Comparative analysis of the effectiveness of Lidocaine and Carbamazepine on subjective tinnitus in the elderly

Objective To study the effectiveness of intravenous Lidocaine on subjective tinnitus in the elderly, and analyze its correlation with the effectiveness of subsequently oral Carbamazepine. Methods A prospective case-control study was conducted in 120 elderly patients with subjective tinnitus, who were divided into two groups. The control group (n=60) was treated with oral Carbamazepine 0.1 g Bid for one month, and the treatment group (n=60) was treated with 2% lidocaine by intravenous injection. Patients in the treatment group were observed on responses in tinnitus during the period with Lidocaine injections. The treatment group was further divided into the improvement subgroup and the no-improvement subgroup, according to responses to intravenous lidocaine. All the patients in the treatment group received oral carbamazepine 0.1 g Bid for one month following the intravenous lidocaine injection phase. Results In the control group, 5 patients showed marked improvement, 20 patients showed partial improvement, 33 patients showed no improvement, and 2 patients showed symptom deterioration, with an effectiveness rate of 41.7% (25/60). In the treatment group, 6 patients showed marked improvement, 26 patients showed partial improvement, 24 patients showed no improvement, and 4 patients showed symptom deterioration, with an effectiveness rate of 53.3% (32/60). Of the 32 patients in the improvement subgroup, 6 cases showed marked improvement, 16 cases showed partial improvement, 8 cases showed no improvement, and 2 cases showed symptom deterioration after subsequent oral Carbamazepine treatment, and the effectiveness rate was 68.8% (22/32). Of the 28 patients in the no-improvement subgroup, 1 case showed marked improvement, 9 cases showed partial improvement, 16 cases showed no improvement, and 2 cases showed symptom deterioration, and the effectiveness rate was 35.7% (10/28). The effectiveness rate in the improvement subgroup was higher than in the no-improvement subgroup (68.8% vs. 35.7%, χ2=6.55, P<0.05). The effectiveness of lidocaine followed by carbamazepine was better than that of carbamazepine alone (68.8% vs. 53.3%, χ2=6.13, P<0.05). Conclusions Oral Carbamazepine treatment following intravenous Lidocaine injection in elderly patients with subjective tinnitus has better therapeutic outcomes than treatment with oral Carbamazepine alone, but is not as effective in patients with negative responses to Lidocaine as in patients with positive responses. Key words: Tinnitus; Lidocaine; Carbamazepine