Cefdinir with Iron Interaction Details
Brand Names Associated with Cefdinir
- Cefdinir
- Omnicef®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jan 02, 2024
Interaction Effect
Decreased cefdinir efficacy; formation of reddish stools
Interaction Summary
The coadministration of cefdinir and an iron supplement containing 60 mg of elemental iron as the ferrous sulfate salt or vitamins supplemented with 10 mg of elemental iron decreased the extent of cefdinir absorption by 80% and 31%, respectively. Therefore, cefdinir should be taken either two hours before or two hours after the administration of an iron supplement or a vitamin product containing iron. However, the coadministration of cefdinir oral suspension with iron-fortified infant formula has no significant effect on the pharmacokinetics of cefdinir. Coadministration of cefdinir with iron-containing infant formulas may result in the development of reddish color stools. A case was reported of a 9-month-old infant who developed red stools after the concomitant use of cefdinir and iron-supplemented infant formulas. The postulated mechanism of action is formation of a nonabsorbable complex between ferric ions and either cefdinir or one of it metabolites . Use caution with the concurrent administration of cefdinir and iron-containing infant formulas. Monitor patient for appearance of reddish color stools.
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
The administration of cefdinir and iron supplements or vitamins containing iron should be separated by at least two hours. When cefdinir is coadministered with iron-containing products, including infant formulas, reddish stools may occur as a result of the formation of a nonabsorbable complex between ferric ions and either cefdinir or one of it metabolites. The extent of the reddish discoloration of the stool is related to the dose of cefdinir administered. Concurrent administration of cefdinir with iron-containing infant formulas has not been shown to alter the absorption of cefdinir . Use caution with the concurrent administration of cefdinir and iron-containing infant formulas. Monitor patient for appearance of reddish color stools.
Mechanism Of Interaction
Decreased cefdinir absorption; formation of a nonabsorbable complex between ferric ions and either cefdinir or one of it metabolites
Literature Reports
A) A case was reported of a 9-month-old infant who developed red stools after the concomitant use of cefdinir and iron-supplemented infant formulas. The patient had failure to thrive and otitis media and was prescribed cefdinir 62.5 mg orally twice daily (15.4 mg/kg/day) after experiencing an allergic reaction to amoxicillin-clavulanate. On the fifth day of therapy, the patient was brought to a clinic with the appearance of red stools that the mother described as the "consistency of tomato paste". The infant showed no signs of associated gastrointestinal symptoms (vomiting, abdominal pain, or diarrhea) and was clinically stable. The otitis media appeared resolved and cefdinir was discontinued. Laboratory values were a hemoglobin of 10.7 g/dL and hematocrit of 33.1 mg/dL. Stool cultures were negative along with a celiac disease panel. After discontinuation of the cefdinir, the infant's stools returned to normal within 48 hours. A follow-up complete gastrointestinal exam was negative. The clinical diagnosis was most likely C. difficile infection associated with antibiotic therapy. The infant was on an infant formula with iron along with breast milk. Three weeks later, the patient returned with recurrence of otitis media and cefdinir was restarted at 62.5 mg orally twice daily. Red stools were once again noted within 48 hours after cefdinir initiation. No other gastrointestinal symptoms were present and results of the stool guaiac test were negative. Within 24 hours after cefdinir discontinuation, the red stools were resolved. The recurrence of red stools with the second administration of cefdinir, the consistent timing of the events, and the rapid resolution of red stools after discontinuation of cefdinir support cefdinir in combination with iron-supplemented formulas as causative of this reaction. This adverse event was highly probable according to the Naranjo adverse drug reaction probability scale .
Cefdinir Overview
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Cefdinir is used to treat certain infections caused by bacteria such as bronchitis (infection of the airway tubes leading to the lungs); pneumonia; and infections of the skin, ears, sinuses, throat, and tonsils.. Cefdinir is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.
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Antibiotics such as cefdinir will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.