoniazid, tingling or numbness of the hands and feet and liver problems. Rarely it can lower blood counts.
Stop taking it and get urgent medical help if you develop any skin rash, especially with blisters, peeling, mouth sores or fever (signs of a serious reaction such as Stevens Johnson syndrome), or yellow skin or eyes, dark urine, severe tiredness, unusual bleeding or bruising.
Pregnancy and Lactation
Safer TB medicines are usually preferred in pregnancy and breastfeeding. Do not stop TB treatment on your own; your doctor will choose the best regimen.
Precautions and Warnings
- An HIV test is advised before use.
- Pyridoxine (vitamin B6) is often given to prevent nerve damage from Isoniazid.
- Liver function may be checked during treatment.
- Avoid alcohol.
Overdose
Overdose, especially of Isoniazid, can cause vomiting, dizziness, slurred speech, fits and coma. Seek emergency medical help immediately.
Therapeutic Class
Anti tuberculosis agent (thiosemicarbazone), used with Isoniazid.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.