Drug Interactions between ferrous sulfate and levothyroxine
This report displays the potential drug interactions for the following 2 drugs:
- ferrous sulfate
- levothyroxine
Interactions between your drugs
levothyroxine ferrous sulfate
Applies to: levothyroxine and ferrous sulfate
Levothyroxine and ferrous sulfate should not be taken orally at the same time. Products that contain iron may interfere with the absorption of levothyroxine and reduce its effectiveness. You should separate the dosing of these medications by at least 2 to 4 hours if possible. Contact your doctor if your condition changes or you experience symptoms of hypothyroidism such as dry skin, weight gain, cold intolerance, weakness, muscle cramps or stiffness, slow pulse, or constipation. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Drug and food interactions
levothyroxine food
Applies to: levothyroxine
The timing of meals relative to your levothyroxine dose can affect absorption of the medication. Therefore, levothyroxine should be taken on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in blood levels, which may alter its effects. In addition, absorption of levothyroxine may be decreased by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, and calcium fortified juices. These foods should be avoided within several hours of dosing if possible. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
When levothyroxine is given during continuous enteral nutrition (tube feedings) for more than 7 days, the tube feeding should be interrupted for at least one hour before and one hour after the dose of levothyroxine. You may need more frequent blood tests to monitor levothyroxine levels.
ferrous sulfate food
Applies to: ferrous sulfate
Food may reduce the absorption and blood levels of ferrous sulfate. In addition, some oral medications can also interfere with ferrous sulfate absorption into the bloodstream, which may make the medication less effective in treating your condition. Likewise, ferrous sulfate may interfere with the absorption of other orally administered medications. You should take ferrous sulfate on an empty stomach at least one hour before or two hours after a meal. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring to safely use both medications. Talk to your doctor or pharmacist if you have questions about how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Report options
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.