Will eating grapefruit harm me in any way taking qsymia (phentermine and topiramate) ?

Avoid grapefruit: Grapefruit and some other citrous fruits (tangelos & Seville oranges) contain chemicals that inhibit certain enzymes that help your body clear certain medications including one of the two active components of Qsymia (phentermine and topiramate), (phentermine and topiramate) namely topiramate. Grapefruit may thus increase the levels of topiramate in your body and its risks. It is best to avoid eating/drinking grapefruit and its juice while taking Qsymia (phentermine and topiramate).