Both prescription and non-prescription medicines, herbal preparations and dietary supplements may interact adversely with Phentermine. In particular, you should seek detailed advice if you are taking:
• a monoamine oxidase inhibitor (MAOI) — a class of powerful antidepressant drugs including Redux (dexfenfluramine), Pondimin (fenfluramine) or Nardil (phenelzine).
You must wait at least fourteen days before taking Phentermine to allow the MAOI to clear your body. There are serious risks of side effects including an increasingly severe headaches, high blood pressure, slow heart rate, elevated temperature or, in very rare cases, fatal lung problems;
• Serotonin specific reuptake inhibitors (SSRIs) — a class of antidepressants including Zoloft (sertraline) and Prozac (fluoxetine) because Phentermine increases the risks of their side effects;
• Hylorel (guanadrel) or Ismelin (guanethidine), antihypertensive drugs that reduce the release of catecholamines such as noradrenaline, because Phentermine may reduce their effectiveness.
This list is not exhaustive. You should check with your physician before adding Phentermine to any other medications or health products you are taking.
Articles