Safety Notices
September 25, 2009
ST LOUIS (MD Consult) - On September 23, 2009, Roche issued an alert to health care professionals and pharmacists clarifying the dosing instructions for the oral suspension formulation of influenza drug Tamiflu (oseltamivir). In conjunction with this notice, the US Food and Drug Administration (FDA) issued a public health alert after it received reports of dosing errors that occurred as a result of mismatches between prescribed patient dosing instructions and the markings on dosing dispensers provided with the product.
Practitioners in the United States usually write prescriptions for liquid medicines in milliliters (mL) or teaspoons (tsp). Tamiflu is dosed in milligrams (mg), and the dosing dispenser packaged with Tamiflu has markings only in 30, 45, and 60 mg. Incidents have occurred where the units of measure specified in the instructions on the prescription label (mL, tsp) did not match the units on the dosing device (mg), which has in turn led to patient or caregiver confusion and dosing errors.
Pharmacists are being instructed to ensure that the units of measure on the prescription instructions match the dosing device when dispensing commercially manufactured Tamiflu for oral suspension (12 mg/mL). If prescription instructions specify administration using milligrams, as per the approved dosing recommendations, then the device included in the Tamiflu product package should be provided to patients, and the prescription label should provide dosing instructions in milligrams. Conversely, if prescription instructions specify administration using millilters or teaspoons, then the device included in the Tamiflu product package should be removed and replaced with an appropriate measuring device, such as an oral syringe if the prescribed dose is in milliliters.
Prescribers are being asked to avoid prescribing doses of Tamiflu oral suspension in teaspoons because this action can lead to inaccurate dosing. If dosing instructions are specified in teaspoons, the pharmacist should convert the volume to milliliters and ensure that an appropriate measuring device is provided.
The FDA notice includes the following table showing the dosing instructions for Tamiflu in both milligrams and milliliters for the treatment of influenza:
Dose of Tamiflu oral suspension (12 mg/mL) for the treatment of influenza
|
Body Weight (kg)
|
Body Weight (lbs)
|
Recommended Dose
for 5 Days
(If using the dosing device supplied with the product)
|
Dose (mL)
(If using a syringe marked in mL or cc)
|
Number of Bottles of Tamiflu Needed to Obtain the Recommended Doses for a 5-Day Regimen
|
|
<15 kg
|
<33 lbs
|
30 mg twice daily
|
2.5 mL
|
1
|
|
>15 kg to 23 kg
|
>33 lbs to 51 lbs
|
45 mg twice daily
|
3.8 mL
|
2
|
|
>23 kg to 40 kg
|
>51 lbs to 88 lbs
|
60 mg twice daily
|
5.0 mL
|
2
|
|
>40 kg
|
>88 lbs
|
75 mg twice daily
|
6.2 mL
|
3
|
安全须知
2009年9月25日
圣路易斯(MD Consult)——2009年9月23日，罗氏公司向医务工作者和药剂师发出一份警告，以澄清流感防治药物达菲(奥司他韦)口服混悬液制剂的用药指导。与此同时，美国食品药品管理局(FDA)在接获数起因处方中的用药指导与产品配备的分药刻度计不相符而导致用药剂量错误的报告后，向公众发出一份健康警告。
在美国，医生在开具液体药物处方时通常使用毫升(ml)或茶匙(tsp)作为计量单位。达菲采用毫克(mg)计量，且达菲口服混悬剂只配备30 mg、45 mg和60 mg分药刻度计。目前，已发生多起处方签用药指导的计量单位(ml, tsp)与刻度装置(mg)不符的事件，这反过来又导致患者或医护人员产生混淆并导致用药剂量错误。
药剂师须确保处方用药指导的计量单位与商业化产品达菲口服混悬液(12 mg/ml)分药所使用的刻度装置相符。如果处方用药指导按照获批的推荐计量方式使用毫克单位给药，则应向患者提供达菲产品包装配备的量药器，且处方签中的用药指导也应使用毫克单位。反之，如果处方用药指导使用毫升或茶匙单位给药，则无需使用达菲产品包装中的量药器，而以合适的量药器代替，譬如说，如果处方剂量单位为毫升则采用口服注射器给药。
通知要求医生在开具达菲口服混悬液处方时应避免使用茶匙单位，因为这样可能会导致定量不准确。如果在用药指导中使用茶匙单位，药剂师则应将其转换为毫升数，并确保使用合适的量药器。
该FDA须知使用下列表格表示达菲治疗流感用药指导中毫克与毫升的对应关系：
达菲口服混悬液治疗流感的剂量(12 mg/ml)
|
体重 (千克, kg)
|
体重 (磅, lbs)
|
5日方案推荐剂量(如果使用药物配备的刻度装置)
|
剂量(ml)(如果使用以ml或cc为单位的注射器)
|
5日方案推荐剂量所需的达菲瓶数
|
|
<15 kg
|
<33 lbs
|
30 mg, 每天2次
|
2.5 ml
|
1
|
|
>15 kg, <23 kg
|
>33 lbs, <51 lbs
|
45 mg, 每天2次
|
3.8 ml
|
2
|
|
>23 kg, <40 kg
|
>51 lbs, <88 lbs
|
60 mg, 每天2次
|
5.0 ml
|
2
|
|
>40 kg
|
>88 lbs
|
75 mg, 每天2次
|
6.2 ml
|
3
|
