Objective To explore the effects of new antiepileptic drugs levetiracetam (LEV) and lamotrigine (LTG) on bone mineral density, cognitive function, and sleep breathing in elderly patients with epilepsy. Methods A total of 112 elderly patients with new-onset epilepsy admitted to the First Affiliated Hospital of Hainan Medical University from January 2024 to June 2024 were selected as study subjects. They were divided into an LEV group (n=38), an LTG group (n=38), and a carbamazepine (CBZ) group (n=36) by a random number table method. All three groups of elderly patients with new-onset epilepsy were treated with monotherapy for 6 months. The three groups were compared in the clinical efficacy and bone mineral density (BMD), serum indicators [intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), brain-derived neurotrophic factor (BDNF)], cognitive function [mini-mental state examination (MMSE)], and sleep breathing parameters [apnea hypopnea index (AHI), mean arterial oxygen saturation (MSaO₂), lowest arterial oxygen saturation (LSaO₂)] before treatment and after 6 months of treatment. The incidence of adverse reactions during treatment was assessed. SPSS 25.0 was used for data analysis. According to the data type, one-way analysis of variance or Chi-square test was used for comparison between groups. Results The effective rates of treatment in the LEV group, LTG group, and CBZ group were 89.47%, 86.84%, and 86.11%, respectively, with no statistically significant difference (P>0.05). There were no statistical differences in femoral neck and greater trochanter BMD and MSaO₂ among the three groups before and after treatment (P>0.05). After 6 months of treatment, lumbar spine BMD and AHI in the three groups decreased compared with those before treatment, while iPTH, ALP, BDNF, MMSE score and LSaO₂ significantly increased compared with before treatment. Furthermore, lumbar spine BMD, BDNF, MMSE scores, and LSaO₂ in the LEV group and LTG group after treatment were higher than those in the CBZ group, while iPTH, ALP, and AHI after treatment were significantly lower than those in the CBZ group, all differences being statistically significant (P<0.05). The total incidence rates of drug-related adverse reactions in LEV group, LTG group and CBZ group were 7.89%, 7.89%, and 11.11%, respectively, with no statistically significant difference (P>0.05). Conclusion For elderly patients with new-onset epilepsy, LEV, LTG and CBZ monotherapy for 6 months all demonstrate good efficacy with few adverse reactions. However, the new antiepileptic drugs LEV and LTG have greater advantages in improving cognitive function, alleviating sleep-disordered breathing, and reducing the impact on bone metabolism.