Daily citalopram dose shouldn't be higher than 40 mg

The antidepressant citalopram hydrobromide (Celexa) should no longer be used at doses greater than 40 mg/d, according to a new warning from the FDA.

Doses over 40 mg can cause prolongation of the QT interval and lead to an abnormal heart rhythm (including torsade de pointes), an FDA press release said. Trials of the drug have not shown a benefit in the treatment of depression at doses higher than 40 mg/d, but the citalopram drug label previously stated that certain patients may require a dose of 60 mg/d. The label has been revised to include the new dosage and usage recommendations.

An even lower dose, 20 mg/d, is the maximum recommended dose for patients who have hepatic impairment, are older than 60 years of age, are CYP 2C19 poor metabolizers, or are taking concomitant cimetidine (Tagamet), because these factors lead to increased blood levels of citalopram, increasing the risk of QT interval prolongation and torsade de pointes.

The FDA also advised clinicians that citalopram should not be used in patients with congenital long QT syndrome. In patients who do take the drug, hypokalemia and hypomagnesemia should be corrected before administering citalopram. Electrolytes should be monitored as clinically indicated. Physicians should consider more frequent electrocardiogram monitoring in patients who have congestive heart failure, those who have bradyarrhythmias, or those who take concomitant medications that prolong the QT interval.