張國華 醫師 於 2007-03-07 10:59:34 回覆

所問問題，目前尚未有文獻確定註明，注射肉毒桿菌素後多久，可以懷孕而無安全上的顧慮。

根據全世界最大肉毒桿菌素藥廠Allergan有關懷孕婦女患者的說明原文如下：
There are no adequate and well-controlled studies of BOTOX® Cosmetic in pregnant women. When pregnant mice and rats were injected intramuscularly during the period of organogenesis, the developmental NOEL (No Observed Effect Level) of BOTOX® Cosmetic was 4 U/kg. Higher doses (8 or 16 U/kg) were associated with reductions in fetal body weights and/or delayed ossification.

中文解說：

1.為懷孕老鼠注射肉毒桿菌素4U/Kg,相當於50公斤患者一次注射整整兩瓶肉毒桿菌素，實驗觀察中，無異常發現。

2.老鼠注射肉毒桿菌素8~16U/Kg,相當於50公斤患者，一次注射4~8瓶肉毒桿菌素後，發現老鼠胎兒體重減小，鈣化延遲。


肉毒桿菌素的藥物動力學原文如下：

Pharmacokinetics
Pharmacokinetic studies in humans are not practicable with BOTOX®.
Distribution studies in rats indicate slow muscular diffusion of botulinum neurotoxin A complex in the gastrocnemius muscle after injection, followed by rapid systemic metabolism and urinary excretion. The amount of radiolabelled material in the muscle declined at a half-life of approximately 10 hours. At the injection site the radioactivity was bound to large protein molecules, whereas in plasma it was mostly bound to small molecules, suggesting rapid systemic metabolism of the substrate. Within 24 hours of dosing, 60% of the radioactivity was excreted in the urine. Autoradiographic results after intramuscular injection of 125I-botulinum neurotoxin A complex into the proximal inner surface of the upper eyelids of rabbits also indicate slow muscular diffusion.

中文解說：

在老鼠小腿肌肉內，注射肉放射性同位素標定的毒桿菌素，發現肉毒桿菌素約於10小時以後，僅有一半存在肌肉中。24小時以內，60％的肉毒桿菌素，已經隨尿液排出體外。

＊筆者補充說明＊

1.由於老鼠與人類的物種差異，上述內容僅供參考。

2.以老鼠產生胎兒影響的劑量8U/Kg來說，相當於50公斤體重患者，一次注射四瓶肉毒桿菌素--以皺眉紋與魚尾紋來說，通常注射量不會超過一瓶劑量。

3.依據肉毒桿菌素代謝時間估算，注射後一週內，已經排出體外達99.9%以上。換句話說，如果在注射肉毒桿菌素超過一週以後懷孕的話，肉毒桿菌素的影響，理論上來說，將是微乎其微。

但是為了安全考量，以及懷孕日期誤差機率的可能性，筆者建議，如果注射肉毒桿菌素，原則上最好在超過一個月之後再懷孕，比較安心。