Severe. These medicines may interact and cause very harmful effects and are usually not taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
St. John's wort may speed up how quickly your liver processes maraviroc.
What might happen:
The amount of maraviroc in your blood may decrease and it may not work as well against your HIV-infection.
What you should do about this interaction:
Let your healthcare professionals (e.g. doctor or pharmacist) know right away that you are taking these medicines together. Your doctor may want to check to see if your maraviroc has been working or if you have developed resistance to it. If you have not yet started taking St. John's wort, talk to your doctor before starting it.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.Reference:1.Selzentry (maraviroc) US prescribing information. Pfizer Inc. February, 2013.