Table I.
Summary of clinical studies on topical lidocaine for the treatment of DNP.
| Author, year | Topical agent(s) | Study design | No. of patients (% male) | Age, years (mean ± standard deviation) | Duration of pain | Outcomes | (Refs.) |
|---|---|---|---|---|---|---|---|
| Comparisons with oral pregabalin | |||||||
| Baron et al, 2009 | 5% Lidocaine plaster | Two-stage, adaptive, randomized, controlled, open-label, 4-week, multicenter trial that incorporated a drug wash-out phase of up to 2 weeks prior to the start of the comparative phase | Lidocaine: 47 (48.9) Pregabalin: 44 (54.5) | Lidocaine: 60.2±9.9 Pregabalin: 59.8±8.4 | ≥3 months | Showed similar analgesic efficacy, fewer DRAEs (3.9% vs. 39.2%) and fewer substantial discontinuations due to DRAEs (1.3 vs. 20.3%) than pregabalin. | (59) |
| Baron et al, 2009 | 5% Lidocaine plaster | Two-stage adaptive, randomized, open-label, 4-week, multicenter, non-inferiority study | Lidocaine: 105 (42.9) Pregabalin: 105 (46.7) | Lidocaine: 60.9±10.0 Pregabalin: 60.9±8.8 | ≥3 months | Showed comparable efficacy, greater improvements in QOL, and fewer AEs, DRAEs and related discontinuations compared with pregabalin. An 8-week combination phase of this study demonstrated additional decreases in NRS-3 scores. | (52,60) |
| Noncomparative studies | |||||||
| Barbano et al, 2004 | 5% Lidocaine patch | Open-label, flexible-dosing, 3-week study with a 5-week extension | 56 (NA) | NA | ≥3 months | Significantly reduced pain and improved QOL. These benefits were maintained during an additional 5 weeks with tapering of concomitant analgesics. | (56) |
| Argoff et al, 2004 | 5% Lidocaine patch | Open-label, non-randomized, prospective, 2-week study | 41 (41.5) | 56.7±12.6 | NA | Effectively reduced the intensity of pain in patients with DNP. Well tolerated in combination with other analgesic regimens. No serious AEs or adverse drug interactions. | (55) |
| White et al, 2003 | 5% Lidocaine patch | Open-label, non-randomized, 2-week multicenter pilot trial. | 49 (46.9) | 57.7±12.6 | NA | Improved pain intensity and pain relief scores. | (61) |
DNP, diabetic neuropathic pain; AE, adverse event; DRAE, drug-related adverse event; QOL, quality of life; NA, not available.