Amphetamine, Dexamphetamine, Lisdexamfetamine & ...

Don't stop here!

Get access to 133 more Pharmacology lessons & 13 more medical school learning courses with one subscription!

Try 7 days free

FAQs

What is the mechanism of action of amphetamine, dexamphetamine, lisdexamfetamine, and methylphenidate?

Amphetamine and dexamphetamine promote the release of monoamines, specifically dopamine and norepinephrine, into the synaptic cleft. This is facilitated by their roles as full agonists of the trace amine-associated receptor 1 (TAAR1) and by inhibiting the vesicular monoamine transporter 2 (VMAT2). Lisdexamfetamine, a prodrug of dexamphetamine, has a more gradual onset and prolonged duration of action, which decreases its potential for abuse. Methylphenidate, on the other hand, hampers the function of monoamine transporters, especially dopamine (DAT) and norepinephrine transporters (NAT), causing an upsurge of these neurotransmitters in the synaptic cleft.

What are some of the primary indications for psychostimulant medications such as amphetamines and methylphenidate?

The primary therapeutic use of these medications is for the management of attention-deficit/hyperactivity disorder (ADHD). Additionally, they can be prescribed to treat moderate to severe binge eating disorders. Methylphenidate, in particular, is also recognized for its efficacy in addressing narcolepsy.

What are some contraindications and precautions that should be considered when prescribing psychostimulants?

These medications should not be administered to individuals who are currently on MAO inhibitors or have discontinued their use within the past 14 days due to the heightened risk of sympathetic overactivation. Furthermore, they are not recommended for individuals with hyperthyroidism or pheochromocytoma due to analogous risks. Careful consideration should be given when prescribing these medications to patients with a documented history of substance abuse or those diagnosed with psychiatric or cardiovascular conditions.

What side effects are commonly associated with the use of prescribing psychostimulants?

Users of these medications may experience side effects such as insomnia, weight loss, nausea, and headaches. To mitigate the risk of insomnia, it's advisable to avoid consumption of these medications in the early afternoon or evening. Periodic monitoring of weight, cardiovascular activity, and height may be warranted.

Why is lisdexamfetamine associated with a lower risk of abuse compared to other amphetamine derivates?

Lisdexamfetamine is classified as a prodrug, implying that it remains inactive until metabolized within the body. This metabolic conversion leads to a gradual onset and sustained release of the active compound. Consequently, there's a moderated spike in dopamine levels, which reduces the euphoric sensation often linked with drug misuse. This characteristic results in a diminished potential for abuse and diversion in comparison to immediate-release counterparts.