Escitalopram dosage

Reduce the initial dosage of paroxetine in patients with severe renal impairment. Use sertraline and escitalopram with caution in patients with severe renal impairment. 

A 22-year-old man who had had ADHD since the age of 8 years took methylphenidate, and had an adequate response for 14 years (52). However, his symptoms worsened and he switched from methylphenidate to mixed amfetamine salts 20 mg bd. A month later he continued to have difficulty in focusing on tasks, and the dosage was eventually increased to 45 mg tds over several weeks, with symptomatic improvement. However, 5 days later, he awoke feeling nauseated and agitated and had choreiform movements of his face, trunk, and limbs. He had also taken escitalopram 10 mg/day for anxiety and depression for 2 months before any changes in his ADHD medications. He was treated with intravenous diphenhydramine, lora-zepam, and diazepam without improvement in the chorea. Amfetamine was withdrawn and 3 days later his chorea abated. He restarted methylphenidate and the movement disorders did not recur. 

The starting dose for fluvoxamine is 50 mg/day, which is then increased as tolerated and needed up to 300 mg/day divided into twice-daily doses. If citalopram is used, the initial dose is 20 mg/day, and it may be increased to 40 mg/day after 2 weeks. The starting dose for escitalopram is 10 mg/day, and it can be increased to a maximum of 20 mg/day. The dosage should be tapered slowly (i.e., decreasing sertraline by 50 mg/month or paroxetine by 10 mg/month) to decrease... 

No dosage adjustment is required in patients with mild to moderate renal impairment however, escitalopram should be used with caution in patients with severe renal impairment. Escitalopram is contraindicated in combination with irreversible monoamine oxidase inhibitors (MAOis), and a period of at least 2 weeks should be allowed between discontinuation of escitaiopram and commencement of an irreversible MAOi and vice versa. Escitaiopram appears to be a well-tolerated and effective antidepressant. 

The manufacturers suggest that potent inhibitors of CYP2D6, such as fluoxetine and paroxetine would be expected to increase aripiprazole levels, and they recommend that the dose of aripiprazole should be halved if these drugs are given. The UK manufacturer suggests that weaker inhibitors of this isoenzyme (they name escitalopram) would only be expected to cause modest increases in aripiprazole levels, and therefore no dosage adjustment would expected to be required. ... 

The authors of the citalopram study say that while cimetidine certainly causes an increase in the serum levels of citalopram, the extent is only moderate and because the drug is well tolerated and there are very considerable pharmacokinetic variations between individual subjects, they consider that there is no need to reduce the citalopram dosage. This advice is most likely applicahle to escitalopram, the S-isomer of citalopram. However, the manufacturer of escitalopram suggests caution, and advises that a reduction in the dose of escitalopram may he necessary (based on monitoring of adverse effects) during concurrent treatment. ... 

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