Some medications can cause bone loss and if used for a long time can induce osteoporosis and weaken bone to that extent that they start breaking. These so called "bone unfriendly" medications are used for various conditions and often their use could not be avoided.
Corticosteroids are used for treatment of asthma, arthritis, systemic lupus, multiple sclerosis and numerous other conditions.
Phenobarbital and phenytoin are used to treat epilepsy.
Aromatase inhibitors (anastrazol, exenatide, letrozol) are used to treat breast cancer.
GnRH agonists (goserelin, buserelin, triptorelin) are used for treatment of endometriosis, prostate cancer and in IVF.
Proton pump inhibitors (omeprazole, lansoprazole, esomeprazole) are used for treatment of gastro-esophageal reflux, heartburn, peptic ulcer.
Heparin is used for prevention of blood clots.
Depo-Provera is used for long-term contraception.
Serotonin re-uptake inhibitors (fluoxetine, escitalopram) are used for treatment of depression.
Thyroxine used in patients with underactive thyroid if taken in excessive amount.
Patients who are at particularly high risk of experiencing negative effect of any of the above medications on their bone health are recently menopausal women (within four years of menopause), those who previously had low bone density or have already experienced fragility fracture, who have family history of osteoporosis, smokers, who have excessive alcohol intake and who are vitamin D deficient.
Bone loss appears to be continuous (while a patient is on therapy) with and increased risk of low trauma fracture reported on steroid treatment within relatively short period after initiation of high dose treatment. After discontinuation of treatment bone loss is reversible in many cases.
How can one prevent bone loss induced by any of the above mentioned medications? The lowest possible dose should be used for the shortest possible time. Adequate calcium intake (1 - 1.5 g daily) and optimizing vitamin D level (usually achieved by taking 1000 - 2000 IU of vitamin D daily) is essential. Weight-bearing and muscle-strengthening exercise should be encouraged whenever possible.
Any patient on long term therapy with known bone unfriendly medications should have DXA scan for assessment of bone density. If the T-score is below -2.0 treatment with bisphosphonate should be considered (particularly if other risk factors for fracture are present) in addition to basic preventive measures.