Minocycline with Iron Interaction Details
Brand Names Associated with Minocycline
- Dynacin®
- Minocin®
- Minocycline
- Myrac®
- Solodyn®
- Ximino®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jan 04, 2024
Interaction Effect
Decreased tetracycline and iron effectiveness
Interaction Summary
The concurrent administration of ferrous salts (40 mg or more of iron) and tetracycline derivatives can lead to decreased levels of the tetracycline (50% to 90%) and decreased absorption of the ferrous salt (up to 50%).
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
If both medications must be used concurrently, iron salts should be given not less than 3 hours before or 2 hours after the minocycline dose.
Mechanism Of Interaction
Decreased tetracycline and iron absorption
Literature Reports
A) Impaired gastrointestinal absorption of tetracycline by the concomitant administration of oral ferrous sulfate is well known. Ferrous sulfate has also been shown to interfere with the absorption of the tetracycline analogues, oxytetracycline, methacycline, and doxycycline . The absorption of other analogues may be affected as well.
B) Ferrous sulfate has been shown to significantly decrease the absorption of oxytetracycline . The administration of ferrous sulfate 250 mg with oral oxytetracycline 500 mg as a single dose significantly decreased oxytetracycline serum concentrations. The serum levels with oxytetracycline alone were 2.3 mcg/mL compared to a maximum of 1 microgram/mL with the combination.
C) Since this interaction may lead to serum levels of the antibiotic which are below the minimum inhibitory concentration, the effect of the time interval between tetracycline and iron administration was investigated in 38 healthy medical students . It was demonstrated that when tetracycline 500 mg, is ingested at 0.5, 1 or 2 hours after ferrous sulfate 600 mg, significant reductions in plasma levels of the antibiotic occur. Similar results were obtained when the tetracycline was taken 1 hour before the iron. However, the results of this investigation did indicate that when iron was administered 3 hours before or 2 hours after tetracycline, satisfactory antibiotic serum levels were achieved.
D) The exact mechanism by which iron impairs tetracycline absorption is not known. However, since tetracycline binds with various polyvalent metallic cations , two mechanisms have been proposed: 1) inhibited absorption may result from the formation of tetracycline-iron chelates or 2) when ferrous ion is present, the tetracyclines may bind to intestinal protein residues . Additionally, iron may bind doxycycline when it passes through the intestine via its enterohepatic circulation, therefore even parenteral doxycycline would be a problem with iron .
E) A reduction in half-life of IV doxycycline from 16.6 h to 11 h when given simultaneously with oral iron has been demonstrated . The same study indicated that 200 mg oral doxycycline given 3, 7, and 11 h prior to 80 mg of elemental iron (ferrous sulfate) still resulted in a 20% to 45% reduction in serum doxycycline. Therefore, a three hour interval between dosing may not be adequate when doxycycline and iron are prescribed simultaneously .
Minocycline Overview
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Minocycline is used to treat infections caused by bacteria including pneumonia and other respiratory tract infections; certain infections of the skin, eye, lymphatic, intestinal, genital, and urinary systems; and certain other infections that are spread by ticks, lice, mites, and infected animals. It is also used along with other medications to treat acne. Minocycline is also used to treat plague and tuleramia (serious infections that may be spread on purpose as part of a bioterror attack). It can also be used in patients who cannot be treated with penicillin to treat certain types of food poisoning, and anthrax (a serious infection that may be spread on purpose as part of a bioterror attack). It can also be used to eliminate bacteria from your nose and throat that may cause meningitis (swelling of tissues around the brain) in others, even though you may not have an infection. Minocycline extended-release tablet (Solodyn) is only used to treat acne. Minocycline is in a class of medications called tetracycline antibiotics. It works to treat infections by preventing the growth and spread of bacteria. It works to treat acne by killing the bacteria that infects pores and decreasing a certain natural oily substance that causes acne.
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Antibiotics such as minocycline 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.