Isoniazid Intravenous for Adults

Who can administer

May be administered by registered competent doctor or nurse/midwife

Important information

Unlicensed preparation

Available preparations

Isoniazid 300mg in 5ml ampoules (Cemidon)

Reconstitution

Not required - already in solution

Draw up using a 5 micron filter needle

Methods of intravenous administration

Bolus intravenous injection 

• Administer undiluted
• Give slowly over 3 to 5 minutes

Dose in adults

Tuberculosis, in combination with other drugs (standard unsupervised 6-month treatment)

• Give 300mg daily (initial and continuation phases)

Prevention of tuberculosis in susceptible close contacts or those who have become tuberculin positive

• Give 300mg daily

Monitoring

• Note: Cemidon contains sodium metabisulfite which may cause allergic reactions 
• Baseline liver enzymes not routinely recommended in latent TB except for patients with HIV, liver disease, immediate post-partum < 3 months, or regular alcohol use ^{(ref 3)}
• Baseline liver enzymes recommended in treatment of active TB; repeat liver function tests monthly if:
  • abnormalities at baseline
  • symptoms consistent with hepatotoxicity develop
  • patients chronically consume alcohol
  • patients take other potentially hepatotoxic medications
  • patients have viral hepatitis or history of liver disease, human immunodeficiency virus (HIV) infection, or prior drug-induced liver injury ^{(ref 3)}
• If no evidence of liver disease (and pre-treatment liver function is normal), further checks are only necessary if the patient develops fever, malaise, vomiting, jaundice or unexplained deterioration during treatment.
• Monitor: for skin reactions, temperature, liver function (weekly for the first month, then monthly) ^{(ref 1)}
• Caution: numerous drug interactions ^{(ref 3)}

Further information

• Give oral pyridoxine to reduce the risk of peripheral neuropathy occurring ^{(ref 2)}
• At low temperatures, isoniazid in solution may crystallise; warm the injection to room temperature to re-dissolve the crystals before use ^{(ref 2)}
• Injection solution is given undiluted.  However, it is known to be compatible with Sodium chloride 0.9%

Storage

Store below 25⁰C

References

1. BNF - medicinescomplete.com. Accessed Oct 30th 2024
2. Medusa NHS Injectable Medicines Guide. Accessed Oct 30th 2024
3. Sanford Guide. Accessed Oct 30th 2024

Therapeutic classification

Antimycobacterial