More threads by TheLight

David Baxter PhD

Late Founder
Following Steve's advice above, I found this:

Drug interaction results for the following 2 drug(s):

  • amitriptyline
  • phentermine

Interactions between your selected drugs
  • amitriptyline and phentermine (Moderate Drug-Drug)
MONITOR: The use of tricyclic antidepressants in combination with amphetamines or sympathomimetic appetite suppressants may produce additive cardiovascular effects, increasing the risk of hypertension, cardiac arrhythmias, tachycardia, and fever. The mechanism involves additive pharmacodynamic effects resulting from increased norepinephrine release by sympathomimetic agents and inhibition of norepinephrine reuptake by tricyclic antidepressants. A pharmacokinetic interaction is also possible between tricyclic antidepressants and amphetamines, since many of these agents are metabolized by CYP450 2D6. Increased plasma levels of one or both drugs may occur during coadministration.

MANAGEMENT: Close monitoring of cardiovascular status is recommended for patients receiving this combination. Patients should be advised to promptly report symptoms such as fever, headache, or fast or irregular heartbeats.



thanks for that I will not go ahead with it...better to be safe than sorry...just that with the Amitriptyline I have put six stone in weight on...

now what bothers me is the fact that this anti depressant blocks the feeling of not caring...others around me say I need to lose weight but this medication seems to make me think I am ok...why is this..?
Im on amitriptyline 200mg for about 2 years.i gained weight since then. {details of weight removed} Recently i bought phentermine 37.5 mg 2x daily(sum of 89mg).my doctor doesnt know that im on it when i went to see him yesterday because im having breathing difficulties and my heart rate is quite irregular(mostly its about 115-125 per minute) .i didnt experienced this in the couple days after on develops doctor really thought the rapid heart weight or heart palpitations is because im he gave me 0.5mg of xanax to be taken 4x daily(sum of 2mg).he said it will slow down my heart rate...i want to know wether these problems will go away in days later?

David Baxter PhD

Late Founder
You;'re playing a dangerous game by not informing your doctor about ALL drugs you're taking - whether they are prescription or over-the-counter or recreational street drugs. There some potentially life-threatening drug interactions that can occur when you keep your doctor in the dark.
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