Pain Medications
Acetaminophen, NSAIDs, aspirin and opioids
Compare
| Acetaminophen | NSAIDs | Aspirin | Opioids | |
|---|---|---|---|---|
| Pain | ✓ | ✓ | ✓ | ✓ (moderate–severe) |
| Fever | ✓ | ✓ | ✓ | – |
| Inflammation | – (none) | ✓ | ✓ | – |
| Antiplatelet | – | Temporary | ✓ (irreversible) | – |
| Main danger | Liver | GI bleed, kidneys, heart | Bleeding; Reye's in children | Respiratory depression |
Acetaminophen
- Max 4 g/day in healthy adults (some labels and older adults: 3 g); ≤2 g/day with liver disease or regular alcohol use. It's the preferred pain reliever in cirrhosis at these lower doses.
- Hidden acetaminophen in combination products (cold remedies, hydrocodone/APAP): add them up.
- Overdose may look fine at first; liver failure in 2–3 days. Antidote: acetylcysteine.
NSAIDs (ibuprofen, naproxen, ketorolac, celecoxib)
- Take with food; GI bleeding (black stools, coffee-ground vomit); a PPI may be added.
- Kidney injury (especially with dehydration, ACEi/ARB + diuretic); ↑ BP; ↑ heart attack and stroke risk.
- Ketorolac: max 5 days. Avoid NSAIDs from ~20 weeks of pregnancy unless prescribed.
- Some people with asthma react (aspirin-exacerbated respiratory disease).
Opioids
- morphine, hydromorphone, oxycodone, hydrocodone, fentanyl, methadone, tramadol.
- Assess sedation before respirations: increasing sleepiness comes before respiratory depression (use a sedation scale such as POSS).
- Naloxone: dilute and titrate IV in small doses (e.g., 0.04–0.4 mg) for over-sedation; 4 mg nasal in the community. Watch for return of sedation and for withdrawal and pain.
- Constipation doesn't go away: start a stimulant laxative (senna) with the opioid; softener alone isn't enough.
- Nausea, itching, urinary retention, orthostasis, confusion in older adults.
- Morphine: active metabolites build up in kidney failure (hydromorphone or fentanyl preferred). Avoid meperidine (seizures).
- Tramadol: seizures, serotonin syndrome.
Fentanyl patch
- Only for opioid-tolerant patients with chronic pain. Not for acute pain.
- Change every 72 h; remove the old patch; fold sticky sides together and dispose safely.
- Heat increases absorption (fever, heating pads, hot tubs, saunas): overdose risk.
- Keep away from children and pets (accidental exposure can kill).
New non-opioid option New
Suzetrigine (approved 2025) blocks pain signals in peripheral nerves (NaV1.8) for moderate-to-severe acute pain, without opioid sedation or addiction risk. Many interactions (CYP3A); avoid grapefruit.
Multimodal analgesia
Combine acetaminophen + NSAID + regional techniques + non-drug methods to reduce opioid needs.