What it means
An analgesic is a medicine that relieves pain. From the Greek an-, without, and algos, pain — the same root as -algia.
The main classes work by entirely different mechanisms:
- Paracetamol — acts centrally; mechanism still not fully understood
- NSAIDs — reduce inflammation at the site of injury
- Opioids — act on opioid receptors in the brain and spinal cord
- Neuropathic agents such as amitriptyline and gabapentin — calm overactive nerve signalling
Because the mechanisms differ, combining paracetamol with an NSAID gives better relief than a higher dose of either, and this is often overlooked.
In practice
The WHO analgesic ladder describes stepping up from simple analgesics to weak and then strong opioids, though it was designed for cancer pain and applies poorly to chronic non-cancer pain.
"Analgesia" refers to pain relief itself; "analgesic" to the medicine.
Why it matters
Neuropathic pain — burning, shooting, electric-shock pain from nerve damage — responds poorly to paracetamol, NSAIDs and opioids alike, and needs a different class entirely.
We do not prescribe opioid painkillers remotely, without exception. Regular painkiller use for headache can itself cause daily headache, which resolves only on stopping.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026