1. Trends in Gabapentin Abuse Reported to Poison Centers, 2012-2015
JA Shulman, Lynch MJ, Pizon AF
University of Pittsburgh Medical Center, Division of Medical Toxicology, Department of Emergency Medicine, Pittsburgh, PA
Results:
Identified 6239 cases of gabapentin abuse during the study period (Table 1), and 9663 coingested substances (Table 1), among which sedative-hypnotics were most common.
Males comprised 48.5% of reported cases, ages 39.3±14.8 years
Sole agent of abuse in 2195 cases (35.2%), and symptoms related to drowsiness/lethargy in cases of only gabapentin abuse were most common (Table 2).
Mean annual prevalence of gabapentin abuse rose from 2.69 cases per million (CPM) in 2012 to 9.18 CPM in 2015 (Figure 1)
West Virginia and Kentucky had highest average prevalence during this period (Figure 2)
22 reported deaths, only 1 from gabapentin alone, 95% were associated with other substances
Background
Gabapentin is a newer antiepileptic medication with structural homology to GABA, though mechanism of action is dissimilar
In overdose, reported to cause euphoria and sedation,
Good candidate for drug abuse.
Due to widespread rise in availability and abuse potential, we predicted to find a rise in rates of gabapentin abuse reported to U.S. Poison Centers
Methods
Retrospective analysis of adult (>17 years) cases reported to the National Poison Data System (NPDS) from 1/2012 to 12/2015 using search terms, “gabapentin,” “abuse”
Information on demographics, outcomes, and interventions were collected
All analyses performed using descriptive statistics
Courtesy: National Geographic
Discussion/Conclusions
Rates of gabapentin abuse reported to poison centers have risen steadily between 2012 and 2015 in every state.
Very few fatalities in isolation, however usually combined with other more lethal dangerous substances.
Factors which may influence abuse include:
Difficulty in detection on routine drug screening
Lack of DEA schedule designation
Future areas of investigations include association with other substances implicated in abuse.
Coingested
Substance
Reported (n=9663)
Sedative-hypnotic
3684
Opioids
1702
Antidepressants
916
Non-opioid Analgesics
507
Antiepileptics
451
Antihistamines
413
Antihypertensives
314
Sympathomimetics
302
Hallucinogenic Compounds
205
Cough/Cold 33
Other
1136
Symptom
Number Related
% of total (n=2195)
Drowsiness/lethargy
1027
16.5
Tachycardia
316
5.1
Slurred speech
219
3.5
Confusion
212
3.4
Agitated/irritable
179
2.9
Hypotension
128
2.4
Ataxia
124
2.0
Coma
117
1.9
Hypertension
112
1.8
Respiratory Depression
104
1.7
Dizziness/vertigo 87
1.4
Figure 1: Mean cases per state (in CPM) of gabapentin abuse exposures reported to poison centers
Table 3: Symptoms in gabapentin abuse cases most frequently reported to U.S. Poison Centers thought to be related to gabapentin abuse alone (n=2195) as reported in NPDS from
Table 1: Coingested substances reported to NPDS from
2012
2014
2013
2015
CPM
Figure 2: Population-adjusted heat maps demonstrating changes in cases reported to U.S. poison centers (cases per million) each year between 2012 and 2015
Special Thanks to Jessica Kerr for her assistance in creating this poster