Indications 

Hiprex is a prescription medication used to prevent or reduce the frequency of recurring urinary tract infections when long-term treatment is necessary.  

This medication should only be used after the infection has been cleared by other suitable antimicrobial agents. 

Hiprex is classified as an anti-infective medication that inhibits bacterial growth and acidifies the urine. It functions by converting methenamine to formaldehyde in acidic urine, which kills bacteria.  

Hiprex solely treats bacterial infections in the urinary tract and is ineffective against other bacterial or viral infections. Misuse or overuse of this medication or any antibacterial drug can result in reduced effectiveness. 

Uses and Dosage 

Before starting treatment with Hiprex and every time you get a refill, thoroughly review its patient information leaflet and medication guide. Seek guidance from a physician or pharmacist if any concerns or inquiries arise. 

The dosage of Hiprex may vary per individual based on their medical condition and response to the treatment. Age and weight are also considered for pediatric patients.  

Typically, adults are prescribed to take 1 tablet of Hiprex twice daily without regard to food intake. While children over 6 years old are recommended to take half to 1 tablet twice daily without regard to food intake as well.  

To enhance Hiprex’s efficacy, more acidic urine is preferred. Your doctor may evaluate your urine’s acidity level (urine pH) and suggest ways to raise it, such as taking vitamin C or drinking cranberry juice, avoiding alkaline-producing foods, and modifying alkalinizing drugs. 

Follow your doctor’s advice and take Hiprex exactly how it is prescribed. Avoid taking more or less of it or taking it more frequently than instructed by your doctor. 

For the best result, take Hiprex regularly at the same time(s) daily, with evenly spaced intervals. 

Continue taking this medication for the entire prescribed duration, even if you feel better. Omitting doses or terminating the treatment prematurely can foster the growth of bacteria, resulting in infection recurrence and potentially contributing to bacterial resistance, making the infection harder to treat. 

Side Effects 

Potential side effects associated with the use of Hiprex are listed below. If any of them persists or worsens, promptly inform your physician or pharmacist. 

Common Side Effects 

• Painful urination 
• Nausea and vomiting 
• Rash and itching 

Serious Side Effects 

• Increased urination 
• Painful urination 
• Blood in urine 
• Swelling and shortness of breath 

Allergic Reactions 

While it is uncommon, a severe allergic reaction to Hiprex can occur. Seek medical assistance immediately if you experience symptoms such as: 

• Rash 
• Swelling or itching, especially in the areas of the face, tongue, or throat 
• Severe dizziness 
• Difficulty breathing 

The side effects of Hiprex listed here are incomplete. If any unmentioned side effects occur and cause discomfort, notify your physician promptly. 

Cautions 

Before taking Hiprex, inform your physician or pharmacist if you have any known hypersensitivities, especially to methenamine, aspirin, tartrazine (a yellow dye present in some processed foods and drugs), or any other medications. 

This medication may also contain inactive ingredients that can trigger allergic reactions or other complications. Consult your pharmacist for more information. 

To ascertain the safety of Hiprex for you, disclose your medical history to your doctor, especially of: 

• Kidney problems 
• Liver problems 
• Dehydration 

Hiprex may interact with certain products, such as: 

• Sulfonamide drugs (e.g., sulfamethizole) 
• Urinary alkalinizers that reduce the amount of acid in the urine (e.g., antacids, sodium bicarbonate, potassium, or sodium citrate) 
• Carbonic anhydrase inhibitors (e.g., acetazolamide) 

To prevent such drug interactions, notify your physician and pharmacist of all medications, whether prescription or non-prescription, as well as any vitamins, supplements, or herbal products that you are taking. 

Before undergoing any laboratory tests, inform laboratory personnel and all medical professionals involved in your care that you are taking Hiprex. This is because this medication may interfere with certain laboratory tests and lead to inaccurate or false test results. 

The safety of Hiprex has not been established during early pregnancy, while its use during the last trimester is suggested but unconfirmed. The use of Hiprex during pregnancy should only be when necessary and after discussing the risks and benefits with your doctor.  

Methenamine can transfer into breast milk, but its impact on a nursing infant remains uncertain. Consult your physician before breastfeeding.