Written By: Abier Hamami. RPH. CPHQWhat are Bisphosphonates?
Bisphosphonates are a family of drugs used to prevent and treat Osteoporosis, and other bone diseases as Paget¢s disease. Among them are Alendronate (Fosamax ®), Etidronate (Didrocal ®) and Risedronate (Actonel ®). Also they are used in bone metastasis (with or without hypercalcemia) and in multiple myeloma as Pamidronate (Aredia ®) or Clodronate (Bonefos ®).

How do they work?
Bisphosphonates bind to the surfaces of the bones and slow down the Osteoclasts (bone-eroding cells). This allows the Osteoblasts (bone-building cells) to work more effectively. Thus increase bone density and prevent fractures.

Who can take them?
Bisphosphonates are used for many indications, among them prevention and treatment of Osteoporosis in: postmenopausal women, and men and women of any age who are using steroid medications.

What are the instructions for their use?
They should be taken early in the morning 1/2 hour before eating or 2 hours after with a full glass of water( avoid drinking juice, mineral water, and coffee). Taking the pill sitting or standing minimizes the chances of the pill being lodged in the esophagus. Patients should also remain upright and avoid lying down for at least 30 minutes after taking the pill to avoid reflux of the pill into the esophagus.

What is their frequency of use?

Bisphosphonates are available in 2 forms; oral and injectable, and could be used daily, weekly, monthly, or every 3 months according to their strength, form, and clinical condition.

What are their side effects?
The most common side effects are nausea, abdominal pain and loose bowel movements. There is a small risk of ulcers in the esophagus especially if taken incorrectly. They can also cause bone, joint &/or muscle pain and sometimes severe enough to stop taking the drug.

In extremely rare cases, some have been linked to a breakdown of the jaw bone following dental work (Osteonecrosis of jaw bone).

What are their contra indications?

They are contraindicated in:

Women who are pregnant or planning pregnancyRenal insufficiency Low serum calciumOsteomalacia/Rickets ( Vitamin D deficiency)Patients with serious esophageal diseasePatients at bedrest who can't stay upright for an hour

They should be used with caution in:

Patients with abnormal white blood cells Patients with high parathyroid hormone PTHChildren (no long-term safety data)

What about taking other medications?

Calcium, iron supplements, vitamins with minerals, or antacids containing calcium, magnesium, or aluminum can reduce the absorption of Bisphosphonates, thereby resulting in loss of effectiveness. Therefore, it is very important that your doctor knows if you are taking any other medicine. This includes prescription and non-prescription medicines as well as vitamins and herbal supplements.

August 16 -2005

References:

http://courses.washington.edu/bonephys/opbis.html
http://www.aafp.org/afp/20000501/2731.html
http://www.osteoporosis.ca/english/About%20Osteoporosis/Drug%20Treatments/Bisphosphonates/default.asp?s=1
http://www.webmd.com/hw/osteoporosis/hw130875.asp
http://www.medscape.com/viewarticle/448205