[Citalopram and desmethylcitalopram for psychiatric patients].
Serum samples were selected randomly from blood samples drawn in the morning for other reasons in patients treated with citalopram, and the serum concentrations of citalopram (S-citalopram) and its major metabolite desmethylcitalopram were determined. A total of 44 patients, 13 males and 31 females, with a median age of 38.5 years (range 18-89) entered the study. In 17 patients given 20 mg/day of citalopram the S-citalopram was (median and range) 153 nmol/l (83-237). In 24 patients treated with citalopram 40 mg/day the S-citalopram was 240 nmol/l (range 0-360). In one serum sample no S-citalopram could be detected (non-compliance) and in another sample S-citalopram was just above the detection limit (about 3 nmol/l). The latter may at least partly be due to treatment with 600 mg/day of carbamazepine, which is known to accelerate the metabolism of other drugs. The serum concentration of the major metabolite desmethylcitalopram averaged 28% of S-citalopram and is most likely without clinical importance. It is concluded that determination of S-citalopram may be considered if there is doubt about the compliance of the patient, in drug interaction cases or if the clinical effect is poor. If high S-citalopram
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Afdeling for biologisk psykiatri, Psykiatrisk Hospital i Arhus.
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D000293:Adolescent; D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D015283:Citalopram / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D003866:Depressive Disorder / Q000188:drug therapy*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance
D000928:Antidepressive Agents; D015283:Citalopram