Oral gabapentin and intradermal injection of lidocaine: is there any role in the treatment of moderate/severe tinnitus?

The objective of our work is to evaluate recovery induced by gabapentin alone and in association with intradermal infiltration of lidocaine in patients affected by moderate/severe tinnitus. Seventy-two patients suffering from moderate/severe unilateral non-pulsatile subjective tinnitus were enrolled. Severity and behaviour of tinnitus were assessed by Tinnitus handicap Index (THI) on the 8th, 22nd and 36th days from onset of therapy, and on the 3rd and 6th month after the end of therapy in patients treated with oral gabapentin (Group I), oral gabapentin and intradermal injection of lidocaine (Group II), and placebo (Group III) Significant differences in THI scores from the 8th day of therapy to the 22nd (p < 0.0001) and from the 22nd day to the 36th (p = 0.0002 and p = 0.0004, respectively) were found in Group I and Group II. In Group II, another relevant decrease of THI scores from the 36th day of therapy to 3 months from the end of treatment (p = 0.0004) was found. A significant difference in THI scores between Group I and Group II was found after 8 days of treatment (p = 0.05) with a more relevant decrease registered in Group II; significant differences were also found in THI scores between Group I and Group III after 8 days of treatment (p = 0.01), with a more relevant decrease registered in Group III; significant differences in THI scores between Group II and Group III were found after 36 days of treatment (p = 0.009), 3 and 6 months after the end of therapy (p = 0.005 and p = 0.007, respectively), with a more relevant decrease registered in Group II. In conclusion, the use of gabapentin associated to lidocaine seems to be superior to placebo and gabapentin in relieving tinnitus.