Drug Interactions between simvastatin and Synthroid
This report displays the potential drug interactions for the following 2 drugs:
- Synthroid (levothyroxine)
Interactions between your drugs
Applies to: Synthroid (levothyroxine) and simvastatin
Information for this minor interaction is only available at a professional reading level.
Drug and food interactions
Applies to: simvastatin
Grapefruit juice can significantly increase the blood levels of simvastatin. This can increase the risk of side effects such as liver damage and a rare but serious condition called rhabdomyolysis that involves the breakdown of skeletal muscle tissue. In some cases, rhabdomyolysis can cause kidney damage and even death. You should avoid the consumption of grapefruit or grapefruit juice during treatment with simvastatin. Let your doctor know immediately if you have unexplained muscle pain, tenderness, or weakness during treatment, especially if these symptoms are accompanied by fever or dark colored urine. You should also seek immediate medical attention if you develop fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. 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.
Applies to: Synthroid (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.
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.
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.|
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.