National Stroke Foundation


The following drug information is obtained from various newswires, published medical journal articles, and medical conference presentations.

Approval Status:

Approved April 2002

Specific Treatments:

Postmenopausal osteoporosis, Vasomotor menopausal symptoms

General Information

Alora is an estrogen replacement therapy system approved for the prevention of postmenopausal osteoporosis. In 1996, Alora was approved for the treatment of moderate-to-severe vasomotor menopausal symptoms, specifically hot flashes. The Alora patch is thin, flexible and virtually transparent when worn on the skin. The patch can be placed on the abdomen, hip or buttock and is available in four dosage strengths. It is applied twice weekly and is worn continuously for three or four days.

Osteoporosis is a thinning of the bones that makes them weaken and more prone to breakage. Women who undergo menopause at an early age, are thin, smoke or have a family history of osteoporosis are more likely to develop this debilitating disease.

Clinical Results

Approval of Alora is supported by a double-blind, placebo-controlled trial involving 268 postmenopausal women who experienced an average of at least 60 moderate-to-severe hot flashes during the screening period. At weeks four and 12, Alora was seen to be statistically better than placebo at relieving the frequency and severity of vasomotor symptoms.

Alora was also tested in clinical trials in 355 hysterectomized, non-osteoporotic women to measure the drug's effect on bone mineral density (BMD). Alora was shown to increase lumbar spine BMD statistically better than placebo.

Side Effects

Adverse events associated with the use of Alora may include (but are not limited to) the following:

  • Headache
  • Nausea
  • Vomiting
  • Breast tenderness or enlargement
  • Retention of excess fluid
  • Vaginal spotting or bleeding

Mechanism of Action

Alora (estradiol) is a transdermal system designed to deliver estradiol, a human estrogen. Estrogens bind to nuclear receptors in estrogen-responsive tissues and modulate the pituitary secretion of the gonadotropins luteinizing hormone and follicle stimulating hormone through a negative feedback mechanism. Estrogen replacement therapy acts to reduce the elevated levels of these hormones seen in postmenopausal women.

The skin metabolizes estradiol only to a small extent compared to orally adminstered estradiol, which is rapidly metabolized into estrone, leading to higher circulating levels of estrone than estradiol. Transdermal administration then, produces therapeutic estradiol levels with lower levels of estrone and requires smaller doses.

Additional Information

For additional information on Alora, please visit Alora.