Management of overdoses of loperamide, gabapentin, and modafinil: a literature review

The Issue of "Smart Drugs" on the Example of Modafinil: Toxicological Analysis of Evidences and Biological Samples

Cognitive enhancement through stimulants such as modafinil is becoming increasingly popular, with many individuals using prescription stimulants for non-medical purposes to improve alertness, attention, and mood. The misuse of such substances has raised concerns, particularly in forensic toxicology. The UHPLC-QqQ-MS/MS method was developed to quantify modafinil in evidentiary samples and biological materials. Additionally, the authors noted the presence of sodium adducts during the analysis of samples with high concentrations of modafinil. The method was validated for accuracy, precision, and linearity, with a concentration range of 0.1-10.0 µg/mL for the evidences and 1.0-100.0 ng/mL for blood. The method successfully detected modafinil as the sole substance in all evidences, with concentrations ranging from 90.7 to 120.8 mg, corresponding to 45.5% to 80.5% of the labeled dose. The method was applied to real post-mortem human cases, where, among others, the concentration of modafinil in blood was 110 ng/mL, whereas, in another case, the concentration of modafinil in the putrefaction fluid exceeded 1000 ng/mL. The developed UHPLC-QqQ-MS/MS method is effective for the quantification of modafinil in evidentiary samples and biological materials, offering a reliable tool for forensic toxicology applications. This method can be used to evaluate modafinil use in both legal and illicit contexts, including cases of overdose or misuse.

State-level response to gabapentin misuse in the United States: Implications and future direction

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

Gabapentin misuse is on the rise and has forced many US states to mobilize policies to address this public health concern. The purpose of this manuscript is to update state-level gabapentin misuse-related policies in the US through September 1, 2021, discuss the benefits and risks of current measures, and highlight gaps in national response.

METHODS

Identification of state and federal district policy changes and deliberations related to gabapentin were searched via internet for all 50 states and 1 federal district (n = 51). Only results from state regulatory bodies, such as the board of pharmacy, or state legislative bodies, such as the senate, were considered for inclusion.

RESULTS

Results showed that 22 states and federal districts (43.1%) tightened regulation, while another 2 (3.9%) are considering doing so. Of the 22 states and federal districts with policy changes, 15 (68.2%) enrolled gabapentin into their prescription drug monitoring program, while 7 (31.8%) reclassified gabapentin as a Schedule V controlled substance (C-V).

CONCLUSION

Absent of federal guidance surrounding gabapentin misuse, the onus has fallen on individual states; thus, approaches have ranged from no intervention to reclassification as a C-V. These measures aim to reduce medication supply but fall short of addressing patient outcomes and reducing harm. Therefore, harm reduction-informed public health policies must be implemented to positively impact patient outcomes and enhance safety.

Extracorporeal Treatment for Gabapentin and Pregabalin Poisoning: Systematic Review and Recommendations From the EXTRIP Workgroup

Toxicity from gabapentin and pregabalin overdose is commonly encountered. Treatment is supportive, and the use of extracorporeal treatments (ECTRs) is controversial. The EXTRIP workgroup conducted systematic reviews of the literature and summarized findings following published methods. Thirty-three articles (30 patient reports and 3 pharmacokinetic studies) met the inclusion criteria. High gabapentinoid extracorporeal clearance (>150mL/min) and short elimination half-life (<5 hours) were reported with hemodialysis. The workgroup assessed gabapentin and pregabalin as "dialyzable" for patients with decreased kidney function (quality of the evidence grade as A and B, respectively). Limited clinical data were available (24 patients with gabapentin toxicity and 7 with pregabalin toxicity received ECTR). Severe toxicity, mortality, and sequelae were rare in cases receiving ECTR and in historical controls receiving standard care alone. No clear clinical benefit from ECTR could be identified although major knowledge gaps were acknowledged, as well as costs and harms of ECTR. The EXTRIP workgroup suggests against performing ECTR in addition to standard care rather than standard care alone (weak recommendation, very low quality of evidence) for gabapentinoid poisoning in patients with normal kidney function. If decreased kidney function and coma requiring mechanical ventilation are present, the workgroup suggests performing ECTR in addition to standard care (weak recommendation, very low quality of evidence).

Gabapentinoid Pharmacology in the Context of Emerging Misuse Liability

This article will review the epidemiology and pharmacology of gabapentinoids (gabapentin and pregabalin) relevant to their emerging misuse potential and provide guidance for clinical and regulatory management. Gabapentinoids are γ-aminobutyric acid analogues that produce their therapeutic effects by inhibiting voltage-gated calcium channels and decreasing neurotransmitter release. Recently gabapentinoid prescribing and use have increased tremendously. Although traditionally thought to possess a favorable safety profile, gabapentinoid misuse has also risen significantly. Gabapentinoid misuse generally occurs in combination with other substances, most notably opioids, and may be for purposes of eliciting euphoric effects, enhancing the effects of other substances, or self-treating conditions such as withdrawal, pain, anxiety, or insomnia. Given its faster onset, increased bioavailability and potency, and nonsaturable absorption, pregabalin's pharmacokinetics theoretically enhance its misuse liability versus gabapentin. However, gabapentin can produce similar euphoric effects, and epidemiologic studies have identified higher rates of gabapentin misuse in the United States, likely because of greater availability and less regulated prescribing. Although adverse events of gabapentinoid-only ingestion are relatively benign, a growing body of evidence indicates that gabapentinoids significantly increase opioid-related morbidity and mortality when used concomitantly. In addition, significant withdrawal effects may occur on abrupt discontinuation. As a result of these trends, several US states have begun to further regulate gabapentinoid prescribing, reclassifying it as a controlled substance or mandating reporting to local prescription drug-monitoring programs. Although increased regulation of gabapentin prescribing may be warranted, harm reduction efforts and increased patient and provider education are necessary to mitigate this concerning gabapentinoid misuse trend.

Hyponatraemia and cerebral oedema due to a modafinil overdose

Modafinil is a non-amphetamine stimulant that is prescribed for narcolepsy-associated sleepiness as well as reported off-licence uses among university students looking to improve wakefulness and focus. There is limited information in the medical literature about supratherapeutic modafinil dosage, symptomatology and management of overdose. We report a case of a healthy 32-year-old man who was found unconscious, having vomited, with an empty modafinil blister strip. At the emergency department, he presented with reduced Glasgow Coma Scale and prolonged episodes of vomiting. This acute presentation was conservatively managed in the intensive care unit. Antibiotics were also given for a suspected aspiration pneumonia. CT of the head showed cerebral oedema and biochemistry investigations revealed hyponatraemia. Result aetiology was unclear, however, it has been theorised to be secondary to a sizeable modafinil overdose.