Clinical twisters: COPD leads to osteoporosis

February 19, 2007

A 75-year-old man, D.P., is seen regularly in your hospital clinic for severe chronic obstructive pulmonary disease (COPD) as a result of a 50-year pack-a-day habit (FEV<50% predicted). He quit smoking last year but still admits to being a heavy drinker. His current medications include fluticasone/ salmeterol 250/50 mcg (Advair, GlaxoSmithKline) one puff twice daily and albuterol inhaler when needed. He has had several COPD exacerbations within the past year, necessitating oral steroid therapy. He was just diagnosed with osteoporosis: recent X-rays show two vertebral fractures. His physician is contemplating osteoporosis therapy. What do you recommend?

D.P. developed osteoporosis secondary to corticosteroid therapy, heavy alcohol use, and smoking. Pharmacotherapy is indicated due to evidence of two previous spine fractures. Supplementation with calcium and vitamin D is warranted to prevent further bone loss. Bisphosphonate therapy will increase bone density, preventing future fractures. The drug of choice for this patient is alendronate/vitamin D3 (Fosamax Plus D, Merck) once weekly. Instruct D.P. to take it with a full glass of water first thing in the morning 30 minutes or more before eating or drinking, while remaining in an upright position for 30 minutes. He should supplement that with calcium 500 mg three times a day with meals. Monitor patient's bone mineral density with a DEXA scan at baseline and after a year of therapy.

Besides pharmacotherapy, focus attention on lifestyle and behavioral changes. Strongly encourage D.P. to decrease alcohol consumption. Excessive alcohol contributes to osteoporosis development. D.P.'s physician should evaluate him for medically supervised weight-bearing exercise to help increase bone density. Restrict caffeine intake; it interferes with calcium absorption. Encourage D.P. to continue to abstain from tobacco.

Regina M. Gonzalez, Pharm.D. candidate
Ivana Zovkic, Pharm.D. candidate
Midwestern University
Glendale, Ariz.

I would start by asking D.P.'s physician whether the osteoporosis is primary or secondary. This can be determined with pertinent blood work and X-rays to rule out cancers with bone metastasis, Cushing's disease, hypogonadism, hyperparathyroidism, thyrotoxicosis, nutritional disorders, and rheumatologic diseases. I would also check his medication history for medications that may worsen osteoporosis (barbiturates can accelerate vitamin D metabolism; phenytoin, phenobarbital, and carbamazepine can decrease calcium absorption). Other potential interferences include furosemide, methotrexate, levothyroxine, H2 blockers, and proton pump inhibitors.

Male patients at risk for osteoporosis are generally treated with the stored form of vitamin D (i.e., ergocalciferol 400-2000 IU/day and calcium 400-500 mg three times daily); divided calcium doses are needed because the human gut can absorb only 500 mg at one time. If D.P. had an underlying renal issue, I'd recommend the active form of vitamin D: calcitriol. Bisphosphonates, i.e., alendronate 10 mg daily or 70 mg once per week, risedronate (Actonel, Procter & Gamble) 5 mg daily or 35 mg once per week, or ibandronate (Boniva, Roche) once per month. Teriparatide (Forteo, Lilly), a once-a-day injectable, is another option, provided D.P. doesn't have Paget's disease, bone tumor risk, or elevated serum alkaline phosphate level and can afford the drug. Teriparatide stimulates osteoblast activity, increasing bone formation and bone density instead of inhibiting osteoclast activity as bisphosphonates do. It also lacks the severe GI side effects and special administration instructions of bisphosphonates.