AMPHETAMINES

 AMPHETAMINES

BRAND NAME:- ADDERALL,ADZEnys etc.. many brands available in India.

Amphetamine is a powerful stimulator of the central nervous system . The central actions of amphetamines are largely medicated by release of NA from adrenergic neurones in the brain. Indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD).

PHARMACODYNAMIC ACTION:- 

These are synthesis compounds having a Pharmacological profile similar to ephedrine;

it has been demonstrated that amphetamine augments the concentration of noradrenaline in the prefrontal cortex and dopamine in the striatum on a dose and time-dependent manner. The indistinct release of neurotransmitters which include adrenaline is known to produce cardiovascular side effects.

There are old reports of a cognitive enhancement related to the administration of amphetamine in which improvements in intelligence test scores were reported.

In ADHD, amphetamine has been largely showed to produce remarkable improvements in school performance, behavior, and demeanor.1 The effect was shown to be produced through both racemic forms and to this date, the use of racemic forms 3:1 (D:L) is very common.3 The therapeutic effect of amphetamine on serotonin does not seem to have a significant clinical effect on ADHD as observed on comparative studies with amphetamine and fenfluramine, a powerful serotonin releasing factor. However, the indirect effect on serotonin might have an effect on the depression and anxiety profile of ADHD.

Studies regarding the illicit use of amphetamine in which heavy consumers were studied proved the generation of a paranoid state which flagged this drug as a psychiatric danger compound.13 This observation was supported by the continuous reports of misuse in patients under depression .

MECHANISM OF ACTION:-

 It is important to consider that amphetamine has a very similar structure to the catecholamine neurotransmitters mainly on the presence of a long planar conformation, the presence of an aromatic ring and nitrogen in the aryl side chain. Amphetamine, as well as other catecholamines, is taken into presynaptic nerve terminals by the association with two sodium ions and one chloride ion. The complex of the amphetamine with the ions is actively transported by monoamine reuptake transporters. As amphetamine acts competitively with the endogenous monoamines, the greater the number of amphetamines the more internalized amphetamine will be found.

Once inside the presynaptic terminal, amphetamine displaces other monoamines to be stored by VMAT2 which produces the pumping of the neurotransmitters into the synapse by a process called retro-transport.This process of release of neurotransmitters is approximately fourfold more potent in the d-isomer for the release of dopamine.

The mechanism of action of amphetamine is complemented by the inhibition of the reuptake and of monoamine oxidase which acts synergistically to produce a significant increase the monoamine concentration. This activity is not done as an inhibitor per se but more as a competitive substrate and thus, amphetamine is known to be a weak dopamine reuptake inhibitor, moderate noradrenaline reuptake inhibitor and very weak serotonin reuptake inhibitor. From this specific action, the l-isomer is known to be significantly less potent.

Lastly, amphetamine is known to be an inhibitor of the mitochondrial-bound enzyme MAO which is the catalytic enzyme in charge of degrading all the excess of neurotransmitters. This mechanism of action is often overpassed as amphetamine is a weak MAO inhibitor but this mechanism cannot be dismissed .

USED:- Amphetamine is used to treat attention deficit hyperactivity disorder (ADHD).

Narcolepsy:- It helps keep people with narcolepsy awake.

obesity :-it is used to short term weight loss.

SIDE EFFECTS:-Amphetamine oral tablet doesn’t cause drowsiness, but it can cause other side effects like headache

upset stomach,trouble sleeping,decreased appetite,unpleasant taste in your mouth,nervousness,dizziness,sexual dysfunction,vomiting,itching,diarrhea or constipation,dry mouth,weight loss ,mood swings etc.

DOSE:-  5-15mg oral