Using Pharmacology to Get a Better High

The abuse of prescription and non-prescription medication has increased and continues to impact drugged driving. The issue of drugged driving is a complex problem that is further complicated by evolving pharmacology and the struggle of toxicology to catch up. Pharmacology is entrenched in every poly-category drugged driving arrest. The understanding of how drugs interact with one another and the signs and symptoms a user may exhibit is critical information to a DRE. For example, the use of an opioid, benzodiazepine and carisoprodol (Soma) will augment the ‘high’ from the opioids. The user may exhibit horizontal gaze nystagmus (HGN), average range pupil size, and decreased body temperature. To examine this combination further we must define the pharmacological effect of each drug.
 

Narcotic Analgesics reduce pain by activation of the mu receptors. This activation results in pupillary constriction and an increase in drug-seeking behavior. Benzodiazepine (benzo) drugs modulate the effects of GABA, produce sedation and reduce neuronal activity. They are CNS depressants and will cause HGN but do not affect pupil size. Carisoprodol (Soma) also functions as a CNS depressant and has been shown to potentiate GABA activation. Carisoprodol, a muscle relaxer, will usually cause pupillary dilation (exception (1) on Drug Symptomology Matrix).

The combination of these three types of drugs has for years been referred to as the "holy trinity". The synergistic effect on the user is powerful and can be deadly. Recently this combination has taken a new course with the abuse of Gabapentin (Neurontin) taking the place of carisoprodol. The pharmacological mechanism of gabapentin on the GABA receptors is unknown but was originally developed as a muscle relaxer. It is known that gabapentin, a CNS depressant, passes the blood-brain barrier and acts on neurotransmitters although it doesn’t bind to GABA receptors. The maximum daily recommended dose of gabapentin is 3600/mg and is being abused in amounts greater than 7200/mg.

Remember, effective communication during a roadside interview, or DRE evaluation, is critical in understanding the pharmacology of poly-category drug calls. It is also important to note that gabapentin is being abused with alcohol and will produce signs and symptoms not consistent with the BAC.

References

The Pharmacology and Toxicology of the ‘Holy Trinity’ - Horsfall - 2017 - Basic & Clinical Pharmacology & Toxicology - Wiley Online Library. (n.d.). Retrieved from https://onlinelibrary.wiley.com/doi/epdf/10.1111/bcpt.12655

Gabapentin (Neurontin) - StatPearls - NCBI Bookshelf. (2018, March 16). Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK493228/

Pfizer. (2011). Neurontin® (gabapentin) Capsules Neurontin® (gabapentin) Tablets Neurontin® (gabapentin) Oral Solution (2911805). Retrieved from Pfizer website: https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/020235s036,020882s022,021129s022lbl.pdf
 

About the Author: Sgt. Sam Criswell, a member of the Ohio State Highway Patrol, is the State Coordinator Representative to the Technical Advisory Panel, the Ohio DRE Program State Coordinator as well as being a DRE Instructor/DRE.
Created Feb 15, 2023 @ 2:40 PM | Updated May 11, 2023 @ 6:40 PM