Nitrofurantoin: Uses and Side Effects

It is a prescription medicine used to treat and prevent urinary tract infections (UTIs).

It is sold under the brand names Furadantin®, Macrobid®, and Macrodantin®. Nitrofurantoin works uniquely compared to other antibiotics.

The drug changes to a highly reactive form in bacterial cells that destroys specific bacterial proteins and molecules.

Possible side effects of Nitrofurantoin include vomiting, nausea, and loss of appetite. However, most people tolerate it well; they tend to be mild and easy to treat if side effects occur.

To help ensure a safe treatment process, the doctor will ask you several questions about your current medications and the diseases you have before you start treatment, especially if you have diabetes, anemia, or kidney disease.

How does this medication work?

Nitrofurantoin works uniquely, compared to other antibiotics. In bacterial cells, the drug changes to a highly reactive form that destroys certain bacterial proteins and molecules.

As a result, the drug interferes with the ability of bacteria to make essential cellular components, such as proteins, DNA, and cell walls.


When and how is it used?

The medicine comes in liquid form or capsules. The liquid tablets, Macrodantin and Furadantin, are usually taken as prescribed by the doctor. However, they can be taken only once a day to prevent long-term Urinary Infections (UTIs).

Macrobid capsules are usually taken twice a day. Nitrofurantoin should be taken with food since the absorption of this antibiotic is increased.

It does not matter what times of the day this medication is taken. However, it is advisable to try to space the doses evenly. For the medication to work correctly, it must be taken as directed by the doctor or specialist.

Nitrofurantoin will not work correctly if you stop taking it too soon.

What should I do if I miss a dose?

If you do not take the dose as scheduled, take it as soon as possible. However, if it is almost time for the next dose, skip the one you forgot and continue with your regular schedule.

Do not take a double dose. Because this medication is an antibiotic, it is essential not to lose any amounts.


The dose of Nitrofurantoin (Furadantin®, Macrobid®, Macrodantin®) will vary according to the medical professional depending on several factors, such as:

  • The product in particular.
  • Your age.
  • Your weight (for children).
  • Either you are taking this medication to treat or to prevent bladder infections.

Dosage of Nitrofurantoin for Macrodanthin and Furadantin

Furadantin (liquid form) and Macrodantin (the state of the regular capsule) are usually taken four times a day for the treatment of urinary tract infections (UTI) or once a day to prevent them.

The recommended dose for treating Nitrofurantoin IU in adults is 50 to 100 mg four times a day, continued for at least three days after the infection has disappeared.

For uncomplicated infections, the lowest amount is usually recommended. For long-term treatment to prevent urinary tract infections in adults, a dose of 50 or 100 mg once a day at bedtime is usually enough.

The recommended dose of Nitrofurantoin for treating urinary tract infections in children (between one month and older) is based on body weight.

As a result, it is best for your child’s doctor to weigh it to determine an exact dosage, especially if your child has not been considered recently.

To treat bladder infections, Nitrofurantoin is usually given four times a day. The medicine is given once or twice a day to prevent bladder infections in children.

Most common side effects

  • Sickness.
  • Vomiting
  • Loss of appetite
  • Stomach ache.
  • Diarrhea.
  • Pain in the hands and feet.
  • Weakness.
  • Dizziness.
  • Headache.
  • Drowsiness.

If these effects are mild, they may disappear after a few days or weeks. If they are more severe or do not go away, talk to your doctor or pharmacist.

Serious side effects

Inflammation of the lungs Symptoms may include:

  • Fatigue.
  • Short of breath.
  • Fever.
  • Cold.
  • Tos.
  • Chest pain.
  • Liver problems Symptoms may include:
  • Itch.
  • Yellowing of the skin or the white part of your eyes. Nausea or vomiting.
  • Dark urine.
  • Loss of appetite
  • Damage to the nerve Symptoms may include:
    • Numbness or tingling in the hands and feet.
    • Muscular weakness.
  • Hemolysis (damage of red blood cells). Symptoms may include:
    • Fatigue.
    • Weakness.
    • Pale skin.

Precautions and warnings

Severe lung problems have occurred in people taking Nitrofurantoin, the active ingredient in Furadantin, Macrobid, and Macrodantin. Such issues are rare but are more common in people who take the medication for six months or longer.

People who take this medication in the long term should have their lungs monitored carefully. Be sure to report any pulmonary symptoms, such as shortness of breath or unexplained cough, to your doctor immediately.

Nitrofurantoin can cause nerve problems, which can be pretty serious. Check with your doctor if you experience any unusual sensations (burning, numbness, or tingling), especially in the hands or feet.

People with kidney failure, anemia, diabetes, an electrolyte imbalance, or a vitamin B deficiency may be more likely to experience these types of nerve problems.

In rare cases, people who take Nitrofurantoin have experienced liver damage, including fatal liver problems. If you take this medication in the long term (or often), your doctor may want to control your liver function.

People who take this drug in the long term should have their kidney function checked periodically (by a simple blood test).

There have been cases of hemolytic anemia (destruction of red blood cells) linked to Nitrofurantoin, especially in people with deficiency of glucose-6-phosphate dehydrogenase.

Nitrofurantoin is considered a Category B pregnancy medicine. This means that it is likely to be safe for use during pregnancy; despite everything, the risks are currently unknown.

However, this medication is not recommended for women nearing the end of pregnancy. Many antibiotics have been known to cause pseudomembranous colitis (severe diarrhea).

This is a severe condition that can be life-threatening. If you have brutal, bloody, or prolonged diarrhea, contact your doctor immediately.

Nitrofurantoin passes through breast milk in small amounts. Therefore, if you are breastfeeding, check with your doctor before taking this medication.