藥物警訊（藥師週刊第1766期）

Celexa (citalopram hydrobromide) - Drug Safety Communication: Revised Recommendations, Potential Risk of Abnormal Heart Rhythms

AUDIENCE: Psychiatry, Cardiology

FDA is clarifying dosing and warning recommendations for the antidepressant Celexa (citalopram hydrobromide; also available in generic form).In August 2011, FDA issued a Drug Safety Communication (DSC) stating that citalopram should no longer be used at doses greater than 40 mg per day because it could cause potentially dangerous abnormalities in the electrical activity of the heart. Citalopram use at any dose is discouraged in patients with certain conditions because of the risk of QT prolongation, but because it may be important for some of those patients to use citalopram, the drug label has been changed to describe the particular caution that needs to be taken when citalopram is used in such patients. The revised drug label also describes lower doses that should be used in patients over 60 years of age.

Read the FDA Drug Safety Communication for additional information.

BACKGROUND: Celexa (citalopram hydrobromide; also available in generic form) is in a class of antidepressants called selective serotonin reuptake inhibitors (SSRIs).

RECOMMENDATIONS:

* Citalopram is not recommended for use at doses greater than 40 mg per day because such doses cause too large an effect on the QT interval and confer no additional benefit.

* Citalopram is not recommended for use in patients with congenital long QT syndrome, bradycardia, hypokalemia, or hypomagnesemia, recent acute myocardial infarction, or uncompensated heart failure.?

* Citalopram use is also not recommended in patients who are taking other drugs that prolong the QT interval.

* The maximum recommended dose of citalopram is 20 mg per day for patients with hepatic impairment, patients who are older than 60 years of age, patients who are CYP 2C19 poor metabolizers, or patients who are taking concomitant cimetidine (Tagamet) or another CYP2C19 inhibitor, because these factors lead to increased blood levels of citalopram, increasing the risk of QT interval prolongation and Torsade de Pointes.

See the FDA Drug Safety Communication for additional recommendations for healthcare professionals and patients.

Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA's MedWatch Safety Information and Adverse Event Reporting Program:

* Complete and submit the report Online: www.fda.gov/MedWatch/report.htm

* Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to 1-800-FDA-0178

Read the MedWatch safety alert, including a link to the FDA Drug Safety Communication, at:
http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHuma...

FDA澄清抗憂鬱劑Celexa （citalopram hydrobromide）的劑量與警示建議。在2011年8月，FDA發布藥物安全警訊，聲明citalopram因有可能會引起心臟電位不正常，使用 劑量不應高於40 mg/day；且不鼓勵有QT interval prolongation風險的病人使用任何劑量的citalopram。但是對於某些此類病人而言，仍可能需用到citalopram。因此仿單更改為 當有風險的病人使用citalopram時，須特別注意。仿單也更新建議60歲以上病人需使用較低的劑量。

建議：

● 不建議citalopram使用劑量高於40 mg/day，因為可能會造成QT interval prolongation，而且沒有任何益處。

● 不建議citalopram使用於有先天性long QT症狀、心律過慢、低血鉀、低血鎂、最近有急性心肌梗塞或心衰竭的病人。

● 不建議citalopram使用於有服用會造成QT interval prolongation藥品的病人。

● 對於肝功能不佳、大於60歲、CYP2C19代謝差、併服cimetidine或其他CYP2C19抑制劑的病人，其血中citalopram濃度可能較 高，會增加QT interval prolongation及Tordade de Pointes的風險，故每日最高建議劑量為20 mg。

詳細資訊請見FDA網站上之Drug Safety Communication。

相關訊息與連結請參考FDA網址：

http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHuma...
[Posted 03/28/2012]

資料來源：美國FDA之藥物安全警訊
資料提供：台大醫院藥劑部