My mother experiences a burning feeling in her legs. it is hard for her to sleep at night. she is on pregabalin already. is there any non-prescription pills/cream/patch etc that can help with pain? she has also tried nerviva cream - but not helping?

Dose of pregabalin may need to be increased to have the optimal effect. If she has received 300 mg a day, another medication such as Duloxetine may be added. Topical medications such as Capsaicin and Lidocaine may be tried but the effectiveness is usually limited.

Key issue is the underlying cause of her "burning" pain in her legs. Most likely, it involves a peripheral neuropathy, and cause should be uncovered. Presume a neurologist is involved? If not, should be. A number of symptom relieving interventions could be employed, even using some "off label" approaches.