Am. J. Respir. Crit. Care Med., Vol 152, No. 5, 11 1995, 1705-1708.
Aging and hepatotoxicity of isoniazid and rifampin in pulmonary tuberculosis
P van den Brande, W van Steenbergen, G Vervoort and M Demedts
Division of Pneumology, University Hospital, University of Leuven, Belgium.
We evaluated whether elderly patients with pulmonary tuberculosis and
without apparent preexisting liver disease are at an increased risk to
develop hepatotoxicity from an isoniazid-rifampin regimen and require
regular liver function tests in comparison with younger patients. We
analyzed the data of 131 patients treated in the period 1980-1985 of whom
64 (49%) were at least 60 yr of age. Subsequent increases of transaminases
(measured weekly for as long as 4 wk after the start of treatment and later
on when symptoms suggestive of hepatotoxicity occurred) above baseline
values were found more frequently in the elderly (38 versus 18%, p <
0.05) and were also more pronounced in them (p < 0.01). The ratio of the
highest transaminase value over the baseline value was called the
transaminase index (TI). A TI of at least 5 was found in 22% of elderly and
8% of younger patients (p = NS), but ratios as high as 10 were mostly
asymptomatic and always normalized progressively without treatment
adjustment. Only symptomatic patients with a TI > or = 10 (five elderly
and three younger) required temporary or definitive treatment adjustment.
We conclude that repeated liver function test evaluations are generally
unnecessary, except for symptomatic elderly and younger patients alike, in
order to detect those with a TI > or = 10, thus requiring drug
adjustment.
