How long does phentermine stay in the body. I am planning to stop taking it 4 weeks before my surgery. Is that good?

Doctor Answers 1

Phentermine and cosmetic surgery

Phentermine is an amphetamine (speed) like medication used as an appetite suppressant to treat obesity. It is only recommended for short term use because it can cause psychological dependency and has a high potential for abuse. Abruptly stopping it after prolonged use can cause fatigue and depression. It used to be prescribed as part of the Phen-Fen treatment for obesity until it was noted that the combination of medications caused high pressure in the blood vessels of the lungs, loss of exercise endurance and secondary heart problems. Combined with general anesthesia it can cause abnormal and dangerous heart rhythms.

The half life of the medication (amount of time it takes the body to cut the blood levels in half after you stop the medication) can be as high as 25 hours. Since it takes 4 to 5 half lives to clear a medication or reach a new higher blood level it could take as long as 100 to 125 hours (4 or 5 days) to clear the medication from your system after you stop taking it. Therefore you need to stop it at least 5 days before surgery. If you have been taking it for a long time you will need to slowly cut the doseage before you stop it completely.

My response to your question/post does not represent formal medical advice or constitute a doctor patient relationship. You need to consult with i.e. personally see a board certified plastic surgeon in order to receive a formal evaluation and develop a doctor patient relationship.

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