-acetazolamide
-antacids
-aspirin
-choline salicylate
-certain antibiotics like sulfacetamide and sulfamethoxazole
-certain medicines for blood pressure like hydrochlorothiazide
-fludrocortisone
-hydrocortisone
-magnesium salicylate
-methazolamide
-sodium bicarbonate
-topiramate

They need to know if you have any of these conditions:

-dehydration
-heart disease
-high blood pressure
-high levels of phosphate in the blood
-high levels of sodium in the blood
-history of pancreatitis
-kidney disease
-liver disease
-parathyroid disease
-sodium (salt) restricted diet
-an unusual or allergic reaction to methenamine; sodium acid phosphate, other medicines, foods, dyes, or preservatives
-pregnant or trying to get pregnant
-breast-feeding

Tell your doctor or healthcare professional if your symptoms do not start to get better or if they get worse.

Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you.

You may need to be on a special diet while taking this medicine. Ask your health care professional how many glasses of water or other fluids to drink each day. Also, ask which foods to include and which to avoid to help keep your urine acidic. Your urine must be acidic for this medicine to work.

Keep out of the reach of children.

Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F). Throw away any unused medicine after the expiration date. Protect from light.