A single infusion of the bisphosphonate AHPrBP (APD) as treatment of Paget's disease of bone.

PURPOSE

Disabling pain, skeletal deformity, or risk of joint involvement characterize Paget's disease of bone. Because the disease often affects the elderly, for whom compliance is a problem, we investigated therapy with a single intravenous infusion of amino-hydroxypropylidene bisphosphonate (AHPrBP, previously APD).

PATIENTS AND METHODS

Eleven patients with mild but symptomatic Paget's disease and one patient with very severe disease were treated with AHPrBP administered as a single intravenous infusion of 60 mg over 24 hours. Follow-up with clinical and biochemical evaluations was performed over six months for all patients, and over one year for seven patients.

RESULTS

Clinical improvement and normalization of biochemical parameters were observed in all patients except one with extremely severe disease. On average, plasma alkaline phosphatase activity fell progressively and significantly from 256 +/- 29 U/liter (mean +/- SEM) to 97 +/- 6 U/liter after six months, and to 102 +/- 11 U/liter after one year (normal: less than 120 U/liter). Urinary excretion of hydroxyproline decreased within seven days to normal (from 4.3 +/- 0.5 mumol/liter of glomerular filtrate [lGF] to 1.7 +/- 0.2 mumol/lGF; normal: 2.2 mumol/lGF). Thereafter, it remained within the normal range until one year (1.8 +/- 0.2 mumol/lGF after six months and 1.9 +/- 0.3 mumol/lGF after one year). Side effects were negligible. Two patients noted only a transient increase in body temperature. When bone scintigraphy was repeated after six months, it revealed a marked decrease of the activity of the disease.

CONCLUSION

Due to the important and sustained inhibition of bone resorption induced by AHPrBP, a single infusion of 60 mg of the bisphosphonate leads to a rapid decline in activity and a long-standing remission of moderate Paget's disease, without significant side effects.