Drug Interactions between Benadryl and dipyridamole

Caffeine may interfere with the effects of dipyridamole in dilating the arteries. You should avoid caffeine-containing products for at least 24 hours before an imaging procedure involving dipyridamole given by injection. However, no special precaution is necessary if you are taking dipyridamole orally for maintenance.

Ask your doctor before using diphenhydrAMINE together with ethanol (alcohol). Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking diphenhydrAMINE. You should be warned not to exceed recommended dosages and to avoid activities requiring mental alertness. If your doctor prescribes these medications together, you may need a dose adjustment to safely take this combination. 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.

Ask your doctor before using dipyridamole together with caffeine. Using these medications together can decrease the effects of dipyridamole. It is recommended that caffeine including caffeine be avoided for 12 to 24 hours before dipyridamole administration. You may need a dose adjustment or special test if you use both medications. 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.