Little information exists regarding the use of selective serotonin reu
ptake inhibitors (SSRIs) in the naturalistic setting. The Regenstrief
Medical Record System was used to analyze the dosing of SSRIs in the o
utpatient population of an urban teaching hospital. A cohort of 3350 p
atients was extracted, of whom 2859 had received fluoxetine and 460 se
rtraline. This cohort received 21,079 prescriptions. (The 31 patients
who were prescribed paroxetine were eliminated from further analysis.)
The mean daily dose for all patients receiving fluoxetine was 21 +/-
6 mg for the first prescription dispensed and 25 +/- 11 mg for the nin
th. For fluoxetine-treated patients with depression included on their
computerized medical problem list, the mean daily dose was 21 +/- 6 mg
for the first prescription and 26 +/- 12 mg for the ninth. A mean of
5.0% of all patients continuing fluoxetine therapy had their daily dos
e increased with each prescription refill during the first nine prescr
iptions. The mean daily dose for all patients receiving sertraline was
59 +/- 28 mg for the first prescription and 117 +/- 66 mg for the nin
th. For sertraline-treated patients with depression included on their
computerized medical problem list, the mean daily dose was 57 +/- 25 m
g for the first prescription and 110 +/- 65 mg for the ninth. A mean o
f 14.9% of all patients continuing sertraline therapy had their daily
dose increased with each prescription refill during the first nine pre
scriptions. The frequency of sertraline dose increases was 2 to 3 time
s the rate for fluoxetine. Because increases in daily doses typically
result from inadequate control of symptoms of depression, these findin
gs may reflect fluoxetine's greater effectiveness in controlling sympt
oms during the initial stages of therapy in the naturalistic setting.