Go to home page

Furadantin Prescribing Information

Furadantin, also known by its generic name nitrofurantoin, is an antibiotic medication commonly used to treat urinary tract infections (UTIs). It belongs to a class of drugs called nitrofuran antibiotics. Furadantin works by interfering with the growth and reproduction of bacteria, making it effective against various types of bacteria that can cause UTIs.

It is often prescribed for uncomplicated lower urinary tract infections, such as those caused by Escherichia coli and other susceptible bacteria. However, it might not be effective against all types of bacterial infections, and its use should be based on the specific bacteria causing the infection and its susceptibility to nitrofurantoin.

Furadantin tablets

Uses of Furadantin

Furadantin is primarily used to treat urinary tract infections (UTIs), especially those caused by susceptible bacteria. Its main role is in treating uncomplicated lower UTIs. Here are the common uses:

  • Urinary Tract Infections (UTIs): Medicine is commonly prescribed to treat bacterial infections of the urinary tract, including infections of the bladder (cystitis) and infections of the urethra (urethritis). It is effective against various bacteria, particularly Escherichia coli, which is a common cause of UTIs.
  • Prophylaxis for Recurrent UTIs: In some cases, Furadantin may be used as a prophylactic (preventive) treatment for individuals who experience recurrent urinary tract infections. It can help prevent the recurrence of UTIs by suppressing the growth of bacteria in the urinary tract.
  • Other Infections: While Furadantin is primarily used for UTIs, it might be used in some cases for other types of bacterial infections if the causative bacteria are susceptible to nitrofurantoin. However, its use is generally limited to urinary tract infections due to its specific mechanism of action and spectrum of activity.


Furadantin is typically available in different formulations, such as capsules and oral suspension. The dosage of Nitrofurantoin can vary based on the specific formulation, the severity of the infection, the patient's age, and other individual factors. It's important to follow the dosing information on the prescription label. Here are some general guidelines for dosages:

Furadantin Capsules (Macrocrystals):

  • For Uncomplicated Lower UTIs: The typical adult dose is 100 mg taken orally twice a day (every 12 hours) for 7 days.
  • For Prophylaxis: The usual adult dose is 50 to 100 mg taken orally at bedtime.
  • Pediatric doses for children over 12 years old are typically similar to adult doses. Children under 12 years old generally have weight-based dosing.

Furadantin Oral Suspension (Macrocrystals):

  • The dosage for adults and children over 12 years old is similar to the capsule dosage.
  • Pediatric doses for children under 12 years old are typically weight-based and may vary depending on the child's age and weight.
  • It's important to note that Furadantin should be taken with food or milk to enhance absorption and reduce the likelihood of stomach upset.

Side Effects of Furadantin

Furadantin can cause side effects in some individuals. Not everyone will experience these side effects, and their severity can vary. Common side effects may include:

Gastrointestinal Effects:

  • Nausea
  • Vomiting
  • Diarrhea
  • Upset stomach
  • Loss of appetite

Central Nervous System Effects:

  • Headache
  • Dizziness

Respiratory Effects (Rare):

  • Pulmonary reactions, such as acute and subacute lung injury

Allergic Reactions (Rare):

  • Skin rash
  • Itching
  • Swelling (angioedema)
  • Fever

Other Possible Side Effects:

  • Brownish discoloration of urine (harmless side effect due to the medication's color)
  • Hemolytic anemia (rare)

It's important to note that some of these side effects, such as acute lung injury and hemolytic anemia, are relatively rare but can be serious.

Additionally, Furadantin should be used with caution in patients with impaired kidney function, as the medication is primarily excreted through the kidneys. Dosage adjustments may be necessary in individuals with kidney problems to prevent the accumulation of the medication in the body.

Interaction with other drugs

Furadantin can interact with other drugs, potentially affecting how the medications work or increasing the risk of side effects. It's important to inform your healthcare provider about all the medications, supplements, and herbal products you are taking before starting Furadantin. Here are some examples of drug interactions to be aware of:

  • Antacids Containing Magnesium Trisilicate: Taking antacids that contain magnesium trisilicate can reduce the absorption of Nitrofurantoin, making it less effective. It's recommended to avoid taking these antacids within two hours of Furadantin.
  • Probenecid: Probenecid, a medication used to treat gout, can decrease the elimination of Furadantin from the body, potentially leading to increased levels of the antibiotic in the blood. This could increase the risk of side effects.
  • Sulfinpyrazone: Similar to probenecid, sulfinpyrazone, another medication for gout, can also interfere with the elimination of Furadantin and increase its levels in the blood.
  • Other Antibiotics: Concurrent use of other antibiotics, especially those with potential kidney toxicity, can increase the risk of kidney damage when used with Furadantin.
  • Medications that Affect Kidney Function: Drugs that affect kidney function can impact the elimination of Furadantin from the body.
  • Methotrexate: Furadantin might decrease the elimination of methotrexate from the body, potentially increasing the levels of methotrexate and its associated side effects.
  • Other Drugs: Various other medications can interact with Furadantin, including certain blood thinners, certain diabetes medications, and more.

What to avoid while on Furadantin

While taking Furadantin, there are certain things you should avoid to ensure the effectiveness of the medication and to minimize the risk of potential side effects. Here are some important considerations:

  • Alcohol: It's generally recommended to avoid alcohol while taking antibiotics. Alcohol can interact with medications and potentially increase the risk of side effects or reduce the effectiveness of the antibiotic.
  • Antacids: Antacids containing magnesium trisilicate can interfere with the absorption of Nitrofurantoin. If you need to take an antacid for stomach discomfort, do so at least two hours before or after taking Furadantin.
  • Supplements and Herbal Products: Certain supplements and herbal products can interact with medications.
  • Other Medications: Some medications can interact with Furadantin, affecting its effectiveness or increasing the risk of side effects.
  • Sun Exposure: While there's no direct evidence of Furadantin causing photosensitivity, it's always a good practice to use sun protection measures, such as sunscreen and protective clothing, when spending time outdoors. Some medications can increase sensitivity to sunlight.
  • Driving and Operating Machinery: Some people might experience dizziness or other central nervous system effects while taking this drug. If you experience these effects, it's best to avoid activities that require alertness, such as driving or operating heavy machinery.
  • Kidney-Affecting Substances: Antibiotic is eliminated from the body primarily through the kidneys. To avoid putting excess stress on your kidneys, it's a good idea to stay hydrated, avoid excessive caffeine and alcohol.
  • Unnecessary Antibiotic Use: Avoid using antibiotics for conditions they are not intended to treat, as unnecessary antibiotic use contributes to antibiotic resistance.
  • Smoking: While there's no specific interaction between Furadantin and smoking, smoking can affect overall health, including the respiratory system. If you have a respiratory condition, it's advisable to avoid smoking.

Contraindications of Furadantin

Furadantin has certain contraindications, which are specific situations or conditions where the medication should not be used due to the potential risks and lack of benefits. Here are some contraindications:

  • Severe Kidney Impairment (CrCl ‹ 60 mL/min): Antibiotic is primarily eliminated from the body through the kidneys. If you have severe kidney impairment (a creatinine clearance, or CrCl, of less than 60 mL/min), the medication's clearance from your body may be significantly reduced, leading to a risk of toxicity.
  • Anuria, Oliguria, or Significant Renal Dysfunction: Anuria refers to the absence of urine production, while oliguria is a significantly reduced urine output. Furadantin may not be suitable for individuals with these conditions, as the drug relies on urinary elimination for its action and elimination.
  • G6PD Deficiency: People with glucose-6-phosphate dehydrogenase (G6PD) deficiency are at an increased risk of developing hemolytic anemia when exposed to certain drugs, including nitrofurantoin. Furadantin should be avoided in individuals with G6PD deficiency.
  • Hypersensitivity or Allergic Reaction to Nitrofurantoin: If you have experienced a hypersensitivity or allergic reaction to nitrofurantoin in the past, you should not take Furadantin. Allergic reactions can range from mild skin rashes to severe anaphylactic reactions.
  • Pregnancy at Term (38 to 42 Weeks): Due to the potential risk of hemolytic anemia in newborns, Furadantin should not be used at term (from 38 to 42 weeks of pregnancy) when labor is about to begin, as the medication can affect the newborn's red blood cells.
  • Infants Under 1 Month of Age: Furadantin is generally not recommended for infants under the age of one month due to the risk of neonatal hemolytic anemia.
  • Labor and Delivery: Furadantin is not recommended for use during labor and delivery or when there is a risk of premature delivery. This is to avoid potential effects on the newborn's red blood cells.
  • Severe Liver Impairment: While liver impairment is not a common contraindication, severe liver impairment may affect the metabolism and elimination of Furadantin.

Pregnancy and Furadantin

Furadantin use during pregnancy requires careful consideration due to potential risks to both the pregnant individual and the developing fetus. Here's what you should know about using this medicament during pregnancy:

  • First Trimester: There has been historical concern about using nitrofurantoin during the first trimester of pregnancy due to a theoretical risk of birth defects. However, more recent studies have not consistently shown a significant association between nitrofurantoin and birth defects when used during the first trimester.
  • Second and Third Trimesters: Nitrofurantoin is generally considered safer to use during the second and third trimesters of pregnancy. It's often recommended as an option for treating urinary tract infections in pregnant individuals if the benefits outweigh the potential risks.
  • Fetal Hemolytic Anemia: There is a risk of causing hemolytic anemia in newborns, especially if nitrofurantoin is used near term (from 38 to 42 weeks of pregnancy). This is due to the medication's potential to affect the newborn's red blood cells.
  • Glucose-6-Phosphate Dehydrogenase (G6PD) Deficiency: Pregnant individuals with G6PD deficiency are at an increased risk of developing hemolytic anemia in response to nitrofurantoin. This is important to consider when assessing the use of Furadantin during pregnancy.
  • Preterm Labor: Nitrofurantoin is generally avoided near term (when labor is about to begin) and in cases of risk of premature delivery due to concerns about its effects on the newborn's red blood cells.
Drug Uses

» Drug Uses (format pdf, 0.2 Mb)

Move On Top