Short-term dose response characteristics of acetazolamide in man
B. R. Friedland, J. Mallonee and D. R. Anderson
Nine patients with ocular hypertension each randomly received on separate
days 0, 63, 125, 250, and 500 mg of acetazolamide (Diamox). In a double
masked manner, acetazolamide plasma levels and intraocular pressure were
monitored for seven hours following administration. Plasma levels increased
linearly with dose, reaching 30 microgram/ml with the 500-mg dose. Maximum
plasma levels occurred at one hour, and the minimum IOP was at two hours.
The maximum IOP effect was a 30% to 35% fall. The IOP response was related
to dose and plasma level, up to a 63-mg dose, which produced an average
fall of 8.2 mm Hg. Little further average effect was documented at higher
doses or plasma levels. The duration of response was slightly prolonged by
250 mg, but 500 mg showed no greater response. Thus, a 63-mg dose or a
plasma level of 4 to 5 microgram/ml was as effective in lowering IOP as
higher doses that produced plasma levels of 10 microgram/ml or more.
