The Many Faces of Pain
How Doctors Choose Between NSAIDs, Acetaminophen, Opioids, and Nerve Pain Medications
Pain is a universal experience, but it is not a uniform one. The biological mechanisms of pain vary widely, and the choice of medication must match the specific type of pain. A doctor does not simply prescribe “a painkiller”; they select a tool based on the pain’s origin, intensity, duration, and the patient’s individual risk profile. Using the wrong class of medication can mean inefficacy, unnecessary side effects, or in the case of opioids, significant risk.
The first distinction is between nociceptive pain and neuropathic pain.
Nociceptive pain is the normal, healthy response to tissue injury. It’s the pain of a sprained ankle, a surgical incision, or osteoarthritis. This pain travels along a normal, intact nervous system. The treatment ladder for nociceptive pain is well-established by the World Health Organization:
Mild Pain: The first line is acetaminophen (paracetamol) or a nonsteroidal anti-inflammatory drug (NSAID) like ibuprofen or naproxen. The choice between them depends on context. Acetaminophen is safer for the stomach and kidneys but has no anti-inflammatory effect. NSAIDs are superior for inflammatory pain (like a sprain or arthritis) but carry risks of gastrointestinal bleeding, kidney injury, and, with chronic use, cardiovascular events.
Moderate Pain: If acetaminophen or NSAIDs are insufficient, the next step is often a combination of these with a weak opioid, such as codeine or tramadol, or a combination product like hydrocodone/acetaminophen.
Severe Pain: For severe acute pain (post-surgery, trauma, cancer), stronger opioids like morphine, oxycodone, or hydromorphone are used, typically for short durations.
Neuropathic pain is a completely different animal. This pain arises from damage or dysfunction within the nervous system itself. It is described as burning, shooting, electric shock-like, or “pins and needles.” Common conditions include diabetic neuropathy, postherpetic neuralgia (shingles pain), and sciatica. For this type of pain, opioids and NSAIDs are notoriously ineffective. The first-line treatments are instead:
Gabapentinoids: Gabapentin and pregabalin (Lyrica), which calm overactive nerve signaling.
Antidepressants: Specifically, SNRIs like duloxetine (Cymbalta) and TCAs like nortriptyline. These drugs modulate pain pathways in the central nervous system, independent of their mood effects.
The Opioid Question:
In recent years, the approach to opioids has undergone a dramatic shift due to the opioid crisis. For chronic non-cancer pain, opioids are now considered a last-line, not a first-line, treatment. The risks of dependence, tolerance, and overdose are now weighed far more heavily than in the past. When opioids are prescribed for acute pain, the guiding principles are:
Lowest effective dose.
Shortest possible duration (often 3–7 days).
Clearly defined goals for pain and function.
The choice of a pain medication is a decision about matching mechanism to mechanism. Treating nerve pain with an NSAID is as futile as treating a sprained ankle with gabapentin. By correctly identifying the type of pain, a clinician can select the drug that offers the greatest chance of relief with the lowest risk of harm.