Rebound hypersomnolence, stimulant abuse, and DAT-mediated dopamine release

Sedation After a Trial of Mixed Amphetamine Salts in a Boy with Attention-Deficit/Hyperactivity Disorder

BACKGROUND Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder that manifests in early childhood. Pharmacotherapy, including psychostimulants, is considered the cornerstone of ADHD management. Although stimulants have been associated with adverse effects, sedation following the administration of an amphetamine-based stimulant is an extremely rare adverse effect. CASE REPORT We report the case of a 6-year-old boy presenting with ADHD and a history of autism spectrum disorder (ASD). After discussing treatment options with his parents, he was started on a low dose of a methylphenidate medication. He was unable to tolerate the medication due to anorexia, insomnia, and irritability despite multiple adjustments in the dosages. A trial of immediate-release mixed amphetamine salts was initiated, starting from a low dose. The boy developed sedation and lethargy shortly after the administration of this medication. CONCLUSIONS Sedation is a rare adverse drug reaction to mixed amphetamine salts. Clinicians should proactively monitor for the possible adverse effects in patients with ASD and ADHD, including unexpected symptoms such as sedation. Reporting of adverse drug reactions should be encouraged to promote the post-marketing surveillance of medications.

Update on the pharmacologic management of narcolepsy: mechanisms of action and clinical implications

Narcolepsy is a chronic, debilitating neurological disorder of sleep-wake state instability. This instability underlies all narcolepsy symptoms, including excessive daytime sleepiness (EDS), symptoms of rapid eye movement (REM) sleep dysregulation (ie, cataplexy, hypnagogic/hypnopompic hallucinations, sleep paralysis), and disrupted nighttime sleep. Several neurotransmitter systems promote wakefulness, and various neural pathways are involved in regulating REM sleep-related muscle atonia, providing multiple targets for pharmacologic intervention to reduce EDS and cataplexy. Medications approved by the US Food and Drug Administration (FDA) for the treatment of EDS in narcolepsy include traditional stimulants (eg, amphetamines, methylphenidate), wake-promoting agents (eg, modafinil, armodafinil), and solriamfetol, which mainly act on dopaminergic and noradrenergic pathways. Sodium oxybate (thought to act via GABA_B receptors) is FDA-approved for the treatment of EDS and cataplexy. Pitolisant, a histamine 3 (H₃)-receptor antagonist/inverse agonist, is approved by the European Medicines Agency (EMA) for the treatment of narcolepsy with or without cataplexy in adults and by the FDA for the treatment of EDS in adults with narcolepsy. Pitolisant increases the synthesis and release of histamine in the brain and modulates the release of other neurotransmitters (eg, norepinephrine, dopamine). Antidepressants that inhibit reuptake of serotonin and/or norepinephrine are widely used off label to manage cataplexy. In many patients with narcolepsy, combination treatment with medications that act via different neural pathways is necessary for optimal symptom management. Mechanism of action, pharmacokinetics, and abuse potential are important considerations in treatment selection and subsequent medication adjustments to maximize efficacy and mitigate adverse effects in the treatment of patients with narcolepsy.