It is typically prescribed for moderate-to-severe pain where other painkillers have failed or cannot be used: Musculoskeletal Pain: Severe back pain, neck pain, and muscle spasms. Neuropathic Pain: Nerve-related pain like sciatica. Post-Surgical Pain: Recovery after orthopedic or general surgery. Chronic Tension Headaches: When standard treatments aren't effective.

It works by opening potassium channels in the nerve cells. This "quiets" the overexcited nerves, effectively blocking pain signals from reaching the brain and relaxing tense muscles without affecting general muscle strength.

While it avoids many common painkiller side effects (like constipation or gastric bleeding), it has one major risk: Hepatotoxicity (Liver Damage): This is the most serious risk. Signs include yellowing of eyes/skin (jaundice), dark urine, and abdominal pain. Common Side Effects: Drowsiness, dizziness, dry mouth, nausea, and fatigue. Urine Color: It may cause a harmless green discoloration of the urine.