Mixed Amphetamine Salts

All stimulant class side effects apply identically to mixed amphetamine salts (covered in detail on the methylphenidate page): appetite suppression, insomnia, increased heart rate/blood pressure, headache, irritability/mood changes (rebound vs overmedication distinction), growth suppression in children, emotional blunting at excessive doses, rare stimulant-induced psychosis (approximately 0.1-0.2% in pediatric patients; evidence suggests amphetamine-based stimulants may carry a somewhat higher psychosis risk than methylphenidate, particularly in younger patients, though absolute risk remains low with both classes).

End-of-dose rebound irritability, emotional lability, and mood instability as mixed amphetamine salts IR wears off can be misdiagnosed as a mood disorder, particularly bipolar disorder. The distinguishing feature is temporal: symptoms occur only during medication wear-off and are absent during peak effect and medication-free periods (weekends, holidays). True bipolar mood episodes are not synchronized to stimulant pharmacokinetics. Before adding a mood stabilizer or diagnosing bipolar disorder in a child on stimulants, map the mood symptoms to the dosing schedule.

The l-amphetamine component (25%) has relatively more peripheral noradrenergic effects. Some patients report more awareness of cardiovascular effects (palpitations, sense of "being stimulated"), dry mouth, or peripheral tension compared to pure dextroamphetamine formulations. Whether this represents a clinically meaningful difference or reporting bias is debated.

High-dose vitamin C and other urinary acidifiers can shorten amphetamine duration by accelerating renal clearance. GI pH effects from acidic beverages are possible but less clinically significant than sustained urinary acidification from supplements. Ask about supplements when efficacy suddenly changes.

The 4-6 hour duration of IR mixed amphetamine salts produces a more distinct "wear-off" than longer-acting formulations. End-of-dose rebound (irritability, emotional lability, worsening symptoms) is common and is a pharmacokinetic phenomenon, not a sign of inadequate dosing. Strategies: timing optimization, switching to ER formulation, small overlapping IR doses to smooth transitions.

Common. Related to sympathomimetic effects on salivary glands. More frequently reported with amphetamines than with methylphenidate in many clinical settings.

Jaw clenching and teeth grinding reported by some patients, particularly at higher doses. Related to increased dopaminergic and noradrenergic activity. Can occur during sleep. Dental consequences with chronic occurrence.