Amphetamine exerts its behavioral effects by altering the use of monoamines as neuronal signals in the brain, primarily in catecholamine neurons in the reward and executive function pathways of the brain. Amphetamine may also decrease the effects of antihypertensives and antipsychotics due to its effects on blood pressure and dopamine respectively. In particular, amphetamine may decrease the effects of sedatives and depressants and increase the effects of stimulants and antidepressants. Amphetamine also interacts with MAOIs, particularly monoamine oxidase A inhibitors, since both MAOIs and amphetamine increase plasma catecholamines (i.e., norepinephrine and dopamine); therefore, concurrent use of both is dangerous. Inhibitors of enzymes that metabolize amphetamine (e.g., CYP2D6 and FMO3) will prolong its elimination half-life, meaning that its effects will last longer. Many types of substances are known to interact with amphetamine, resulting in altered drug action or metabolism of amphetamine, the interacting substance, or both.
The Cochrane reviewsnote 7 on the treatment of ADHD in children, adolescents, and adults with pharmaceutical amphetamines stated that short-term studies have demonstrated that these drugs decrease the severity of symptoms, but they have higher discontinuation rates than non-stimulant medications due to their adverse side effects. Zinc supplementation may reduce the minimum effective dose of amphetamine when it is used for the treatment of ADHD.note 17 Norepinephrine reuptake inhibitors (NRIs) like atomoxetine prevent norepinephrine release induced by amphetamines and have been found to reduce the stimulant, euphoriant, and sympathomimetic effects of dextroamphetamine in humans. Long-term amphetamine exposure at sufficiently high doses in some animal species is known to produce abnormal dopamine system development or nerve damage, but, in humans with ADHD, long-term use of pharmaceutical amphetamines at therapeutic doses appears to improve brain development and nerve growth. Because of its behavior as a prodrug and its pharmacokinetic differences, lisdexamfetamine has a longer duration of therapeutic effect than immediate-release dextroamphetamine and shows reduced misuse potential.
Call your doctor for medical advice about side effects. Some side effects may occur that usually do not need medical attention. Although not all of these side effects may occur, if they do occur they may need medical attention.
Notes
In contrast, levoamphetamine may have a greater effect on cataplexy, a symptom more sensitive to the effects of norepinephrine and serotonin. In addition, both a review and a meta-analytic systematic review found lisdexamfetamine to be superior to placebo in several secondary outcome measures, including persistent binge eating cessation, reduction of obsessive-compulsive related binge eating symptoms, reduction of body-weight, and reduction of triglycerides. This view is supported by the failure of anti-obesity medications and other appetite suppressants to significantly reduce BED symptom severity, despite their capacity to induce weight loss. While lisdexamfetamine’s anorexigenic effects contribute to its efficacy in BED, evidence indicates that the enhancement of cognitive control is necessary and sufficient for addressing the disorder’s underlying psychopathology.
- Symptoms of a moderate and extremely large overdose are listed below; fatal amphetamine poisoning usually also involves convulsions and coma.
- Do not sell, give away, or let anyone else take your medication.
- In particular, aerobic exercise decreases psychostimulant self-administration, reduces the reinstatement (i.e., relapse) of drug-seeking, and induces increased dopamine receptor D2 (DRD2) density in the striatum.
- A large number of alternative synthetic routes to amphetamine have been developed based on classic organic reactions.
- Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.
Similar to most biomolecules and other orally administered xenobiotics (i.e., drugs), amphetamine is predicted to undergo promiscuous metabolism by human gastrointestinal microbiota (primarily bacteria) prior to absorption into the blood stream. Following absorption into the blood stream, lisdexamfetamine is completely converted by red blood cells to dextroamphetamine and the amino acid L-lysine by hydrolysis via undetermined aminopeptidase enzymes. The immediate-release and extended release variants of salts of both isomers reach peak plasma concentrations at 3 hours and 7 hours post-dose respectively. Although preliminary observational evidence suggests potential benefit from adjusting amphetamine doses according to menstrual cycle phases, randomized controlled trials have not evaluated this practice. In December 2017, the first study assessing the interaction between amphetamine and human carbonic anhydrase enzymes was published; of the eleven carbonic anhydrase enzymes it examined, it found that amphetamine potently activates seven, four of which are highly expressed in the human brain, with low nanomolar through low micromolar activating effects. Acute amphetamine administration in humans increases endogenous opioid release in several brain structures in the reward system.
Your doctor may order certain tests to check your body’s response to amphetamine and your blood pressure. Do not flush this medication down the toilet. Place the medication in a safe location – one that is up and away and out of their sight and reach.
Amphetamines
Amphetamine is a mix of dextroamphetamine and levoamphetamine. Many amphetamines treat multiple conditions. One amphetamine that doesn’t see any prescription use — but does see widespread Amphetamine Drug Profile nonmedical use — is MDMA.
What are amphetamines?
The dose of this medicine will be different for different patients. If you are using the extended-release oral disintegrating tablet, make sure your hands are dry before you handle the tablet. Measure the extended-release oral suspension with a marked measuring spoon, oral syringe, or medicine cup. If you feel that the medicine is not working properly after using it for several weeks, check with your doctor first and do not increase the dose. The presence of other medical problems may affect the use of this medicine. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Calls to numbers marked with (I) symbols will be answered or returned by one of the treatment providers listed in our Terms and Conditions, each of which is a paid advertiser.
- However, high amphetamine doses that are above the therapeutic range can interfere with working memory and other aspects of cognitive control.
- As a member of the phenethylamine class, amphetamine is also chemically related to the naturally occurring trace amine neuromodulators, specifically phenethylamine and N-methylphenethylamine, both of which are produced within the human body.
- Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur.
- The pathophysiology of BED is not fully understood, but it is believed to involve dysfunctional dopaminergic reward circuitry along the cortico-striatal-thalamic-cortical loop.
Prescription amphetamines
Once a tolerance to amphetamines has built up, users will feel the need to take the drug constantly to feel normal levels of happiness. This artificial production of dopamine is highly addictive and causes many to become hooked on abusing amphetamines. Depending on whether a person is abusing amphetamines in pill, powder, crystal, or liquid forms will dictate how they take the drug. Most forms of prescription amphetamines come in the form of pills or tablets but will occasionally be administered orally as a liquid.
Keep all medication out of sight and reach of children as many containers are not child-resistant. Store the orally disintegrating tablet blister packages in the provided plastic sleeves. Keep this medication in the container it came in, tightly closed, and out of reach of children.
Dopamine
You may move the tablet around between the tongue and the roof of the mouth until it melts. Remove Adzenys XR-ODT® from the blister pack by peeling back the foil, then taking the tablet out. Do not open the blister pack that contains the tablet until you are ready to take it. You may divide the Dyanavel® XR 5-mg tablet into equal parts at the score line. You may chew or swallow the Dyanavel® XR tablet whole.
Amphetamine prescription shortages
Amphetamine exerts analogous, yet less pronounced, effects on serotonin as on dopamine and norepinephrine. In other words, amphetamine induces competitive NET reuptake inhibition, non-competitive reuptake inhibition and efflux at phosphorylated NET via PKC activation, CAMKIIα-mediated NET efflux without internalization, and norepinephrine release from VMAT2. Subsequently, the cytosolic dopamine molecules are released from the presynaptic neuron into the synaptic cleft via reverse transport at DAT. Upon entering the presynaptic neuron, amphetamine provokes the release of Ca²⁺ from endoplasmic reticulum stores, an effect that raises intracellular calcium to levels sufficient for downstream kinase-dependent signalling. Amphetamine also inhibits monoamine oxidases at very high doses, resulting in less monoamine and trace amine metabolism and consequently higher concentrations of synaptic monoamines. When amphetamine accumulates in the presynaptic terminal, it collapses the vesicular pH gradient and releases vesicular monoamines into the neuronal cytosol.
Detection in body fluids
As with other CNS stimulants, mixing amphetamines and other substances can lead to serious side effects and fatal overdose. These medications are available in various forms, including tablets, capsules, orally disintegrating tablets, and oral liquid solutions, and can be immediate-release or extended-release. While amphetamines are normally prescribed, there are illegal variants (as well as abused prescription medications) that are sold on the street for the purpose of abuse. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
Illegal amphetamines
Nonmedical amphetamine use is common with amphetamine, dextroamphetamine and methamphetamine. There are several prescription amphetamine drugs, and even more brand names. Some countries, such as South Korea and Japan, have banned substituted amphetamines even for medical use.
Amphetamine is a weak base with a pKa of 9.9; consequently, when the pH is basic, more of the drug is in its lipid soluble free base form, and more is absorbed through the lipid-rich cell membranes of the gut epithelium. The oral bioavailability of amphetamine varies with gastrointestinal pH; it is well absorbed from the gut, and bioavailability is typically 90%. Acute amphetamine administration can also increase adrenocorticotropic hormone and corticosteroid levels in blood plasma by stimulating the hypothalamic–pituitary–adrenal axis. Amphetamine also induces the selective release of histamine from mast cells and efflux from histaminergic neurons through VMAT2.
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