Written by Medicover Team and Medically Reviewed by Dr Badal Shivnarayan Taori, General Medicine

Understanding Nitrofurantoin 100mg: Uses and Side Effects

Nitrofurantoin is a commonly prescribed antibiotic used to treat urinary tract infections (UTIs). This article will explore the uses, side effects, interactions, and other essential information about Nitrofurantoin 100 mg.

What is Nitrofurantoin 100 mg Tablet?

Nitrofurantoin is an antibiotic in the nitrofuran class. It kills bacteria or prevents their growth. Nitrofurantoin 100 mg is a standard dosage form used to treat and prevent certain types of UTIs.

What are the Uses of Nitrofurantoin 100 mg?

Nitrofurantoin 100 mg is an antibiotic primarily used to treat and prevent urinary tract infections (UTIs). It is effective against specific bacteria and concentrated in the urine, making it ideal for bladder infections. Below are its key uses:

1. Nitrofurantoin 100 mg for UTI

Nitrofurantoin is primarily used to treat urinary tract infections (UTIs) caused by specific bacteria. UTIs can occur in various parts of the urinary system, including the bladder and kidneys. Nitrofurantoin is particularly effective against E. coli, one of the most common bacteria that cause UTIs.

2. Nitrofurantoin 100 mg During Pregnancy

Nitrofurantoin may be prescribed for UTIs during pregnancy, particularly in the second and third trimesters, when benefits outweigh risks. It is contraindicated at term (38–42 weeks) due to the risk of hemolytic anemia in newborns. Always consult a healthcare provider to ensure safe use during pregnancy.

3. Prevention of Recurrent UTIs

Nitrofurantoin is used prophylactically to prevent recurrent UTIs in individuals prone to frequent infections. A lower dose (50 mg or 100 mg at bedtime) may be prescribed for 3–12 months. This approach reduces the frequency of infections under medical supervision.

Available Forms of Nitrofurantoin:

Nitrofurantoin is available in several pharmaceutical forms, tailored to different patient needs and administration preferences. Below is a concise overview of the available forms of nitrofurantoin, including the 100 mg dosage:

1. Capsules:
   • Common Strength: 100 mg (standard dose for adults treating UTIs).
   • Other Strengths: 50 mg, 25 mg (often used for prophylaxis or pediatric dosing).
   • Description: Hard gelatin capsules, typically taken orally with food. The 100 mg capsule is widely prescribed for acute uncomplicated UTIs.
   • Examples: Macrodantin (macrocrystalline form, which reduces stomach upset).
2. Tablets:
   • Strengths: Similar to capsules (25 mg, 50 mg, 100 mg).
   • Description: Less common than capsules but available in some regions. Taken orally, often with food, and should not be crushed or chewed to avoid rapid drug release.
3. Oral Suspension:
   • Strength: Typically 25 mg/5 mL.
   • Description: A liquid form primarily used for children or patients who have difficulty swallowing capsules/tablets. Dosing is measured by weight for pediatric patients.
   • Administration: Shaken well before use and taken with food.
4. Dual-Release Capsules:
   • Strength: 100 mg (combination of macrocrystalline and monohydrate forms).
   • Description: Combines immediate release and sustained release forms for prolonged action (e.g., Macrobid). Typically taken twice daily for UTI treatment.
   • Note: Macrobid’s 100 mg formulation is distinct from Macrodantin due to its dual-release mechanism.

Dosage and Administration

Nitrofurantoin 100 mg is typically taken orally, with dosing tailored to the infection type and patient’s medical history. Proper administration enhances effectiveness and minimizes side effects. Below are the key details:

Nitrofurantoin 100 mg Dosage

Looking for the exact dosage by age or weight? Check our Nitrofurantoin Dosage Guide.

How to Take Nitrofurantoin Tablets?

Nitrofurantoin should be taken with food to improve absorption and reduce the risk of stomach upset. Swallow the tablet whole with a full glass of water. Do not crush, chew, or break the tablet, as this can release all the drugs at once, increasing the risk of side effects.

Side Effects of Nitrofurantoin 100 mg

Like all medications, Nitrofurantoin may cause side effects, though not everyone experiences them.

Common Side Effects

These side effects are usually mild and temporary. If they persist or worsen, consult your healthcare provider.

Serious Side Effects

While rare, some people may experience severe side effects. Seek immediate medical attention if you notice any of the following:

Allergic Reactions

Nitrofurantoin can cause allergic reactions in some individuals. Symptoms may include rash, itching, swelling (especially of the face, tongue, or throat), severe dizziness, or trouble breathing. If any of these symptoms occur, seek emergency medical help immediately.

Nitrofurantoin 100 mg and Alcohol

It is generally advisable to avoid alcohol while taking antibiotics, including Nitrofurantoin. Alcohol can increase the risk of side effects and may also reduce the effectiveness of the medication. Consult your healthcare provider for specific recommendations.

Nitrofurantoin 100 mg Interactions

Nitrofurantoin can interact with other medications, which may affect how it works or increase the risk of severe side effects. Inform your healthcare provider about all the drugs you are taking, including prescription, over-the-counter, and herbal products. Some everyday interactions include:

Precautions and Warnings

Before starting Nitrofurantoin 100 tablets, it‘s essential to take a few safety precautions to avoid unwanted side effects or complications:

Pre-existing Conditions

Before starting Nitrofurantoin, inform your healthcare provider if you have any pre-existing conditions such as:

Pregnancy and Breastfeeding

As mentioned earlier, Nitrofurantoin can be used during Pregnancy, particularly in the second and third trimesters. However, it should be used with caution and under medical supervision. Nitrofurantoin can pass into breast milk and may harm a nursing infant. Consult your healthcare provider before using this medication while breastfeeding.

Elderly Patients

Elderly patients may be more sensitive to the side effects of Nitrofurantoin, especially lung or liver problems.

Conclusion

Nitrofurantoin 100 mg is an effective antibiotic for treating urinary tract infections. However, it is essential to use it under the guidance of a healthcare provider to ensure its effectiveness and minimize the risk of side effects.

Always follow the prescribed dosage and be aware of potential interactions with other medications. If you experience any severe side effects or allergic reactions, seek medical attention immediately.

Frequently Asked Questions