Alteration in bone metabolism and bone mineral density with chronic antiepileptic drug therapy

Abstract

Objective: The prolonged usage of antiepileptic medicines has been linked to a reduction in bone mineral density (BMD), resulting in the risk of fracture. However, most evidence has been from western countries, predominantly in institutionalized patients. Furthermore, only a single antiepileptic drug (AED) has been evaluated. This study explores the impact of AEDs on bone health in ambulatory patients from North India. Methodology: A hospital-based observational study on sixty adult patients with epilepsy. All patients were already on AED (valproic acid [VPA], levetiracetam, and phenytoin) either as monotherapy or polytherapy. The serum levels of calcium, phosphorus, alkaline phosphatase, albumin, 25 (OH) Vitamin D, and intact parathyroid hormone were estimated. BMD was assessed at the lumbar spine and femur using a dual-energy X-ray absorptiometry scan. Results: The mean age of patients was 32.75 ± 5.9 years. 56.7% of subjects were female, and 43.3% were male. 40% of patients were taking VPA. Both cytochrome P450 inducing and noninducing AED resulted in a decline in T-score at the lumbar spine (P < 0.01). The BMD declined significantly as the duration of AED intake was prolonged (P < 0.001). Conclusions: In some patients, the intake of AEDs is prolonged, even lifelong. People living with epilepsy are predisposed to falls, and the adverse effects of AED on bone metabolism over time compound the risk of fractures. Thus, the physician needs to monitor all patients on AED for bone health and advise early intervention.

Keywords

• antiepileptic drugs
• bone metabolism
• bone mineral density