Methenamine - Oral

Methenamine is used to treat or prevent bacterial infections of the urinary tract, which includes the bladder or urethra (a tube that allows passage of urine from the bladder and out of the body).

Take Methenamine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

Ask your doctor or pharmacist whether you should take this medicine with or without food. Different preparations of this medicine may be taken differently. Try to take it at the same time each day.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the type and severity of your infection.

Take Methenamine at regular intervals. Do not skip any doses. You must complete the entire course of this medicine. If you don't, the infection will not be properly controlled.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.

Do not take Methenamine if you ever had an allergic reaction (e.g. rashes, breathlessness, swollen eyes) to this medicine or any of its ingredients.

Alert your doctor if you have the following conditions:

• gout (high uric acid level in the blood)
• metabolic acidosis (a condition when there is too much acid in the blood)
• severe dehydration (excessive water loss from the body)
• kidney disease
• liver disease

as this medicine may not be suitable for you.

Do not take Methenamine with a certain group of medicines called sulfonamides.

Let your doctor know if you are pregnant or breastfeeding.

Be sure to check with your doctor or pharmacist before giving Methenamine to a child. Children may be more sensitive to the side effects.

For as long as you are taking this medicine, you may need to have regular tests (e.g. liver function or urine test) to check your body's response to the medicine. Your doctor will advise you about how often you need to have these tests.

Methenamine may cause any of the following side effects: nausea, vomiting, diarrhoea, abdominal pain, itchy skin, and rash.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:

• blood in the urine
• pain or difficulty in passing urine, bladder pain, change in how much urine is passed

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.

Do not take Methenamine with a certain group of medicines called sulfonamides.

Inform your doctor and pharmacist if you are taking antacids (medicines that neutralise stomach acids).

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements, and medicines that you buy without a prescription.

Avoid alcohol.

Avoid foods that may affect the acidity of your urine. Ask your doctor or dietitian about the types of food you should avoid.

Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.