Actos Drug Interactions
Certain medications can affect the way Actos (pioglitazone) works in the body. These medications can either potentiate or reduce the effects of Actos. Therefore, patients taking Actos should be aware of the different drugs that can possibly interact with this medication.
Significant Drug Interactions
Some of the drugs that are known to interact with Actos include:
CYP2C8 inhibitors – Actos is processed in the body through the CYP3C8 metabolic pathway. However, certain medications can significantly reduce the action of CYP2C8 enzyme. Combining Actos with a strong CYP2C8 can cause reduced metabolism and excretion of pioglitazone in the body. This can lead to increased blood levels of Actos, possibly increasing the risk of side effects. Therefore, patients taking strong CYP2C8 inhibitors are usually given lower dose of Actos (15 mg per day).
- Gemfibrozil (Lopid)
- Atazanavir (Reyataz)
- Ritonavir (Norvir)
- Ketoconazole (Nizoral)
CYP2C8 inducers – Certain medications, known as CYP2C8 inducers, may potentiate the action of the enzyme CYP2C8. Combining Actos with this medication can significantly increase the metabolism and excretion of the medication from the body, possibly making the drug less effective. Patients taking Actos together with strong CYP2C8 inducers may require adjustments in diabetes treatment. However, the daily dose of Actos should not exceed 45 mg.
- Rifampin (Rifadin, Rimactane)
- Certain Seizure Medications
- Carbamazepine (Tegretol)
- Fosphenytoin (Cerebyx)
- Phenobarbital (Luminal)
- Phenytoin (Dilantin)
- Primidone (Mysoline)
Certain antilipemics – Clinical studies show that taking atorvastatin with Actos can decrease the blood levels of both drugs, probably making both medications less effective. Patients taking Actos with antilipemics, particularly atorvastatin, may require dose adjustments.
- Atorvastatin (Lipitor)
Certain antianxiety drugs - Clinical studies show that taking midazolam with Actos can decrease the blood levels of both drugs, probably making both medications less effective. Patients taking Actos together with antianxiety medications, particularly midazolam, may require dose adjustments.
- Midazolam (Versed)
Nifedipine - Clinical studies show that taking nifedipine with Actos can decrease the blood levels of both drugs, probably making both medications less effective. Patients taking Actos together with nifedipine may require dose adjustments.
- Nifedipine (Adalat, Procardia)
Oral Birth Control Pills – Actos can potentially reduce the level of oral contraceptive in the body. It is not known whether this will decrease the effectiveness of the birth control pills. Your healthcare provider may recommend use of other birth control measures or possibly dose adjustments.
If you are taking any of these medications, you should inform your healthcare provider. Take note however that this medication guide may not contain all medications that can possibly interact with Actos. Therefore, be sure to inform your healthcare provider of all drugs you take, prescription and nonprescription medications including vitamins, natural supplements and other health products.