Acetaminophen

TYLENOL

Open Acetaminophen in the interactive console ↗

Pronunciation: a-set-a-MEE-noe-fen

Acetaminophen ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Acetaminophen ballicule

Acetaminophen PARACETAMOL / APAP / TYLENOL mascot mnemonic cartoon — Visual mnemonic: Acetaminophen mascot
**“I see the mini fin, a Pair a’ aces, A papule, Tile ‘n’ all”**
“I see the mini fin” = acetaminophen
“Pair a’ aces” = paracetamol
“A papule” = APAP
“Tile n’ all” = Tylenol

What it isTRPV1 agonist and central COX inhibitor with little anti-inflammatory activity; pain and fever.

Why this oneUnlike NSAIDs, it does not inhibit platelets or meaningfully inflame the stomach, making it useful with anticoagulation.

What limits itWeaker analgesic than NSAIDs; stacked combination products drive overdose. Lower the ceiling in liver disease or heavy drinking.

Pearls

Ceiling 4 g/day in healthy adults; regular use can still raise transaminases.
Regular 4 g/day modestly raises blood pressure in hypertension.
NSAID plus acetaminophen can match opioid combinations for acute pain.
IV acetaminophen not recommended for severe migraine in the ED.

Acetaminophen molecular structure (skeletal formula) — Molecular structure: Acetaminophen

FDA-approved for

pain/fever (~1951)

Principal riskHepatotoxicity in overdose, and from stacked combination products

Classes and tags

Clinical profile

Therapeutic safety burden1 / 4

Overdose danger4 / 4

Weight-gain liability0 / 4

Sedation liability0 / 4

QT / Torsades0 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk1 / 4

Legacy pregnancy categoryB

Defining liabilityUsually well tolerated therapeutically; overdose may cause delayed fulminant hepatic failure.

FDA label

Read the full label on DailyMed ↗

NO BOXED WARNINGS

Dosing under review against the product label.

Available strengths

ER tab 650 mg
cap 325, 500, 650 mg
tab 0.5 g/g
tab 160, 325, 500, 650 mg
ODT 160 mg
chew tab 80, 160, 250 mg
powder 160 mg
powder 500 mg/.95 g
+ 15 other marketed forms not shown

Contraindications

With any other drug containing acetaminophen (Rx or OTC)

Cautions

Liver warning: severe liver damage if >4,000 mg/24 h, with other acetaminophen drugs, or ≥3 alcoholic drinks/day
Allergy alert: severe skin reactions (reddening, blisters, rash) — stop use and seek help
Ask a doctor before use if liver disease
Ask a doctor/pharmacist before use if taking warfarin
Stop use if pain worsens or lasts >10 days, fever worsens or lasts >3 days, new symptoms, or redness/swelling

Pregnancy If pregnant, ask a health professional before use (Drug Facts).

Lactation If breast-feeding, ask a health professional before use (Drug Facts).

Cost

Acetaminophen (TYLENOL)

What pharmacies pay · NADAC 9/30/26 · OTC

Strength		#/mo	generic $/unit	CostPlus
650 mg	ER tab	per unit	$0.06/ea	not offered

Available combined with: Codeine (in TYLENOL #3) · acetaminophen / codeine · butalbital / acetaminophen / caffeine · hydrocodone / acetaminophen · oxycodone / acetaminophen

Generic entry1986