Acute dissection of the aorta with amphetamine misuse

Overdose of drugs for attention-deficit hyperactivity disorder: clinical presentation, mechanisms of toxicity, and management

The prevalence of attention-deficit hyperactivity disorder (ADHD) in the USA is estimated at approximately 4-9% in children and 4% in adults. It is estimated that prescriptions for ADHD medications are written for more than 2.7 million children per year. In 2010, US poison centers reported 17,000 human exposures to ADHD medications, with 80% occurring in children <19 years old and 20% in adults. The drugs used for the treatment of ADHD are diverse but can be roughly separated into two groups: the stimulants such as amphetamine, methylphenidate, and modafinil; and the non-stimulants such as atomoxetine, guanfacine, and clonidine. This review focuses on mechanisms of toxicity after overdose with ADHD medications, clinical effects from overdose, and management. Amphetamine, dextroamphetamine, and methylphenidate act as substrates for the cellular monoamine transporter, especially the dopamine transporter (DAT) and less so the norepinephrine (NET) and serotonin transporter. The mechanism of toxicity is primarily related to excessive extracellular dopamine, norepinephrine, and serotonin. The primary clinical syndrome involves prominent neurological and cardiovascular effects, but secondary complications can involve renal, muscle, pulmonary, and gastrointestinal (GI) effects. In overdose, the patient may present with mydriasis, tremor, agitation, hyperreflexia, combative behavior, confusion, hallucinations, delirium, anxiety, paranoia, movement disorders, and seizures. The management of amphetamine, dextroamphetamine, and methylphenidate overdose is largely supportive, with a focus on interruption of the sympathomimetic syndrome with judicious use of benzodiazepines. In cases where agitation, delirium, and movement disorders are unresponsive to benzodiazepines, second-line therapies include antipsychotics such as ziprasidone or haloperidol, central alpha-adrenoreceptor agonists such as dexmedetomidine, or propofol. Modafinil is not US FDA approved for treatment of ADHD; however, it has been shown to improve ADHD signs and symptoms and has been used as an off-label pharmaceutical for this diagnosis in both adults and children. The mechanism of action of modafinil is complex and not fully understood. It is known to cause an increase in extracellular concentrations of dopamine, norepinephrine, and serotonin in the neocortex. Overdose with modafinil is generally of moderate severity, with reported ingestions of doses up to 8 g. The most common neurological effects include increased anxiety, agitation, headache, dizziness, insomnia, tremors, and dystonia. The management of modafinil overdose is largely supportive, with a focus on sedation, and control of dyskinesias and blood pressure. Atomoxetine is a selective presynaptic norepinephrine transporter inhibitor. The clinical presentation after overdose with atomoxetine has generally been mild. The primary effects have been drowsiness, agitation, hyperactivity, GI upset, tremor, hyperreflexia, tachycardia hypertension, and seizure. The management of atomoxetine overdose is largely supportive, with a focus on sedation, and control of dyskinesias and seizures. Clonidine is a synthetic imidazole derivative with both central and peripheral alpha-adrenergic agonist actions. The primary clinical syndrome involves prominent neurological and cardiovascular effects, with the most commonly reported features of depressed sensorium, bradycardia, and hypotension. While clonidine is an anti-hypertensive medication, a paradoxical hypertension may occur early with overdose. The clinical syndrome after overdose of guanfacine may be mixed depending on central or peripheral alpha-adrenoreceptor effects. Initial clinical effects may be drowsiness, lethargy, dry mouth, and diaphoresis. Cardiovascular effects may depend on time post-ingestion and may present as hypotension or hypertension. The management of guanfacine overdose is largely supportive, with a focus on support of blood pressure. Overdose with ADHD medications can produce major morbidity, with many cases requiring intensive care medicine and prolonged hospital stays. However, fatalities are rare with appropriate care.

Aortic dissection in young adults who abuse amphetamines

BACKGROUND

Case reports suggest a relationship between amphetamine abuse/dependence and aortic dissection, but no population-based epidemiologic studies have examined this link. Our objective was to test the hypothesis that young adults with a diagnosis of amphetamine abuse/dependence would be at higher risk for aortic dissection after accounting for known risk factors.

METHODS

In this population-based case-control study of 30,922,098 discharges from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from 1995 to 2007, among persons aged 18 to 49 years, we identified 3,116 thoracic and thoracoabdominal aortic dissections using International Classification of Disease, Ninth Edition, Clinical Modification codes 441.01 and 441.03. The SURVEYLOGISTIC procedure in SAS 9.2 (SAS Institute, Cary, NC) was used to account for the Nationwide Inpatient Sample sampling methodology.

RESULTS

In a multiple logistic regression analysis, while controlling for known risk factors, amphetamine abuse/dependence was significantly associated with aortic dissection (adjusted odds ratio = 3.33, 95% CI = 2.37-4.69, P < .0001).

CONCLUSIONS

This statistically significant association suggests that amphetamine abuse/dependence may play a role in aortic dissection in young adults in the United States.

Aortic dissection after ingestion of "ecstasy" (MDMA)

The authors report a case of aortic dissection and cardiac tamponade in a 29-year-old man after ingestion of ecstasy (methylenedioxymethamphetamine, MDMA) at a "rave" party. There was no history of hypertension, myxoid heart disease, or other risk factors for aortic dissection in the deceased, although a minor degree of cystic medial necrosis was noted on histologic examination of the aorta. Autopsy toxicology revealed low residual levels of MDMA in the blood about 48 hours after ingestion of the drug. This case report describes a probable association between MDMA ingestion and aortic dissection in a previously well young adult. The likely mechanisms are discussed, and the difficulties in diagnosing this complication are highlighted.