Methenamine Side Effects and Warnings

What are the precautions when taking this medicine?

• If you are allergic to tartrazine, talk with healthcare provider. Some products contain tartrazine.

• If you have liver disease, talk with healthcare provider.

• Check medicines with healthcare provider. This medicine may not mix well with other medicines.

• Do not take aspirin, antacids or medicines that raise the pH of the urine while on this medicine.

• Avoid citrus fruits, dairy products, and certain vegetables while taking this medicine.

• Certain water pills may decrease the effects of this medicine. Talk with healthcare provider.

• Tell healthcare provider if you are pregnant or plan on getting pregnant.

• Tell healthcare provider if you are breast-feeding.

What are some possible side effects of this medicine?

• Nausea or vomiting. Small frequent meals, frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.

• Bladder or urination pain or change in urination frequency.

Reasons to call healthcare provider immediately

• If you suspect an overdose, call your local poison control center or emergency department immediately.

• Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.

• Severe nausea or vomiting.

• Severe diarrhea, even after medicine is stopped.

• Any rash.

• No improvement in condition or feeling worse.