What are the effects of amphetamine?

From the Guidelines

Amphetamine is a central nervous system stimulant medication that should be used with caution due to its high potential for abuse and dependence, and its use should be supervised by a healthcare provider with regular monitoring for effectiveness and side effects. Amphetamine works by increasing the activity of neurotransmitters like dopamine and norepinephrine in the brain, which improves focus, attention, and wakefulness. Common prescription forms include Adderall (mixed amphetamine salts), Dexedrine (dextroamphetamine), and Vyvanse (lisdexamfetamine).

• Typical adult dosing for ADHD starts at 5-10mg once or twice daily, potentially increasing to 20-40mg daily based on response and tolerability, as suggested by 1.
• Side effects may include decreased appetite, insomnia, increased heart rate, elevated blood pressure, and in rare cases, more serious cardiovascular effects, as noted in 1.
• Amphetamine has been shown to be effective in treating narcolepsy, with improvements in excessive daytime sleepiness and cataplexy, as demonstrated in 1.
• However, the overall quality of evidence for amphetamine's effectiveness in treating narcolepsy is very low, and the medication has a high potential for abuse and dependence, as stated in 1.
• Patients should take the medication exactly as prescribed, avoid alcohol, and report any concerning symptoms promptly to their doctor, as advised in 1.
• Regular monitoring for effectiveness and side effects is crucial, and healthcare providers should be aware of the potential risks and benefits of amphetamine treatment, as discussed in 1.

From the FDA Drug Label

ADVERSE REACTIONS Cardiovascular: Palpitations, tachycardia, elevation of blood pressure. There have been isolated reports of cardiomyopathy associated with chronic amphetamine use. OVERDOSAGE ... Manifestations of acute overdosage with amphetamines include restlessness, tremor, hyperreflexia, rhabdomyolysis, rapid respiration, hyperpyrexia, confusion, assaultiveness, hallucinations, panic states.

Amphetamine use can lead to various adverse reactions and overdose symptoms, including:

• Cardiovascular effects: palpitations, tachycardia, elevation of blood pressure, and cardiomyopathy with chronic use 2
• Central nervous system effects: psychotic episodes, overstimulation, restlessness, dizziness, insomnia, euphoria, dyskinesia, dysphoria, tremor, headache 2
• Overdose symptoms: restlessness, tremor, hyperreflexia, rhabdomyolysis, rapid respiration, hyperpyrexia, confusion, assaultiveness, hallucinations, panic states 2

From the Research

Amphetamine Overview

• Amphetamine was discovered over 100 years ago and has transformed from a freely available drug to a highly restricted Controlled Drug with therapeutic applications restricted to attention deficit hyperactivity disorder (ADHD) and narcolepsy 3.
• The balance of benefit/risk is the key challenge for its clinical use due to its diverse pharmacological actions, which translate into therapeutic efficacy, adverse events, and liability for recreational abuse 3.

Therapeutic Applications

• Amphetamine is used to treat ADHD and narcolepsy, with standard recommended dosage being 5-60 mg daily 4.
• It is also used off-label by college students for memory enhancement, test-taking ability, and study marathons, highlighting its high potential for abuse 4.
• Psychostimulants, including amphetamine, have been shown to be effective in improving emotional dysregulation, oppositional and conduct symptoms, and treatment-resistant depression 5.

Pharmacology and Mechanism

• Amphetamine stimulates the release of norepinephrine, affecting both α- and β-adrenergic receptor sites, leading to vasoconstriction, increased heart rate, and skeletal muscle blood flow 4.
• The prodrug lisdexamfetamine delivers d-amphetamine through an unusual metabolic route, contributing to its pharmacology and sustained efficacy in treating ADHD 3.

Safety and Efficacy

• Clinical signs of amphetamine overdose include hyperactivity, hyperthermia, tachycardia, tachypnea, mydriasis, tremors, and seizures 4.
• Treatment for amphetamine overdose is directed at controlling life-threatening central nervous system and cardiovascular signs, with prognosis depending on the severity and duration of clinical signs at presentation 4.
• A randomized, blinded, non-inferiority trial compared modafinil and amphetamine-dextroamphetamine for idiopathic hypersomnia and narcolepsy type 2, finding that amphetamine-dextroamphetamine was noninferior on multiple secondary measures of disease severity and symptomatology 6.

New Developments

• The dextroamphetamine transdermal system (d-ATS) is a recently approved stimulant patch for the treatment of ADHD in adults and pediatric patients, offering flexibility in length of stimulant effect and an alternative for those who cannot or prefer not to take medication orally 7.