Dorzolamide and timolol and Phentermine and topiramate interaction
Dorzolamide and timolol and Phentermine and topiramate: the Phentermine and topiramate prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Phentermine and topiramate label · effective 2026-05-18
Avoid use of phentermine and topiramate extended-release capsules with other carbonic anhydrase inhibitors.
If concomitant use of phentermine and topiramate extended-release capsules with another carbonic anhydrase inhibitor is unavoidable, the patient should be monitored for the appearance or worsening of metabolic acidosis.
Concomitant use of phentermine and topiramate extended-release capsules and a carbonic anhydrase inhibitor may increase the severity of metabolic acidosis and may also increase the risk of kidney stone formation [see Warnings and Precautions (5.10) ] .
Carbonic Anhydrase Inhibitors Clinical Impact Concomitant use of topiramate with any other carbonic anhydrase inhibitor may increase the severity of metabolic acidosis and may also increase the risk of kidney stone formation.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.