There are a number of categories of drugs that can have a negative effect on bone:
Thyroid hormone therapy: Sufficient levels of thyroid hormones are necessary for normal
bone development; excessive amounts, however, can cause bone loss over time.
Anticonvulsants: Interfere with vitamin D metabolism, thereby lowering the availability
of calcium for bone mineralization. The two widely used anti-epileptic drugs phenytoin (Dilantin®) and
carbamazepine (Tegretol®) are recognized to have direct effects on bone cells.
Aluminum-containing antacids: Interfere with the intestinal absorption of calcium.
Antineoplastics (cancer treatments): Used to treat a variety of cancers, immune disorders
and resistant arthritic conditions. Cancer treatment-induced bone loss (CTIBL) is most common in breast
(including aromatase inhibitors) or prostate cancer patients undergoing therapies resulting in low levels of
sex hormones.
Immunosuppressives: Used in organ transplants and for the treatment of some diseases of
the immune system.
Gonadotropin-releasing hormone (GnRH) analogues: Used in the long-term treatment of
endometriosis and uterine fibroids. GnRH therapy decreases production of the hormone estrogen to the levels
women have after menopause. GnRH analogues are used in the treatment of breast cancer in women to suppress
estrogen levels, and in prostate cancer in men to suppress testosterone levels.
Anticoagulants: Used to prevent blood clotting. Vitamin K is one of several vitamins that
play a role in bone metabolism. Since some oral anticoagulants interfere with vitamin K, their long-term use
may increase the risk of osteoporosis, particularly of the spine and ribs.
Conception control agents: Reports suggest that women who use Depo-Provera® may lose
significant bone mineral density, possibly because of the low estrogen that it induces.
Thiazolidinediones (diabetes medication): A study found a higher risk of fractures among
women who take the drug rosiglitazone (Avandia®), possibly because the drug increases the activity of the
cells that absorb bone in the bone remodelling process. Also, clinical trials have shown that female patients
treated with pioglitazone (ACTOS®) for type 2 diabetes mellitus were at an increased risk of fracture,
particularly of the forearm, hand and wrist, and foot, ankle, fibula and tibia. No increased risk of fracture
was identified in men.
Drugs used for heartburn and ulcers: Proton pump inhibitors that reduce stomach acid
production have been associated with an increased fracture risk, perhaps because calcium absorption from food
is less efficient in the absence of stomach acid.
Anti-depressants: Daily use of SSRIs (selective serotonin reuptake inhibitors), a popular
anti-depressant, may lead to increased risk for fragility fracture in older adults. Daily use of SSRIs is
associated with a reduction in bone density in the hip and spine and with an increased risk of falling.
Examples of drugs in this class include Prozac®, Paxil® and Zoloft®.
Not all drugs in each category affect bone health, so be sure to ask your physician to consider one that
is less harmful to bone.
