Can Macrobid Capsules Be Opened?
In our latest question and answer, the pharmacist discusses why Macrobid capsules should not be opened.
I was diagnosed with a UTI and prescribed Macrobid (nitrofurantoin). Can I open the capsules?
Jul 28, 2022- Macrobid capsules should be swallowed whole because the powder can irritate your mouth and throat and may dissolve too quickly, causing more side effects.
- Opening the capsule can disrupt how the medication releases in your body and create a choking hazard.
- If you cannot swallow capsules, ask your doctor about the liquid suspension form instead, which is specially formulated to avoid irritation.
Answer
Although Macrobid (nitrofurantoin monohydrate; nitrofurantoin macrocrystals) capsules contain a dry powder and are not technically an extended-release product (more on this below), they are not recommended to be opened. They should be swallowed whole. This is for a few reasons.
Why Macrobid Capsules Should Not Be Opened
First and foremost, nitrofurantoin has been reported to cause esophageal irritation when applied directly to mucous membranes in the mouth and throat. The capsule protects the powder from coming into contact with these areas and improves tolerability.
Additionally, Macrobid capsules actually contain two forms of nitrofurantoin, "monohydrate" and "macrocrystals".The macrocrystalline form is more slowly absorbed due to a slower rate of dissolution. This form can produce fewer adverse gastrointestinal effects. However, if it comes into contact with saliva/gastric juices early, it may dissolve faster, causing more side effects.
Lastly, Macrobid, in a technical sense, is not an extended-release product as the capsule itself does not have extended-release properties.
However, when exposed to gastric and intestinal fluids, the nitrofurantoin monohydrate component of Macrobid forms a gel matrix and releases nitrofurantoin over time. This is why it is able to be dosed only twice a day, when compared to other nitrofurantoin products (e.g. Macrodantin), which need to be dosed four times a day.
Opening Macrobid capsules and taking the powder can cause the gel matrix to form too early, creating a choking hazard and potentially altering the extended-release properties.
Final Words
If you are unable to take the capsule form, it is available in a liquid suspension dosage form with a strength of 25mg/mL. Ask your doctor if they are able to prescribe that for you instead. It is specifically formulated not to cause the mouth/throat irritation the powder form can cause.
References & sources
- Pharmaceutical Issues when Crushing, Opening or Splitting Oral Dosage Forms — Royal Pharmaceutical Society
- Macrobid Prescribing Information — AccessFDA
Glossary — Terms in This Answer
- Nitrofurantoin
- An antibiotic medication used to treat urinary tract infections.
- Esophageal irritation
- Inflammation or discomfort in the tube that carries food from your mouth to your stomach.
- Mucous membranes
- Moist tissue linings inside your mouth, throat, and other body passages.
- Macrocrystals
- Large crystal-form particles of medication that dissolve slowly in the body.
- Monohydrate
- A form of medication that contains water molecules bonded to the drug.
- Dissolution
- The process of a solid substance breaking down and mixing into a liquid.
- Gel matrix
- A gel-like framework that forms in the stomach and releases medication slowly over time.
- Suspension
- A liquid medication form where fine particles are evenly distributed throughout the liquid.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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