Drug Interactions between allopurinol and Diltiazem Hydrochloride XR

Allopurinol should generally be taken after a meal to reduce side effects. If your daily dose exceeds 300 mg, you may also ask your healthcare provider if it is okay to divide the total daily dose into smaller doses given more frequently instead of once a day, as this may also reduce stomach upset that can happen with allopurinol. It is best to avoid or limit the consumption of alcohol, as it can increase drowsiness or other nervous system side effects of allopurinol. You should also avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. 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.

Alcohol can lower your blood pressure and add to the effects of dilTIAZem. You may experience dizziness, lightheadedness, fainting, or a rapid heartbeat if you drink alcohol with dilTIAZem, especially when you first start taking the medication or just after a dose increase. Grapefruit juice may also increase the effects of dilTIAZem in some people by increasing its levels in the blood. You may want to limit alcohol intake and avoid excessive consumption of grapefruit and grapefruit juice during treatment with dilTIAZem. However, if you have been regularly consuming grapefruit or grapefruit juice with dilTIAZem, do not alter the amounts of these products in your diet without first talking to your doctor or other healthcare professional. Contact your doctor if your condition changes or you experience increased side effects of dilTIAZem such as headache, irregular heartbeat, swelling, unexplained weight gain, or chest pain. Orange juice is not expected to interact.

Using dilTIAZem together with multivitamin with minerals can decrease the effects of dilTIAZem. Talk with your doctor before using dilTIAZem and multivitamin with minerals together. You may need a dose adjustment or need your blood pressure checked more often if you take 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.