Nitrofurantoin, Macrocrystals (nye-troe-fure-AN-toyn MAK-roe-kris-tals)
Treats urinary tract infections caused by bacteria. This medicine is an antibiotic.
There may be other brand names for this medicine.
When This Medicine Should Not Be Used
You should not use this medicine if you have had an allergic reaction to nitrofurantoin or if you are in your last weeks of pregnancy (week 38 or later). You should not use this medicine if you have severe kidney disease, if you are unable to urinate, or if you have a decreased amount of urine. Do not use this medicine if you have a history of liver disease with nitrofurantoin.
How to Use This Medicine
- Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.
- It is best to take this medicine with food or milk.
- Keep using this medicine for the full treatment time, even if you feel better after the first few doses. Your infection may not clear up if you stop using the medicine too soon.
If a dose is missed:
- If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.
How to Store and Dispose of This Medicine
- Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
- Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
- Keep all medicine away from children and never share your medicine with anyone.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Make sure your doctor knows if you are also using probenecid (Benemid®) or sulfinpyrazone (Anturane®).
- It is best not to use antacids containing magnesium trisilicate (such as Foamicon® or Gaviscon®) while you are using nitrofurantoin.
Warnings While Using This Medicine
- Make sure your doctor knows if you are pregnant or breastfeeding, or if you have liver disease, heart disease, lung disease, anemia, diabetes, a mineral imbalance in the blood, or vitamin B deficiency. Make sure your doctor knows if you have a condition called G6PD-deficiency.
- This medicine may cause your urine to be a brown color. This is normal and will not affect how the medicine works.
- If you have severe diarrhea, ask your doctor before taking any medicine to stop the diarrhea.
- Use this medicine only to treat the infection you now have. This medicine will not work for colds, flu, or other virus infections.
- If you take this medicine to prevent a urine infection, you may take it for a long time. Your doctor will need to check your blood or urine at regular visits while you are using this medicine. Be sure to keep all appointments.
Possible Side Effects While Using This Medicine
Call your doctor right away if you notice any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Blisters, peeling, or red skin rash.
- Cough, fever, chills, weakness, shortness of breath, or chest pain.
- Dark-colored urine or pale stools.
- Diarrhea or loose, watery stools that may contain blood.
- Nausea, vomiting, loss of appetite, or pain in your upper stomach.
- Numbness, tingling, or burning pain in your hands, arms, legs, or feet.
- Yellowing of your skin or the whites of your eyes.
If you notice these less serious side effects, talk with your doctor:
- Dizziness, headache, or blurred vision.
- Hair loss.
- Mild nausea, vomiting, constipation, stomach upset, or pain.
- Vaginal itching or fluids.