What is "dual release" nitrofurantoin?
Medically reviewed by Drugs.com. Last updated on May 12, 2025.
In the nitrofurantoin dosage information, it refers to "regular release" and "dual release" formulations of nitrofurantoin. What is the difference?
Dual release nitrofurantoin refers to the nitrofurantoin monohydrate/macrocrystalline nitrofurantoin capsule formulation, which is available under the brand name Macrobid and its generics.
Nitrofurantoin is an antibacterial agent specific for the treatment of urinary tract infections.
Nitrofurantoin capsules are available in two formulations:
- Macrodantin and its generics which contain macrocrystalline nitrofurantoin.
- Macrobid and its generics which contain nitrofurantoin monohydrate and macrocrystalline nitrofurantoin.
Macrocrystalline nitrofurantoin (Macrodantin) is sometimes referred to as regular release nitrofurantoin.
Nitrofurantoin monohydrate/macrocrystalline nitrofurantoin (Macrobid) is sometimes referred to as dual release nitrofurantoin.
The dual release nitrofurantoin formulation contains both the regular release macrocrystalline nitrofurantoin, and nitrofurantoin monohydrate. The nitrofurantoin monohydrate powder blend in the capsule forms a gel matrix upon exposure to gastric and intestinal fluids, allowing the nitrofurantoin to be released slowly over time and a providing longer dosing interval of twice a day, compared to four times a day with the regular release formulation .
In the treatment of urinary tract infections (cystitis):
- regular release nitrofurantoin is dosed four times a day
- dual release nitrofurantoin is dosed twice a day.
For the prevention of urinary tract infections
- regular release nitrofurantoin is dosed once a day.
For more information, see Nitrofurantoin Dosage.
Related questions
- What antibiotics are used to treat UTI?
- Is meloxicam a sulfa drug?
- Does Macrobid make birth control pills less effective?
Read next
How long does Cipro take to work?
Although ciprofloxacin starts working within hours of taking it, you may not notice an improvement in your symptoms for 2 to 3 days. For some infections, such as osteomyelitis (a bone infection), it may take up to a week before you show any improvement. Continue reading
Are UTIs contagious?
UTIs are not contagious nor sexually transmitted – that is you cannot catch them from another person – but some women do get them frequently and they can occur after sexual activity, when bacteria in the vaginal area get pushed near or into the urethra. In most cases, the sexual partners of a person with a UTI will not need treatment. Continue reading
Is amoxicillin safe for dogs?
Amoxicillin is a safe oral, broad-spectrum antibiotic prescribed by veterinarians for bacterial infections in dogs. Amoxicillin is well-tolerated by most dogs, but common side effects may occur, like diarrhea, nausea, stomach pain, skin rash or allergy. Contact your veterinarian right away if you have concerns about amoxicillin side effects in your dog. Continue reading
See also:
Aimovig
Learn about Aimovig (erenumab-aooe) a once-monthly, injectable medication that can be ...
Botox
Botox is used for cosmetic purposes and to treat overactive bladder symptoms, urinary incontinence ...
Ozempic
Learn about Ozempic (semaglutide) for type 2 diabetes treatment, weight management, cardiovascular ...
Nurtec ODT
Nurtec ODT (rimegepant) is used to treat acute migraines and prevent episodic migraines, by ...
Emgality
Emgality (galcanezumab-gnlm) is a CGRP antagonist for the preventive treatment of migraine and for ...
Inderal
Inderal (propranolol) is used to treat angina, high blood pressure and heart rhythm disorders ...
Ajovy
Ajovy (fremanezumab-vfrm) is a preventive migraine treatment. Includes Ajovy side effects ...
Vyepti
Vyepti (eptinezumab-jjmr) is used for the preventive treatment of migraine. Includes Vyepti ...
Botox Cosmetic
Botox Cosmetic is a prescription treatment for fine lines and wrinkles. It temporarily improves the ...
Fremanezumab
Fremanezumab is used for chronic migraine, headache, migraine, migraine prevention
Related medical questions
- Does a UTI always need to be treated with an antibiotic?
- What happens if antibiotics don’t work for UTI?
- Does Flagyl treat UTI infections?
- UTI vs Bladder vs Yeast Infections - What's the difference?
- Does Cranberry interact with any drugs?
- What dose of co-trimoxazole is used in a patient with a UTI?
- Does Bactrim cause headaches?
- How to treat a UTI at home?
- Can clarithromycin be used to treat UTI's?
- Does cranberry juice help prevent a UTI?
- Do I have a Urinary Tract Infection?
- How do you get a bladder infection?
- How do you know if you have a bladder infection?
- Hot Flashes, Mood Swings... wait... could this be Menopause?
- What do I need to know about Medications/Vaccinations before I Travel?
- What type of drug is Zemdri?
- What drugs are contained in Vabomere?
- Smart use of Antibiotics
Drug information
Related support groups
- Nitrofurantoin (55 questions, 65 members)
- Macrobid (37 questions, 55 members)
- Macrodantin (5 questions, 14 members)
- Urinary Tract Infection (204 questions, 602 members)
- Bladder Infection (62 questions, 159 members)