Special situations

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).