Glyburide (DiaBeta, Glynase, Micronase)
WelChol may decrease the absorption of
glyburide into the body, perhaps making it less effective. Glyburide should be taken at least four hours before a dose of WelChol to avoid this interaction. If you take WelChol twice a day and have trouble timing the doses of glyburide and WelChol, ask your healthcare provider about taking WelChol just once a day instead of twice a day, as this can help make avoiding this interaction easier.
Levothyroxine (Levoxyl, Levothroid, Synthroid, Unithroid)
WelChol may decrease the absorption of
levothyroxine into the body, perhaps making it less effective. Levothyroxine should be taken at least four hours before a dose of WelChol to avoid this interaction.
Oral Contraceptives
WelChol has been shown to decrease the absorption of certain
birth control pills (those that contain ethinyl estradiol in combination with norethindrone), perhaps increasing the risk of pregnancy. WelChol has not been studied in combination with other birth control pills, and it is likely that WelChol will interact similarly with other birth control pills as well. Birth control pills should be taken at least four hours before a dose of WelChol.
Phenytoin (Dilantin, Phenytek)
There have been reports of WelChol interacting with
phenytoin, perhaps decreasing its absorption and making it less effective. To avoid this interaction, take phenytoin at least four hours before a dose of WelChol.
Warfarin (Coumadin, Jantoven)
Although there have been reports that WelChol may interact with warfarin, studies have not demonstrated any interaction between these two medications. Interactions may occur due to a decreased absorption of vitamin K, since vitamin K can affect warfarin. Check with your healthcare provider in this situation, as you may need to be monitored more closely.