Phentermine and anaesthesia.

Department of Anaesthesia, The Royal Hospital for Women, Sydney, New South Wales.

Anaesthesia and intensive care 2005 Aug

We describe the case of a woman who had two penroperative hypertensive crises that may have been due to her use of phentermine, a little-known sympathomimetic anti-obesity medication. The currently available anti-obesity medications are discussed: phentermine, diethylpropion, and sibutramine; all of which are sympathomimetics possessing noradrenaline and serotonin reuptake inhibitor activity. These medications should be discontinued one week preoperatively and have potential interactions with tramadol and antidepressants. The drug orlistat inhibits gastrointestinal lipase and may lead to fat soluble vitamin (A, D, E, and K) deficiency, so consideration should be given to checking coagulation status preoperatively.