Table 1.
Overview of the included literature
| Study | Country | Publication year | Study type | Age (years) | Pain score | Intervention/control | Treatment details | Cases |
|---|---|---|---|---|---|---|---|---|
| Levendoglu F | Turkey | 2004 | 18-week, randomized, controlled, double-blind, crossover clinical trial | 20–65 | NRS > 4 | GBP/placebo | 4-week titration period (gabapentin or placebo) followed by a 4-week stable dosing period, 2-week washout period and then cross over to the alternative treatment plan for 4 weeks titration and 4 weeks stable dose | 20/20 |
| Siddall | Australia | 2006 | 12-week, randomized, controlled, multicenter, parallel group, double-blind clinical trial | ≥ 18 | NRS ≥ 4 | PGB/placebo | Pregabalin or placebo was initiated at 150 mg/day for the 1 week and then increased to 300 mg/day, the dose could be further increased to 600 mg/day after the second week if needed for efficacy | 70/67 |
| Rintala | American | 2007 | Randomized, controlled, double blind, triple-crossover clinical trial | 18–70 | NRS ≥ 5 | Amitriptyline/GBP/placebo | Amitriptyline 3 times daily, maximum doses 50 mg; gabapentin 3 times daily, maximum doses 1200 mg; placebo (diphenhydramine) 3 times daily, maximum doses 25 mg | 36/36/36 |
| Vranken | Netherlands | 2008 | 4-week, randomized, double-blinded, placebo-controlled trial | ≥ 18 | VAS > 6 | PGB/placebo | Pregabalin (150, 300 and 600 mg/day) or placebo (daily orally intake of 1, 2, or 4 capsules) titrated at 3-day intervals based on response and tolerability | 20/20 |
| Cardenas DD | Chile, China, Columbia, Czech Republic, Hong Kong, India, Japan, Philippines, Russian Federation, USA | 2013 | 17-week, randomized, double-blind, placebo-controlled trial | ≥ 18 | NRS ≥ 4 | PGB/placebo | Pregabalin or placebo initially received 150 mg/day for 7 days, increased to 300 mg/day on day 8, 450 mg/day on day 15, and 600 mg/day on day 22. 12-week maintenance period, 1-week period tapered off | 112/107 |
| Yilmaz B | Turkey | 2014 | 18-week, prospective, crossover, randomized clinical trial | 32.93 ± 11.87 | VAS | GBP/PGB | Gabagentin was administered orally 3 times a day, dosages were titrated to tolerability up to 1800 mg/day; pregabalin was administered 2 times a day, dosages were titrated to tolerability up to 300 mg/day | 30/30 |
| Kaydok E | Turkey | 2014 | Prospective, randomized, single blind, cross-over study | 18–70 | VAS ≥ 4 | PGB/GBP | Gabapentin 300–3600 mg/day, orally 3 times a day, pregabalin 150–600 mg/day, orally 2 times a day | 28/28 |
| Yang X | China | 2020 | 4-week, randomized controlled trial | 57.13 ± 2.85 | VAS > 3 | PGB/carbamazepine | Carbamazepine 1–3 mg, orally 2 times/day, pregabalin 150–300 mg/day, orally 2 times/day | 43/43 |