Drugs

Dose

Duration

Side effect

Reference

1) Gabapentinoids

[31]

- Gabapentin

−1800 - 3600 mg/day

Three times a day, variable titration twice daily,

Diarrhea, dry mouth; warning for increased risk of suicidal thoughts

dizziness, somnolence, peripheral edema

- Gabapentin enacarbil

1200 mg/day

4-day to 1-week titration

- Gastroretentive gabapentin

−1800 mg once daily

2-week titration

- Pregabalin

−150 - 600 mg/day

Two or three times a day; 1-week titration

2) Opioids

[31]

- Tramadol

100 to 400 mg per day

Multiple daily dosing, variable titration

Dependence, nausea, vomiting, anorexia, seizure threshold decreased, sedation, dizziness, confusion, dependence

- Morphine

- Oxycodone

- Methadone

Variable dose and titration

3) Tricyclic antidepressant

[32]

- Amitriptyline

- Desipramine

- Nortriptyline

Up to 150 mg per day

Multiple daily dosing; variable titration

Sedation, dry mouth, blurred vision, constipation, urinary retention

4) Tropical agent and creams

[33]

- Capsaicin 0.075% cream

Applied 3 or four times per day

Every 3 months or longer

Burning skin, Pruritis

- Capsaicin 8% patch

Up to four patches for 1 hour

- Lidocaine 5% patch (Lidoderm)

Maximum three patches per day

Mild skin rxn

5) Ozone therapy

1000 microgram

3 times per week for 4 - 6 weeks

Not much

[34]