Acetaminophen
Acetaminophen (paracetamol)
Brand names:Tylenol, Panadol, Ofirmev (IV formulation)
A non-opioid analgesic and antipyretic that works centrally to reduce pain and fever without significant anti-inflammatory effects. Component of the TCCC Combat Wound Medication Pack (CWMP) since 2007 and retained through the 2026 update for mission-capable casualties.
Pharmacology and Actions
Acetaminophen's exact mechanism remains incompletely understood, but its analgesic and antipyretic effects appear to result from inhibition of central nervous system prostaglandin synthesis and modulation of descending serotonergic pain pathways. Unlike NSAIDs, acetaminophen has minimal peripheral cyclooxygenase inhibition, which is why it has weak anti-inflammatory effects but does not impair platelet function or irritate gastric mucosa.
The drug is metabolized primarily by hepatic glucuronidation and sulfation, with a small fraction processed through CYP2E1 to a toxic intermediate (NAPQI) normally detoxified by glutathione. In overdose, glutathione depletion allows NAPQI to cause hepatocellular necrosis. This mechanism is the basis for the toxicity profile and the rationale for N-acetylcysteine as antidote.
Indications
- Mild to moderate pain in mission-capable casualties (TCCC 2026 CWMP)
- Fever reduction
- Adjunct analgesia in multimodal pain management
- Pain control when NSAID use is contraindicated
Absolute Contraindications
- Known acetaminophen allergy
- Severe active hepatic disease
- Active acetaminophen toxicity
Precautions and Side Effects
Generally well-tolerated at therapeutic doses. Hepatotoxicity is dose-dependent and occurs at acute doses above 7.5 to 10 grams in adults, or chronic daily doses above 4 grams.
Use caution in patients with chronic alcohol use, malnutrition, or pre-existing hepatic impairment. The toxic threshold is lower in these populations.
Maximum daily dose for healthy adults is 4 grams in 24 hours. The TCCC CWMP regimen of 1000 to 1300 mg every 8 hours stays within this limit.
Skin reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis have been reported but are rare.
Adult Dosing
IV formulation (Ofirmev) is rarely available in tactical or prehospital settings.
Onset: 5 to 10 minutes
Take with the other CWMP components: meloxicam 15 mg PO once daily and either suzetrigine 50 mg PO every 12 hours (preferred) or moxifloxacin 400 mg PO once daily for wound prophylaxis.
Standard EMS: 650 to 1000 mg PO every 4 to 6 hours, not to exceed 4 grams in 24 hours.
Onset: 30 to 60 minutes
Pediatric Dosing
Hospital / Emergency Department: 1000 mg IV over 15 minutes every 6 hours, not to exceed 4 grams in 24 hours
IV formulation (Ofirmev) is rarely available in tactical or prehospital settings.
Pharmacokinetics
Peak Effect: PO: 1 to 2 hours
IV: 15 to 30 minutes
Duration: 4 to 6 hours
Storage and Handling
Store at room temperature (15 to 30 degrees Celsius). Protect from light and moisture. Most TCCC CWMP packs are designed for ambient storage in standard military operating environments.
The CWMP itself is supplied as a pre-packaged blister card containing all components in a single dose. Individual blister cards are stable for the duration printed on the package, typically 2 to 3 years from manufacture.
Liquid acetaminophen formulations are temperature-sensitive and not suitable for tactical pack storage. Tablet form is the standard.
Reconstitution:
Tablet form requires no reconstitution.
IV formulation (Ofirmev) is supplied as a 10 mg/mL ready-to-use solution in a 100 mL vial. Do not dilute. Administer over 15 minutes via dedicated IV line.
TCCC and TECC Role
Acetaminophen is the foundational analgesic in the TCCC Combat Wound Medication Pack, retained without change through the 2026 guidelines update. The CWMP regimen pairs acetaminophen with meloxicam (NSAID component) and either suzetrigine (preferred non-opioid analgesic addition) or moxifloxacin (wound infection prophylaxis when oral antibiotics are indicated).
The drug's value in tactical medicine comes from what it does NOT do: it does not impair platelet function, does not depress respiration, does not cause sedation or dissociation, and does not affect mental status. A casualty taking CWMP acetaminophen remains fully mission-capable. This is why the CWMP is administered to ambulatory casualties who can continue movement and self-defense.
The 2026 TCCC update emphasizes early CWMP administration when the casualty's tactical situation permits oral medication. Casualties who can take pills should receive CWMP regardless of whether they are also receiving more potent analgesics.
Acetaminophen is the workhorse analgesic that almost every casualty can safely receive. It is commonly under-utilized in tactical medicine because it lacks the dramatic effect of opioids or ketamine, but its value comes from being administrable to the widest range of casualties without impairing operational capability.
The CWMP regimen is designed to be self-administered or buddy-administered while moving casualties off the X. A casualty who takes the CWMP at the time of injury and continues movement to evacuation will have meaningful analgesia onboard by the time more aggressive interventions become available.
A common operational pattern: casualty takes CWMP at injury, completes self-evac to CCP, receives suzetrigine or low-dose ketamine if pain is inadequately controlled, then arrives at Role 2 with multimodal analgesia onboard and minimal opioid burden.
Withholding CWMP because the casualty seems "not that bad" or because more potent analgesics are available. The CWMP is part of immediate care for any wounded casualty who can take oral medication, not a backup plan. Early administration matters because oral onset takes 30 to 60 minutes, and you want analgesia onboard before pain peaks.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
If this content is being viewed during a medical emergency, call 911 immediately and follow the direction of your local emergency dispatch and medical control. Do not use this reference as a substitute for emergency medical services.
Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Acetaminophen
| IV/IO | Hospital / Emergency Department: 1000 mg IV over 15 minutes every 6 hours, not to exceed 4 grams in 24 hours IV formulation (Ofirmev) is rarely available in tactical or prehospital settings. (5 to 10 minutes) |
| PO | TCCC 2026 CWMP: 1000 to 1300 mg PO every 8 hours Take with the other CWMP components: meloxicam 15 mg PO once daily and either suzetrigine 50 mg PO every 12 hours (preferred) or moxifloxacin 400 mg PO once daily for wound prophylaxis. Standard EMS: 650 to 1000 mg PO every 4 to 6 hours, not to exceed 4 grams in 24 hours. (30 to 60 minutes) |