Tuberculosis (TB) is an airborne infectious disease that involves mycobacterium tuberculosis bacteria. It can be either asymptomatic or symptomatic. Lung is the most common site for tuberculosis, but it can also affect other body parts. TB can be latent or active, and about one-tenth of latent tuberculosis patients may become active and infectious. Isoniazid inhibits the production of cell walls of mycobacterium tuberculosis, thus killing it and treating tuberculosis. It can be used together with another antibiotic, Rifampicin, to treat tuberculosis in adults and children. In Hong Kong, although newborn infants would get the Bacillus Calmette–Guérin (BCG) vaccine for free, there might still be a chance to get infected.
Isoniazid is available in tablets for oral administration. It is usually administered for 2 months with Rifampicin + Pyrazinamide + Ethambutol, followed by an additional 4-7 months with Rifampicin.
For tuberculosis, in combination with other antitubercular drugs:
5 mg/kg daily, up to 300 mg/day.
Twice- or Three-times-weekly dosing:
15 mg/kg twice or three times weekly, up to 900 mg/day.
Common dosing schedule:
Isoniazid should be administered on an empty stomach.
This schedule is for reference only, adjustments may be made according to individual needs.
Some common medications Isoniazid may interact with:
Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.
In Hong Kong, Isoniazid is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.
For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk
Need more information?
For detailed information about the use of Isoniazid in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.
Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.