Medicines are commonly prescribed for the treatment of sciatica, but evidence for pain medication is poor.  Specifically, low-quality evidence indicates that NSAIDs do not appear to improve immediate pain and all NSAIDs appear about equivalent.    Evidence is also lacking in use of opioids and muscle relaxants by usual means.  In those with sciatica due to piriformis syndrome, botulinum toxin injections may improve pain and or function.  There is little evidence for steroids, either epidural or by pill.   Low-quality evidence supports the use of gabapentin for acute pain relief in those with chronic sciatica. 
The most common cause of sciatica is a bulging or ruptured disc ( herniated disc ) in the spine pressing against the nerve roots that lead to the sciatic nerve. But sciatica also can be a symptom of other conditions that affect the spine , such as narrowing of the spinal canal ( spinal stenosis ), bone spurs (small, bony growths that form along joints) caused by arthritis , or nerve root compression ( pinched nerve ) caused by injury. In rare cases, sciatica can also be caused by conditions that do not involve the spine, such as tumors or pregnancy .