Acetaminophen levels 4 and 7 hours after 2000 and 3000 mg single doses in healthy adults.
OBJECTIVE
Therapeutic acetaminophen levels are not achieved at currently recommended doses. The purpose of this study is to determine acetaminophen levels in healthy adults after taking a single dose well in excess of the recommended dose.


METHODS
24 healthy adults received single 2 or 3 gram acetaminophen doses. Serum acetaminophen levels were drawn at 4 and 7 hours after the dose.


RESULTS
The 2 gram doses (6 subjects) ranged from 23 to 40 mg/kg of body weight. The 3 gram single doses (18 subjects) ranged from 38 to 69 mg/kg of body weight. Mean 4-hour acetaminophen levels for 2 and 3 gram doses were 8.8 (SD 3.6, range 3-13) and 21.8 (SD 6.5, range 6-32) mcg/ml, respectively. Mean 7-hour acetaminophen levels for 2 and 3 gram doses were 1.5 (SD 1.4, range 0-3) and 7.7 (SD 4.6, range 0-17) mcg/ml, respectively.


CONCLUSIONS
Dosing by weight (i.e., mg/kg) appears to provide a more predictable dose-response relationship. Optimal adult dosing appears to be somewhere in the 20 to 30 mg/kg range based on the premise that the 4 hour level is a trough level that should be in the low therapeutic range.
Sumida
Shawn M
SM
Department of Pediatrics, University of Hawaii John. A. Burns School of Medicine, 1319 Punahou Street, 7th Floor, Honolulu, HI 96826, USA.
Sato
Renee L
RL
Wong
Jeffrey J
JJ
Yamamoto
Loren G
LG
D000082:Acetaminophen / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D013997:Time Factors
D000082:Acetaminophen