special situations

Last reviewed 01/2018

Consult specialist advice.

The common special situations are:

• renal failure:
• rifampicin, isoniazid and pyrazinamide may be used in standard doses
• streptomycin and ethambutol should be used with caution and require close monitoring of drug levels

• pregnancy (1):
• streptomycin (hearing loss of the child due to permanent damage of the eighth nerve); also ethionamid should be avoided
• drugs that can be used in pregnancy, generally in combination, are ethambutol, isoniazid and rifampicin
• ethambutol is the first-line treatment
  • easy for the patient to take and reasonably safe in pregnancy
• if woman is receiving isoniazid the she should also take pyridoxine (50mg per day) - this is because isoniazid is known to cause peripheral neuritis and there is an increased requirement for this vitamin in pregnancy
  • isoniazid treatment may cause hepatitis - thus patients should have monthly liver function tests
• breast feeding is relatively safe with both ethambutol, isoniazid and and rifampicin
• rifampicin and isoniazid may be used in standard doses
• pyrazinamide, can be used in pregnancy beyond the first trimester provided that the benefits outweigh potential risks
• tuberculosis therapy should continue for six to nine months depending on the chemotherapeutic regimen followed
• the neonate should receive prophylactic isoniazid for three months and, in the UK, a BCG vaccination is given after this period

• liver disease:
• rifampicim, isoniazid, pyrazinamide and ethambutol may be use in standard doses
• liver function tests should be performed regularly

• tuberculous meningitis:
• rifampicin, isoniazid, pyrazinamide and ethionamide enter the CSF most effectively
• intrathecal administration is not required

Reference:

1. Prescriber (2005); 16 (8).