Bazedoxifene is a selective estrogen receptor modulator (SERM) developed in the early 2000s to prevent and treat postmenopausal osteoporosis. It works by mimicking estrogen in bone to maintain density while blocking estrogen effects in breast and uterine tissues, reducing cancer risk. Often available in combination with conjugated estrogens, bazedoxifene helps improve bone health and manage menopausal symptoms.
BRAND NAMES
Duavee (or Duavive): A combination of bazedoxifene and conjugated estrogens, used for hot flashes and osteoporosis prevention.
Conbriza/Viviant: Used for the treatment of postmenopausal osteoporosis.
MECHANISM OF ACTION
Bazedoxifene is a selective estrogen receptor modulator (SERM) that works by acting like estrogen in bones to maintain density and prevent fractures, while blocking estrogen effects in the breast and uterus to reduce cancer risk.
PHARMACOKINETICS
Absorption
Bazedoxifene is rapidly absorbed after oral administration, with peak blood levels typically reached within 8 to 12 hours. Its absorption is not significantly affected by food, and it undergoes extensive first-pass metabolism in the liver.
Distribution
Bazedoxifene is highly protein-bound, with approximately 98% of the drug bound to plasma proteins, mainly albumin.
Metabolism
Bazedoxifene is primarily metabolized in the liver through glucuronidation, forming inactive metabolites that are then excreted from the body.
Excretion
Bazedoxifene is mainly excreted through the feces, with only a small amount eliminated in the urine.
PHARMACODYNAMICS
Bazedoxifene is a selective estrogen receptor modulator (SERM) that strengthens bones by acting like estrogen in bone tissue while blocking estrogen effects in the breast and uterus, helping prevent osteoporosis and reducing cancer risk.
ADMINISTRATION
Bazedoxifene is administered orally, typically as a once-daily tablet. It can be taken with or without food, but should be taken at the same time each day to maintain consistent blood levels.
DOSAGE AND STRENGTH
Bazedoxifene is usually prescribed in a 10 mg oral tablet for the prevention and treatment of postmenopausal osteoporosis. When combined with conjugated estrogens, it is available in 20 mg/0.45 mg or 20 mg/0.625 mg tablet strengths.
FOOD INTERACTIONS
Bazedoxifene can be taken with or without food, and its absorption is not significantly affected by meals. However, high-fat meals may slightly delay absorption, but this does not affect overall effectiveness.
DRUG INTERACTIONS
Strong CYP3A inducers (e.g., rifampin, phenytoin) – may reduce bazedoxifene levels and effectiveness.
Cholestyramine – can reduce absorption if taken at the same time.
Other estrogen-containing therapies – co-administration may alter effects or increase side effects.
CONTRAINDICATIONS
Known hypersensitivity to bazedoxifene or any component of the formulation.
Active or past venous thromboembolism (e.g., deep vein thrombosis or pulmonary embolism).
Severe liver impairment.
Pregnancy or breastfeeding.
Unexplained vaginal bleeding until the cause is determined.
SIDE EFFECTS
Common side effects of bazedoxifene include:
Hot flashes
Muscle or joint pain
Upset stomach or nausea
Diarrhea or constipation
Leg cramps
TOXICITY
Bazedoxifene is a selective estrogen receptor modulator (SERM), mainly used to prevent osteoporosis in postmenopausal women.
