Can you take Phentermine while taking diclofenac?

Phentermine may diminish the antihypertensive effect of Diovan. Amphetamines, like phentermine, are known to cause modest increases in average blood pressure and heart rate. The benefits of combined use of these two medications usually outweigh the risks. Timing and dosage play a factor in the interaction of the two. You should talk to your doctor if you have any concerns.