A selection of resources
A brief guide on neuropathic pain is provided by NICE, who give guidance on sciatica/lower back pain who recommend minimal pharmacological prescriptions for sciatica and for lower back advise against paracetamol alone. Royal College Emergency Medicine has quite clear and useful guidelines on procedural sedation.
There is minimal evidence for effectiveness but they conclude that a percentage of people with neuropathic pain(about 1/4) may be helped.
Minimal effect in short-term, some questionable efficacy in the intermediate term.
More bad news for patients with sciatica; lack of effect demonstrated and with more side effects.