Adult

Isoniazid

General Information

Tablets and Liquid are Restricted formulary antimicrobials: For details see OUH netFormulary

Injection is Unlicensed Restricted formulary antimicrobial: For details see OUH netFormulary 

For all information regarding contra-indications, interactions, contraception, pregnancy and breastfeeding and additional information, see BNF and Summary of Product Characteristics (SPC).

Standard dose

See Isoniazid - TB DRUG MONOGRAPHS

Renal and hepatic impairment

Renal impairment

eGFR (mL/min/1.73m2) Dose
More than 10 Dose as in normal renal function
Less than 10 200-300mg OD
HD/HDF/High Flux/PD

Dialysed; give after dialysis

Dose as in eGFR less than 10ml/min/1.73m2

 

Note: Doses are based on Renal Drug Database

  • Risk of ototoxicity and peripheral neuropathy enhanced in renal impairment. Ensure pyridoxine is prescribed.

 

Hepatic impairment

  • Use with caution in hepatic impairment. 
  • In patients with pre-existing liver disease or hepatic impairment monitor liver function regularly and particularly frequently in the first 2 months.

Therapeutic Drug Monitoring

See Isoniazid - TB DRUG MONOGRAPHS

References

  1. Morningside Healthcare Ltd. Isoniazid 100mg tablets summary of product characteristics.  Electronic medicines compendium. Last revision of the text 12/2/19. Accessed via www.medicines.org.uk Accessed 30/9/26.
  2. British National Formulary. Isoniazid. BNF online accessed via www.medicinescomplete.com  Accessed 30/9/26.
  3. The Renal Drug Database. Isoniazid. Last updated 8/11/24 Accessed via https://renaldrugdatabase.com Accessed 30/9/26.
  4. Sanford guide [online]. Isoniazid. Last updated 9/7/26. Accessed via https://webedition.sanfordguide.com Accessed 30/9/26.

Editorial Information

Last reviewed: 30 Sept 2026

Next review date: 27 Sept 2029

Author(s): AMST.