Acetaminophen Overdoses:

A Review of Intentional and Unintentional Cases

Hospital of the University of Pennsylvania

Philadelphia, PASarah Erush, PharmD, BCPS

Karen Shalaby, PharmD

Hospital of the University of Pennsylvania 700 bed tertiary academic medical facility

Level I Trauma Center/Transplant Services

Serves tri-state region

Averages 35,000 admissions per year

No pediatric admissions

Adverse Drug Event Program

Operated by Drug Information Service

Averages 600 reports per year

Spontaneous and targeted reporting methods

Acetaminophen overdoses reported despite recommendations otherwise

Unintentional overdose trend noted

Acetaminophen Case Series1998 – 2002 YTD

54 Reports

52 Charts Received

49 Reviewed

47 Acetaminophen

23 Intentional

23 Unintentional1

unknown

3 Incomplete

2 Not Acetaminophen

Psychiatry Consult Service

13/23 (56%)0/23 (0%)No Request:

10/23 (44%)23/23 (100%)

Request:

UNINTENTIONALINTENTIONAL

Patient Demographics

0102030

40506070

Age Male Female Direct Adm Transfer

(Characteristic)

(Yea

rs/%

)

Intentional Unintentional

Acetaminophen Dose

1.1 to 180.5 to 101Range (gm/day)

6.415.6Median (gm/day)

8.132Average(gm/day)

8/23 (34%)10/23 (43%)Known

15/23 (65%)13/23 (56%)Unknown

UNINTENTIONALINTENTIONAL

Acetaminophen Formulation

INTENTIONAL RX = 3

Percocet n=2 Darvocet n=1

OTC =21 Single Entity n=8 Combo Entity

n=13

UNINTENTIONAL RX = 3

Percocet n=2 Darvocet n=1

OTC = 20 Single Entity n=15 Combo Entity n=5

Causality: Unintentional Cases

9%

13% 18%

36%

PainToothacheInsomniaHeadacheHeadache/ Hip PainMenstrual CrampsHangoverFeverPruritusUnknown

Acute Exposure (< 7 days)

0

20

40

60

80

100

1 2 3 4 5 6

Days

%

Intentional n=22/ 23 Unintentional n=14/ 23

Lab Results: Average Peak Levels

INTENTIONAL UNINTENTIONAL

APAP: 115.1 mg/L 27.8 mg/L

ALT: 3,065 units/L 5,193 units/L

AST: 2,742 units/L 6,819 units/L

INR: 2.5 4

T Bili: 1.87 mg/dL 5.87 mg/dL

Length of Stay

65Median

2 to 302 to 55Range

8.97.4TOTAL Days: Average

1 to 101 to 16Range

43Median

4.43.6ICU Days: Average

UNINTENTIONALINTENTIONAL

Patient OutcomeINTENTIONAL UNINTENTIONAL

Resolved: 22/23 (96%) 16/23 (69%)

Evaluated: 9/23 (39%) 11/23 (48%)

Transplant: 0/23 (0%) 2/23 (9%)

Death: 0/23 (0%) 3/23 (13%)

Transplant and Death:

1/23 (4%) 0/23 (0%)

Risk FactorsINTENTIONAL

UNINTENTIONAL

Hepatic Disease:

1/23 (4%) 2/23 (9%)

Alcohol Use: (Acute or Chronic)

14/23 (61%) 20/23 (87%)

Drug Abuse:(Current or

Past)

10/23 (43%) 8/23 (35%)

Concomitant Disease:

1/23 (4%) 3/23 (13%)

Alcohol Use

2/23 (9%)1/23 (5%)Unknown:

6/23 (26%)10/23 (44%)None:

6/23 (26%)3/23 (13%)Acute with Chronic:

0/23 (0%)2/23 (8%)Acute:

9/23 (39%)7/23 (30%)Chronic:

UNINTENTIONALINTENTIONAL

Multiple Risk Factors

0

2

4

6

8

10

12

0 1 2 3 4

# of Risk Factors

# o

f Pati

ents

I ntentional 16/ 23 Unintentional 22/ 23

Data Summary Unintentional overdoses accounted for 50%

cases

Doses are lower and ingested over 1 to 3 days

Unintentional cases had greater toxicity when judged by LFT, INR, and length of stay

Unintentional cases had higher transplant and death rates

Data Summary cont. Influence of risk factors remains unclear

Hospital Costs (mean) Intentional: $12,671

Unintentional: $23,380

Extrapolated Cost Data

Results similar to those previously published

Recommendations

Continue availability of OTC Acetaminophen

Education of healthcare practitioners Encourage reporting of acetaminophen

overdoses Awareness of unintentional overdoses

Education of patients Awareness of potential toxicity

Recommendations cont. Labeling

Maximum dose and duration Combination products

Packaging Limit purchase size Consider unit dose application

Manufacturing Consider addition of N-Acetylcysteine to

Acetaminophen preparations.

Quote

“If I had known it would make me this sick, I never would have taken it”