Drugs Most Commonly Abused by Anesthesia Providers and Why

Substance abuse among anesthesia care providers (ACPs) is influenced by the unique pharmacokinetic and pharmacodynamic properties of the drugs frequently used in their practice. Drugs that rapidly reach high concentrations in the brain and have a quick onset of action are particularly attractive to abusers. Many of these medications, such as propofol, inhalational agents, ketamine, and benzodiazepines, are administered intravenously or inhaled, allowing them to affect the brain quickly, thereby possessing a high potential for abuse. Opioids, especially fentanyl and sufentanil, remain the single most commonly abused class among anesthesia providers; the agents reviewed below are the non-opioid drugs most often involved. This abuse is driven by a combination of the drugs' pharmacological properties, ease of access in clinical settings, and the psychological effects experienced upon use.

Propofol

Propofol (2,6-diisopropylphenol) is one of the most commonly abused drugs by anesthesia providers. Introduced into clinical practice in the late 1980s, propofol is favored for its rapid onset, short duration, and favorable recovery profile. However, these same characteristics make it highly susceptible to abuse. Propofol increases dopamine levels in the brain's reward centers, leading to feelings of euphoria, elation, and even sexual disinhibition. Its high lipid solubility allows it to rapidly accumulate in the brain, producing quick and pleasurable effects, appealing to those seeking relief from stress or emotional discomfort.

Studies have reported increasing cases of propofol misuse among anesthesia providers, especially in regions like Australia, New Zealand, and the United States. The short duration of action also allows abusers to use the drug without obvious impairment over extended periods. However, propofol abuse is associated with significant risks, including respiratory depression, aspiration pneumonitis, and sudden death from cardiorespiratory arrest. The potentially lethal outcomes highlight the need for strict regulations, such as enhanced pharmacy control and routine drug screenings, to prevent misuse among healthcare professionals.

Inhalational Agents

Inhalational anesthetics, such as nitrous oxide (N₂O), isoflurane, sevoflurane, halothane, and desflurane, have also been implicated in substance abuse among anesthesia providers. While recreational use of these agents was once thought to be rare, recent data indicate an increase in abuse, particularly involving nitrous oxide. These agents enhance inhibitory signaling (through receptors like GABA_A and glycine) and reduce excitatory neurotransmission (via receptors like nicotinic acetylcholine and NMDA), resulting in their anesthetic and occasionally euphoric effects. Nitrous oxide, in particular, is associated with psychedelic-like effects due to NMDA antagonism, contributing to its misuse.

Abuse of inhalational agents carries serious consequences, including impaired cognitive function, emotional disturbances, and even death. The mortality rate associated with volatile agent abuse is significant, with some surveys reporting rates as high as 26% among documented cases in anesthesiology residency programs. Long-term abuse can also result in neurotoxicity and functional deficits. To mitigate these risks, effective measures such as improved accounting and regulation of these agents by hospital pharmacies are essential.

Ketamine

Ketamine, a central nervous system NMDA receptor antagonist, is another drug with significant abuse potential. Initially introduced as an anesthetic in the 1970s, ketamine is valued for its effectiveness in inducing anesthesia, managing pain, and its relatively safe profile. However, its dissociative and hallucinogenic effects make it a target for abuse. Ketamine can cause hallucinations, delusions, depersonalization, and cognitive disturbances, primarily through NMDA receptor antagonism and secondarily through its ability to inhibit norepinephrine, dopamine, and serotonin uptake and suppress cholinergic neuron activation in the prefrontal cortex.

While ketamine abuse is less often associated with immediate life-threatening effects compared to other anesthetic agents, it can cause significant cognitive and psychological dysfunction over time. Chronic use is linked to complications such as ulcerative cystitis, muscle cramps, cognitive impairment, and memory deficits. Imaging studies show that ketamine abusers may experience brain atrophy and degeneration, correlating with cognitive and behavioral dysfunction. The widespread use of ketamine in medical settings necessitates robust monitoring and preventive measures to limit access and reduce the risk of misuse.

Benzodiazepines

Benzodiazepines (BZDs), widely prescribed for anxiety and insomnia, are another common substance of abuse among anesthesia providers. These drugs, often initially used for therapeutic reasons, have significant potential for dependence and misuse. Benzodiazepines are particularly attractive to abusers due to their calming effects, but they also cause dose-dependent motor and cognitive impairment, memory loss, and attention dysfunction. Abuse may progress from legitimate use to involuntary dependence, especially when healthcare providers exceed recommended dosages or durations.

The potential for benzodiazepine misuse is concerning due to its effects on cognitive and motor function, which can significantly impair clinical performance. Benzodiazepine abuse among ACPs is often associated with the management of stress, anxiety, and insomnia, conditions exacerbated by the high-stress nature of their work environment. This underscores the importance of monitoring prescriptions and usage patterns among healthcare professionals to prevent abuse.