HOUSTON, TEXAS. It is well known that both the osteoporosis drug alendronate sodium (Fosamax) and naproxen, a popular non-steroidal anti-inflammatory drug (NSAID), can cause damage to the stomach lining including the actual development of stomach ulcers. Researchers at the Baylor College of Medicine now report that a combination of alendronate and naproxen is considerably more dangerous than either drug on its own.
Their clinical trial involved 26 healthy volunteers (18 women and 8 men) between the ages of 30 and 50 years. The study participants were randomized to receive either 10 mg of alendronate once a day, 500 mg of naproxen twice a day or a combination of the two for a 14-day period. The presence of stomach lining damage was measured using videoendoscopy at the beginning and end of the test periods. The first test period was followed by a one-week wash-out period after which the participants were assigned to another regimen and so on until all the participants had tried all three regimens.
The researchers found that 10 mg/day of alendronate produced ulcers in 8 per
cent of the participants, 500 mg of naproxen twice a day produced ulcers in 12
per cent, and 10 mg/day of alendronate plus 500 mg of naproxen twice a day
produced ulcers in 38 per cent of the volunteers and significant side effects in
69 per cent. It is clear that alendronate and naproxen act synergistically in
inducing stomach ulcers. The researchers conclude "it would appear prudent not
to prescribe anti-inflammatory doses of traditional NSAIDs to patients receiving
alendronate (and vice versa)."