Drug Interaction Report

Halofantrine may increase the blood levels and effects of fesoterodine. You may need a dose adjustment if you have been taking fesoterodine and are starting treatment with halofantrine. Let your doctor know if you experience excessive drowsiness, dizziness, irregular heartbeat, blurry vision, difficulty urinating, dry mouth, headache, gastrointestinal upset, or constipation while taking these medications, as they may be symptoms caused by excessive effects of fesoterodine. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

You may experience reduced absorption of halofantrine in the presence of food. Halofantrine should be taken on an empty stomach at least 1 hour before or 2 hours after food. This will make it easier for your body to absorb the medication. Also, while taking halofantrine, you should avoid grapefruits and grapefruit juice. Grapefruit can raise the levels of halofantrine in your body and lead to increased adverse effects. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Grapefruit juice may increase the levels of fesoterodine in your body. Let your doctor know if you experience excessive drowsiness, dizziness, irregular heartbeat, blurry vision, difficulty urinating, dry mouth, headache, gastrointestinal upset, or constipation while taking fesoterodine. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.