Drug Interactions between aliskiren and Synthroid

The timing of meals relative to your oral levothyroxine dose can affect the 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 and/or delayed by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, calcium fortified juices and grapefruit or grapefruit juice. 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.

Food can affect the absorption of aliskiren from the intestine. Therefore, you should take aliskiren at the same time each day exactly as prescribed by your doctor. You may take aliskiren with or without food, but take it the same way every time. This will help keep blood levels and effects of the medication steady. You should avoid drinking orange, apple, or grapefruit juice as much as possible during treatment with aliskiren. Studies have shown that drinking these juices regularly or within a short period before or after a dose of aliskiren can interfere with the absorption of the medication.

Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine. You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. 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.