Drug Interaction Report

Calcium carbonate may reduce the effectiveness of methenamine in treating your condition. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely 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.

Calcium absorption may be increased by taking it with food. However, foods high in oxalic acid (spinach or rhubarb), or phytic acid (bran and whole grains) may decrease calcium absorption. Calcium may be taken with food to increase absorption. Consider spacing calcium administration for at least 2 hours before or after consuming foods high in oxalic acid or phytic acid. Talk to your doctor if you have any questions or concerns. 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.