Nitrofurantoin (Oral)

As an orally administered antibiotic, Nitrofurantoin is an effective treatment for bladder and/or urinary tract infections.


Nitrofurantoin, which is often marketed as Macrobid, is an antibiotic which is specifically used to treat bladder infections and urinary tract infections. It is taken orally. Nitrofurantoin was first made available for use by the public in 1953 and is currently regarded by the World Health Organization as an essential medicine on account of its efficacy and low wholesale cost.

In recent years, the increase of bacterial resistance to certain antibiotics such as trimethoprim and fluoroquinolones has led to an interest in the use of Nitrofurantoin, with several trials demonstrating impressive cure rates for bladder infections and uncomplicated urinary tract infections. Because of this, it has become a front-line agent for the treatment of UTIs and comes recommended by the European Society for Microbiology and Infectious Diseases as well as the Infectious Disease Society of America.

At concentrations achieved within urine, Nitrofurantoin is a bactericide, therefore making it an effective medication in combatting bladder infection. It is useful in fighting against susceptible organisms at concentrations not exceeding 32 ?g/ml. It tends to concentrate in the urine, with the most effective levels of the drug appearing in the urinary tract.

Nitrofurantoin has a complex and unique mechanism of action. It functions by damaging the DNA of bacteria, which is made possible by the rapid reduction of the drug inside bacterial cells by flavoproteins into numerous reactive intermediaries which attack DNA, respiration, ribosomal proteins and other macromolecules present within the cell.

Type Of Medicine

  • Antibiotic

Conditions Treated

  • Bladder infection
  • Urinary tract infection
  • Cystitis
  • E. coli
  • Staphylococcus saprophyticus
  • Streptococcus agalactiae
  • Staphylococcus aureus
  • Enterococcus faecalis
  • Coagulase negative staphylococci

Side Effects

Like many medicines, Nitrofurantoin can cause some unwanted side effects along with its desired effects. The most common side effects reported by patients undergoing treatment with this medicine include the following:

  • Chest pain
  • Chills
  • Changes in facial skin color
  • Coughing
  • General feeling of illness or discomfort
  • Hoarseness
  • Hives
  • Muscle or joint pain
  • Itching
  • Shortness of breath
  • Difficulty swallowing or breathing
  • Swelling of the hands, mouth, feet or face

As the patient continues to take Nitrofurantoin as prescribed by a qualified physician, most (if not all) of the previously mentioned side effects should lessen. If side effects appear to get worse or persist over a prolonged period, the patient is advised to contact their doctor or healthcare provider as soon as possible. In many cases, a doctor or pharmacist will be able to advise on how to alleviate certain symptoms using over the counter remedies or prescription drugs.

Generally, most patients will only experience very minimal side effects while taking Nitrofurantoin - if they experience any whatsoever. Most doctors agree that the benefits of treating urinary tract infections and bladder issues far outweigh the risks of having to experience temporary side effects of mild discomfort.

Other side effects which have been reported rarely, albeit often enough to warrant mentioning, include the following:

  • Blood in the stools or urine
  • Black, tarry stools
  • Dizziness
  • Numbness, tingle, burning or painful sensations
  • Drowsiness
  • Headache
  • Sore throat
  • Pinpoint spots on the skin
  • Awkwardness or unsteadiness
  • Unusual bruising or bleeding
  • Unusual weakness or tiredness
  • Weakness in the legs, hands, arms and feet
  • Blindness
  • Stomach pain
  • Peeling or blistering o the skin
  • Color blindness (particularly with blues and yellows)
  • Cracks in the skin
  • Decreased vision
  • Appetite loss
  • Watery and severe diarrhea
  • Eye pain
  • Loss of body heat
  • Depression
  • Vomiting or nausea
  • Pale stools
  • Pale skin
  • Red lesions on the skin
  • Irritated eyes
  • Swollen skin
  • Scaly, thickened red skin
  • Unpleasant breath odor
  • Wheezing or tightness in the chest
  • Yellow skin or eyes
  • Excess gas
  • Tenderness of the saliva glands
  • Pain in the upper abdomen
  • Ulcers, sores or white spots on the lips/in the mouth
  • Visual changes
  • Light-headedness or dizziness
  • Lack of loss of strength
  • Spinning sensation
  • Uncontrolled eye movements
  • Feeling of constant movement, either of self or surroundings

Because Nitrofurantoin can affect the psychology of the patient, great care should be taken when administering this drug to patients with a history of mental health conditions (such as depression, schizophrenia or bipolar disorder).

This drug can also affect the coordination of the patient. Patients are therefore advised to refrain from driving or operating heavy machinery in the workplace until it has been observed that the patient does not experience side effects of dizziness, visual changes or drowsiness to a degree which causes them any impairment. This is to reduce the risk of serious injury, either to the patient or other road users.

Not all side effects may have been listed. Patients who experience undocumented side effects are advised to inform their doctor or healthcare provider and to report their findings to the FDA.


Like all medicines, it is important that the patient only takes Nitrofurantoin as prescribed by a qualified physician. This means that patients must avoid taking any more of the drug than they have been advised to, either in terms of dose size or frequency. In addition to this, the patient must also stop taking Nitrofurantoin when advised to do so by a doctor, even if they still have a supply of the drug remaining.

Nitrofurantoin should be taken with food, as this helps to improve the absorption rate, and in some instances, tolerance of the drug. However, it can also be taken without food. Dosage will vary according to the individual requirements of the patient, which means it is important for the patient to listen to any instructions when the doctor prescribes this medication. Alternatively, the instructions printed on the side of the packaging can also be followed, as they should be the same or similar to the doctor's recommendations.

The strength of the medication, number of doses each day, time between doses and period of time the patient is to take Nitrofurantoin will all play a part in determining the size of the dose. While the manufacturers provide general dose instructions, it should be reiterated that these are merely guidelines which can be altered at the discretion of the prescribing doctor. Factors discussed between the patient and doctor will play a role in establishing the most effective dose. The doctor will also take into account the age, weight, height and condition of the patient.

Usual adult dose for bladder infection/UTI/cystitis:

The patient should receive 50mg to 100mg of Nitrofurantoin orally, 4 times a day for one week. This dose schedule should be adhered to for at least three days after urine sterility has been obtained. Alternatively, the patient can take 100mg of dual release Nitrofurantoin twice a day for a week.

After the infection is under control, the patient should receive 50mg to 100mg of Nitrofurantoin orally, once per day (typically at bedtime).

Typical pediatric dose for infection:

Patients aged one month or older should receive 5mg to 7mg of Nitrofurantoin per day, orally, divided into four doses. Patients aged over twelve can receive Nitrofurantoin at the same dose as an adult.

After the infection is under control, pediatric patients can be treated with doses as low as 1mg/kg or Nitrofurantoin per day, divided into one or two oral doses.

Patients should not take double doses of this medication. If the patient misses a dose, he or she can simply take the missed dose as soon as they realize. If it is closer to the time for the next dose to be administered, the patient should simply omit the missed dose and take the next dose as per the designated schedule.

Patients who experience signs of overdose (fast or slow heartbeat, difficulty breathing, seizures, loss of coordination and/or flushed skin) may require immediate medical attention. In this instance, the patient or their caregiver should contact their local poison control center on 1800-222-1222 or emergency services on 911.


All drugs have the potential to interact with other drugs or chemicals within the body, and these interactions can cause one or more medicines to become ineffective in treating the conditions they were prescribed to alleviate. In some instances, interactions can cause dangerous and potentially fatal side effects. Because of these risks, the patient is advised to keep a fully detailed list of all medications they are currently taking.

Below is a list of medications known to interact negatively with Nitrofurantoin. Patients who are undergoing treatment with one or more of these medicines are advised to inform their doctor or healthcare provider prior to beginning a course of treatment of Nitrofurantoin:

  • Zalcitabine
  • Zafirlukast
  • Vinorelbine
  • Vincristine Liposome
  • Vincristine
  • Vinblastine
  • Typhoid Vaccine, Live
  • Trospium
  • Trihexyphenidyl
  • Trabectedin
  • Tolterodine
  • Tocilizumab
  • Tinidazole
  • Thioguanine
  • Thalidomide
  • Teriflunomide
  • Teniposide
  • Telbivudine
  • Stavudine
  • Solifenacin
  • Sodium Nitrite/Sodium Thiosulfate
  • Sodium Nitrite
  • Simvastatin/Sitagliptin
  • Simvastatin
  • Secnidazole
  • Scopolamine
  • Rosuvastatin
  • Red Yeast Rice
  • Propantheline
  • Procyclidine
  • Prilocaine
  • Pravastatin
  • Ponatinib
  • Pomalidomide
  • Pitavastatin
  • Phenytoin
  • Peginterferon Beta-1A
  • Peginterferon Alfa-2B
  • Peginterferon Alfa-2A
  • Paclitaxel Protein-Bound
  • Paclitaxel
  • Oxybutynin
  • Oxaliplatin
  • Norfloxacin
  • Niacin/Simvastatin
  • Nelarabine
  • Naltrexone/Oxycodone
  • Naltrexone
  • Mycophenolic Acid
  • Mycophenolate Mofetil
  • Morphine/Naltrexone
  • Mipomersen
  • Metronidazole
  • Methscopolamine/Pseudoephedrine
  • Methscopolamine/Phenylephrine
  • Methscopolamine
  • Methotrexate
  • Mestranol/Norethindrone
  • Mephenytoin
  • Mepenzolate
  • Magnesium Oxide
  • Magnesium Hydroxide/Mineral Oil
  • Magnesium Hydroxide
  • Magnesium Carbonate
  • Magaldrate/Simethicone
  • Magaldrate
  • Lovastatin/Niacin
  • Lovastatin
  • Lomitapide
  • Linezolid
  • Lidocaine/Prilocaine Topical
  • Levodopa
  • Leflunomide
  • Lactobacillus Acidophilus/Methscopolamine
  • Ixazomib
  • Ixabepilone
  • Isoniazid/Rifampin
  • Isoniazid/Pyrazinamide/Rifampin
  • Isoniazid
  • Ipilimumab
  • Iodoquinol
  • Interferon Beta-1B
  • Interferon Beta-1A
  • Interferon Alfa-N1
  • Interferon Alfacon-1
  • Interferon Alfa-2B/Ribavirin
  • Interferon Alfa-2B
  • Interferon Alfa-2A
  • Infliximab
  • Indium Oxyquinoline In-111
  • Idelalisib
  • Hyoscyamine/Phenyltoloxamine
  • Hyoscyamine/Phenobarbital
  • Hyoscyamine/Methenamine/Methylene Blue/Sodium Biphosphate
  • Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate/Sodium Biphosphate
  • Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate
  • Hyoscyamine/Methenamine
  • Hyoscyamine
  • Hydroxychloroquine
  • Hydralazine/Isosorbide Dinitrate
  • Hydralazine/Hydrochlorothiazide/Reserpine
  • Hydralazine/Hydrochlorothiazide
  • Hydralazine
  • Homatropine/Hydrocodone
  • Golimumab
  • Gold Sodium Thiomalate
  • Glycopyrrolate/Indacaterol
  • Glycopyrrolate
  • Fosphenytoin
  • Formoterol/Glycopyrrolate
  • Fluvastatin
  • Fludarabine
  • Fluconazole
  • Flavoxate
  • Ezetimibe/Simvastatin
  • Etravirine
  • Etoposide
  • Ethotoin
  • Ethionamide
  • Ethinyl Estradiol/Norgestrel
  • Ethinyl Estradiol/Norgestimate
  • Ethinyl Estradiol/Norethindrone
  • Ethinyl Estradiol/Norelgestromin
  • Ethinyl Estradiol/Levonorgestrel
  • Ethinyl Estradiol/Folic Acid/Levonorgestrel
  • Ethinyl Estradiol/Etonogestrel
  • Ethinyl Estradiol/Ethynodiol
  • Ethinyl Estradiol
  • Ethambutol
  • Etanercept
  • Eribulin
  • Epirubicin
  • Epinephrine/Prilocaine
  • Elotuzumab
  • Efavirenz/Emtricitabine/Tenofovir
  • Efavirenz
  • Drospirenone/Ethinyl Estradiol/Levomefolate Calcium
  • Drospirenone/Ethinyl Estradiol
  • Docetaxel
  • Disulfiram
  • Didanosine
  • Dicyclomine
  • Dexchlorpheniramine/Methscopolamine/Pseudoephedrine
  • Dexchlorpheniramine/Methscopolamine/Phenylephrine
  • Desogestrel/Ethinyl Estradiol
  • Darifenacin
  • Dapsone Topical
  • Dapsone
  • Crizotinib
  • Colchicine/Probenecid
  • Colchicine
  • Clofarabine
  • Clidinium
  • Citric Acid/Magnesium Oxide/Sodium Picosulfate
  • Citric Acid/Glucono-Delta-Lactone/Magnesium Carbonate Topical
  • Cisplatin
  • Cholera Vaccine, Live
  • Cholecalciferol/Genistein/Zinc Glycinate
  • Cholecalciferol/Genistein/Zinc Chelazome
  • Chlorpheniramine/Methscopolamine/Pseudoephedrine
  • Chlorpheniramine/Methscopolamine/Phenylpropanolamine
  • Chlorpheniramine/Methscopolamine/Phenylephrine/Pseudoephedrine
  • Chlorpheniramine/Methscopolamine/Phenylephrine
  • Chlorpheniramine/Methscopolamine
  • Chlorpheniramine/Guaifenesin/Methscopolamine/Phenylephrine
  • Chlorpheniramine/Dextromethorphan/Methscopolamine
  • Chlorpheniramine/Dextromethorphan/Guaifenesin/Methscopolamine/Phenylephrine
  • Chloroquine
  • Chlordiazepoxide/Methscopolamine
  • Chlordiazepoxide/Clidinium
  • Chloramphenicol
  • Certolizumab
  • Cerivastatin
  • Cellulase/Hyoscyamine/Pancrelipase/Phenyltoloxamine
  • Cascara Sagrada/Magnesium Hydroxide
  • Carfilzomib
  • Carboplatin
  • Carbinoxamine/Methscopolamine/Pseudoephedrine
  • Carbidopa/Levodopa
  • Carbidopa/Entacapone/Levodopa
  • Calcium Carbonate/Magnesium Hydroxide/Simethicone
  • Calcium Carbonate/Magnesium Hydroxide
  • Calcium Carbonate/Magnesium Carbonate
  • Calcium Carbonate/Famotidine/Magnesium Hydroxide
  • Calcium Acetate/Magnesium Carbonate
  • Cabazitaxel
  • Butabarbital/Hyoscyamine/Phenazopyridine
  • Bupropion/Naltrexone
  • Brompheniramine/Chlorpheniramine/Methscopolamine/Phenylephrine/Pseudoephedrine
  • Brentuximab
  • Bortezomib
  • Black Cohosh
  • Bismuth Subsalicylate/Metronidazole/Tetracycline
  • Bismuth Subcitrate Potassium/Metronidazole/Tetracycline
  • Biperiden
  • Benztropine
  • Benzoic Acid/Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate
  • Benznidazole
  • Belladonna/Opium
  • Belladonna/Ergotamine/Phenobarbital
  • Belladonna/Caffeine/Ergotamine/Pentobarbital
  • Belladonna/Butabarbital
  • Belladonna
  • Bedaquiline
  • Balsalazide
  • Aurothioglucose
  • Auranofin
  • Atropine/Pralidoxime
  • Atropine/Phenobarbital
  • Atropine/Hyoscyamine/Phenobarbital/Scopolamine
  • Atropine/Edrophonium
  • Atropine/Diphenoxylate
  • Atropine/Difenoxin
  • Atropine/Chlorpheniramine/Hyoscyamine/Pseudoephedrine/Scopolamine
  • Atropine/Chlorpheniramine/Hyoscyamine/Phenylephrine/Scopolamine
  • Atropine/Chlorpheniramine/Hyoscyamine/Phenylephrine/Phenylpropanolamine/Scopolamine
  • Atropine
  • Atorvastatin/Ezetimibe
  • Atorvastatin
  • Aspirin/Pravastatin
  • Amylase/Cellulase/Hyoscyamine/Lipase/Phenyltoloxamine/Protease
  • Amyl Nitrite/Sodium Nitrite/Sodium Thiosulfate
  • Amlodipine/Atorvastatin
  • Amiodarone
  • Aluminum Hydroxide/Magnesium Trisilicate
  • Aluminum Hydroxide/Magnesium Hydroxide/Simethicone
  • Aluminum Hydroxide/Magnesium Hydroxide
  • Aluminum Hydroxide/Magnesium Carbonate
  • Aluminum Hydroxide/Diphenhydramine/Lidocaine/Magnesium Hydroxide/Simethicone Topical
  • Aluminum Hydroxide/Calcium Carbonate/Magnesium Hydroxide/Simethicone
  • Aluminum Hydroxide/Aspirin/Calcium Carbonate/Magnesium Hydroxide
  • Alginic Acid/Aluminum Hydroxide/Magnesium Trisilicate
  • Alginic Acid/Aluminum Hydroxide/Magnesium Carbonate
  • Ado-Trastuzumab Emtansine
  • Adalimumab
  • Acetaminophen/Aluminum Hydroxide/Aspirin/Caffeine/Magnesium Hydroxide


Patients who are allergic to this medication should not use it. Patients who have one or more of the following conditions should avoid Nitrofurantoin:

  • Severe kidney disease
  • Jaundice
  • A history of liver problems
  • Urinating less than usual, or not at all
  • In the last month of pregnancy

To ensure that Nitrofurantoin is safe to use, patients should inform their doctors if they have any of the following:

  • Diabetes
  • Anemia
  • Kidney disease
  • Electrolyte imbalance
  • Vitamin B deficiency
  • G6PD deficiency
  • Any type of debilitating disease

The patient must ensure that they take this medicine for the full prescribed length of time. Symptoms of infection may improve or disappear completely before the infection has been completely cleared. If the patient stops taking this medication abruptly, the possibility of the infection recurring is hugely increased. It is therefore in the patient's best interests to complete the full course of treatment with Nitrofurantoin. It is typically given for up to three days after laboratory tests have demonstrated that the infection has cleared.

Patients who use Nitrofurantoin for long periods of time may require frequent medical tests at their doctor's office. Nitrofurantoin can also cause unusual results in certain lab tests for glucose within the urine, which can cause a false-positive reading for diabetes.

Certain antibiotics, including Nitrofurantoin, can cause diarrhea which can be a sign or symptom of a new infection. If the patient experiences diarrhea which is watery or contains blood, they should contact their doctor as soon as possible.


Nitrofurantoin should be kept in the packaging it was shipped in. It should be stored at room temperature, away from sources of moisture, heat and light. It is therefore unsuitable for storage in a bathroom cabinet and should instead be kept away from reach of children and/or pets in a dedicated medicine cupboard.

Patients who need to dispose of unwanted, unused or expired Nitrofurantoin should do so in accordance with state law and FDA guidelines. Many pharmacies offer "take back"programs, where they will recycle or dispose of unwanted medications, often for free. Patients with unused medicines are advised to take advantage of such programs, instead of flushing medicines down the toilet or drain.


Nitrofurantoin is a greatly beneficial drug, although it can pose a risk to patients who do not communicate effectively with their doctors. As a treatment designed to alleviate the symptoms of bladder and urinary tract infections, Nitrofurantoin helps to fight off bacteria and is transported in the urine.

However, this drug can also affect how the body reacts to stimuli and can cause unwanted dizziness, loss of coordination and changes in vision which can impair the day-to-day functioning of the patient, and in some instances, this can cause the patient to end up in perilous situations. It is therefore important for the patient to be upfront and honest about their medical history to rule out any potential complications.

When taken correctly, Nitrofurantoin helps to provide relief of severe bladder and urinary tract infection. To achieve this, patient and doctor must work together to ascertain the most appropriate dose size and frequency.