Mirena Drug Interactions

By Kristi Monson, PharmD; Arthur Schoenstadt, MD |

When levonorgestrel (the hormone in Mirena) is taken in the form of a tablet, it can cause interactions with other medications. However, it is not known if this hormone interacts with certain medications when it is used in an intrauterine contraceptive (such as with Mirena). Drug interactions with levonorgestrel (in tablet form) may occur if it is taken with medications such as antibiotics, barbiturates, and certain seizure medications.

An Introduction to Mirena Drug Interactions

It is not known if Mirena^® can interact with other medications. Mirena is an intrauterine contraceptive (IUC) that contains levonorgestrel, a progesterone hormone often used in birth control pills. Although levonorgestrel (when taken by mouth, such as in the form of a birth control pill) interacts with many medications, it is not known if these interactions also apply to Mirena. Medications that may interact with levonorgestrel to decrease its effectiveness (and increase the risk of pregnancy) include:

Aminoglutethimide (Cytadren^®)
Antibiotics
Aprepitant (Emend^®)
Barbiturate medications, including, but not limited to:

Amobarbital (Amytal^®)
Butalbital (Fioricet^®, Fiorinal^®)
Pentobarbital (Nembutal^®)
Phenobarbital (Luminal^®)
Primidone (Mysoline^®)
Secobarbital (Seconal^®)

Bosentan (Tracleer^®)
Modafinil (Provigil^®)
Numerous seizure medications, such as:

Carbamazepine (Carbatrol^®, Epitol^®, Equetro™, Tegretol^®)
Felbamate (Felbatol^®)
Lamotrigine (Lamictal^®)
Oxcarbazepine (Trileptal^®)
Phenytoin (Dilantin^®, Phenytek^®)
Topiramate (Topamax^®)

St. John's wort (Hypericum perforatum).

Again, it is not clear if these interactions apply to Mirena or not. Typically, these interactions decrease the level of levonorgestrel in the blood. However, it is not known if a certain minimum blood level of levonorgestrel is necessary for Mirena to work, or if Mirena works right at the sight of insertion (at the uterus). Check with your healthcare provider for specific recommendations for your particular situation.