Medically reviewed by Alan Lucks | MD, Alan Lucks MDPC Private Practice - New York on December 8th, 2025.
Macrobid (nitrofurantoin) is commonly prescribed for urinary tract infections (UTIs) with specific dosage guidelines depending on age and condition.
Typical adult dosage is 100 mg twice daily for 5 to 7 days; pediatric doses vary based on weight and age.
It is important to take Macrobid with food to improve absorption and reduce stomach upset.
Missed doses should be taken as soon as remembered, but never doubled up to catch up.
Adjustments may be necessary for patients with kidney impairment or other medical conditions.
Doctronic.ai offers personalized dosage advice and 24/7 telehealth visits with licensed doctors for any questions about Macrobid or other medications.
Macrobid, known generically as nitrofurantoin, is a trusted antibiotic frequently used to treat uncomplicated urinary tract infections. Its effectiveness hinges not only on taking the medication but on following the correct dosage and timing. Taking Macrobid properly ensures the infection clears up quickly and reduces the risk of antibiotic resistance.
Whether you are an adult or a parent managing your child’s treatment, understanding the right dose and schedule is crucial. This guide breaks down the typical dosages, how to take Macrobid safely, and what to do if you miss a dose. Plus, it highlights how Doctronic.ai can help you get personalized advice anytime you need it.
Form |
Strength |
Typical Adult Dose |
Typical Children’s Dose |
Frequency |
Route |
Maximum Daily Dose |
|---|---|---|---|---|---|---|
Capsule |
100 mg |
100 mg twice daily |
5-7 mg/kg/day divided into 2 doses |
Twice Daily |
Oral |
200 mg/day |
The most common use of Macrobid is for treating uncomplicated UTIs in adults. The standard dose is 100 mg taken twice daily for 5 to 7 days. This regimen is designed to effectively clear the infection while minimizing side effects.
For children, the dose is calculated based on body weight, typically 5 to 7 mg per kilogram per day, divided into two doses. Treatment duration is similar, usually 5 to 7 days, but always follow your healthcare provider’s instructions.
In some cases, Macrobid is prescribed as a preventive measure for recurrent urinary tract infections. The dosage for prophylaxis is usually lower, often 50 to 100 mg once daily at bedtime. This helps maintain antibiotic levels in the urinary tract to prevent infection recurrence.
Adults typically take 100 mg of Macrobid twice daily, preferably with food to enhance absorption and reduce gastrointestinal discomfort. The usual course lasts 5 to 7 days for active infections. It’s important not to stop the medication early, even if symptoms improve, to ensure the infection is fully eradicated.
For pediatric patients, dosing is weight-based. The recommended dose ranges from 5 to 7 mg per kilogram of body weight per day, divided into two doses. This precise dosing ensures safety and effectiveness. Always consult a healthcare provider before giving Macrobid to children, as individual needs may vary.
If you miss a dose of Macrobid, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed one and resume your regular schedule. Do not double the dose to catch up, as this can increase the risk of side effects without improving treatment outcomes.
Macrobid is primarily eliminated by the kidneys, so patients with reduced kidney function require special attention. It is generally not recommended for those with severe renal impairment (creatinine clearance under 60 mL/min) because the drug may not reach effective levels in the urine and can accumulate in the body, increasing the risk of toxicity.
While Macrobid is not extensively metabolized by the liver, patients with liver conditions should still inform their healthcare provider. Adjustments are rarely needed, but monitoring may be advised.
Taking more than the prescribed dose of Macrobid can lead to serious side effects such as nausea, vomiting, and in rare cases, lung or liver damage. If an overdose is suspected, seek emergency medical attention immediately.
Macrobid is contraindicated in patients with significant kidney disease and in late pregnancy due to the risk of hemolytic anemia in newborns. Always disclose your full medical history to your healthcare provider before starting Macrobid.
Take Macrobid with food or milk to reduce stomach upset and improve absorption.
Complete the full course of treatment even if symptoms improve early.
Do not crush or chew capsules; swallow them whole.
Inform your doctor about any other medications you are taking to avoid interactions.
Report any unusual side effects such as persistent cough, chest pain, or yellowing of the skin immediately.
When it comes to antibiotic dosing, one size does not fit all. That’s where Doctronic.ai comes in. As the #1 AI Doctor, Doctronic provides personalized, up-to-date medical advice tailored to your unique health profile.
Doctronic’s AI synthesizes the latest peer-reviewed medical research to answer your dosage questions quickly and accurately. Whether you want to confirm your Macrobid dose or need guidance on side effects, Doctronic remembers your history and offers care that feels personal. Plus, if you want to speak with a real doctor, Doctronic offers affordable telehealth video visits 24/7 across all 50 states.
Visit Doctronic.ai today to get fast, smart, and personal answers about Macrobid and other medications.
Macrobid remains a reliable choice for treating and preventing urinary tract infections when taken correctly. Understanding the right dose, timing, and precautions can make all the difference in your recovery. If you ever feel uncertain about your dosage or experience side effects, don’t hesitate to seek expert advice.
With Doctronic.ai, you have access to cutting-edge AI-powered medical guidance and real doctors anytime you need them. This combination of technology and human care ensures you get the best possible outcomes from your treatment.
It’s best to take Macrobid with food or milk to improve absorption and reduce stomach upset.
Most people start to feel better within a few days of starting treatment, but it’s important to finish the full course.
Macrobid is generally avoided in late pregnancy due to risks to the newborn. Always consult your doctor before use.
If you notice severe side effects like difficulty breathing, persistent cough, or yellowing skin, contact a healthcare provider immediately.
Macrobid is specifically effective for urinary tract infections and is not typically used for other types of infections.
Doctronic.ai offers AI-powered personalized medical advice and 24/7 telehealth visits with licensed doctors to help answer your questions.
Key TakeawaysMacrobid (nitrofurantoin) is commonly prescribed for urinary tract infections (UTIs) with specific dosage guidelines depending on age and condition.Typical adult [...]
Read More
