Objective:

To investigate the analgesic efficacy and safety of 5% lidocaine gel in painful HIV-associated distal sensory polyneuropathy (DSP).

Background:

Painful DSP, the most common neurologic complication in HIV infection, is difficult to treat. Lidocaine 5% gel was effective in alleviating neuropathic pain in an open-label study of HIV DSP.

Methods:

In a double-blind, placebo-controlled, crossover, multi-center study, 64 subjects were randomized to receive 5% lidocaine or vehicle gel for 2 weeks (phase A). A washout period of 2 weeks was followed by a crossover to the alternate agent for another 2 weeks (phase B). The primary outcome was difference in average pain scores (Gracely pain scale) between the 2 groups during the second week of each treatment period. Secondary outcomes included differential effect of the first treatment, difference in global pain relief, and pain response by neurotoxin exposure.

Results:

The baseline pain scores of the 2 groups were similar. The average pain scores during the second week of each phase of the lidocaine gel group did not differ from those of the placebo group (phase A: lidocaine 1.09, placebo 1.15; phase B: lidocaine 1.16, placebo 1.10). There also was no difference noted in secondary outcomes. The pain responses of lidocaine gel-treated subjects with current exposure to neurotoxic antiretrovirals (1.18) did not differ compared with those without (1.10)(P= 0.358). There were no significant adverse effects.

Conclusion:

Lidocaine 5% gel is a safe but ineffective agent in the treatment of pain in HIV-associated DSP.