Menopause Home > Discussing Prempro Interactions With Your Doctor
St. John's Wort
St. John's wort (a commonly used herbal supplement) may cause your body to metabolize the hormones in Prempro too quickly, possibly leading to low levels of Prempro in the body. Although this can make Prempro less effective, it is not a dangerous drug interaction.
If you take Prempro with medications for an underactive thyroid (hypothyroidism), your healthcare provider may need to increase the dose of your thyroid medication. Your healthcare provider should monitor you and make any necessary dosing adjustments.
Various Antibiotics or Antifungals
Some antibiotic or antifungal medications may decrease the ability of your liver to metabolize Prempro, possibly leading to high levels of Prempro in the body. This may increase the risk of side effects. Check with your healthcare provider before combining Prempro with certain antibiotics or antifungals.