Monitoring liver function with glitazone therapy

This is recommended as (1):

• checking liver enzymes prior to the initiation of therapy and then monitoring them every 2 months for the first 12 months of glitazone therapy, and periodically thereafter
• if ALT levels are increased to 3x upper limit of normal then there should be a reassessment of the liver enzymes as soon as possible. Glitazone therapy should be discontinued if levels remain > 3x the upper limit of normal

A Drugs and Therapeutics Bulletin review (2) states that 'the drugs are also contraindicated in patients with impaired liver function (i.e. with ALT levels more than 2.5 times the upper limit of normal) or any other signs of liver disease.' The British National Formulary however states that a contraindication to glitazone therapy is hepatic impairment and does not qualify this with respect to liver function tests.

Reference:

1. CSM/MCA (2001). Current problems in pharmacovigilance, 27, 11.
2. Drugs and Therapeutics Bulletin (2001), 39 (9), 65-68.