Dosage of antidepressant medication dispensed in Scotland.
OBJECTIVE
To examine the daily doses of the more frequently prescribed antidepressants in Scotland and to assess the extent of adequate dosage and its relationship to drug type.


METHODS
Monthly random sample of all prescriptions dispensed in Scotland over 1 year. Antidepressants were categorised into 5 groups, older tricyclics, newer tricyclics, atypical antidepressants, selective serotonin uptake inhibitors (SSRI's) and monoamine oxidase inhibitors (MAOI's). Percentage of prescriptions at or above the minimum effective dose was calculated for each group. In addition the total number and rank order of all antidepressant prescriptions in 1995 were calculated in order to examine sampling bias.


METHODS
Prescription data routinely collected by the Pharmacy Practices Division of the Common Services Agency of The NHS in Scotland.


RESULTS
Older tricyclics continue to be the most frequently prescribed antidepressants (51%), followed by SSRI's (34%), newer tricyclics and atypicals (7% each) and MAOIs (1%). Only 18% (95% C.I. 13-23%) of the sample of older tricyclics were prescribed at or above the minimum therapeutic level, compared to 99% (95% C.I. 95-100%) for SSRIS' 76% (95% C.I. 55-93%) for atypicals and 74% (95% C.I. 52-96%) for lofepramine.


CONCLUSIONS
Despite initiatives to improve the treatment of depressive illness in primary care, the majority of prescriptions continue to be for older tricyclic antidepressants at sub-therapeutic dosage. Incorporation of consensus statement guidelines about minimum effective doses for these drugs in the BNF may be an important and economical route to improving treatment of identified depressive illness.
Patience
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Shawpark Resource Center, 41, Shawpark Street, Glasgow G20 9DR.
D000928:Antidepressive Agents / Q000008:administration & dosage* / Q000145:classification; D003866:Depressive Disorder / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D011307:Drug Prescriptions; D017723:Drug Utilization Review; D006801:Humans; D017410:Practice Guidelines as Topic; D011320:Primary Health Care / Q000592:standards*; D011897:Random Allocation; D012606:Scotland; D013222:State Medicine
D000928:Antidepressive Agents