Dexmethylphenidate: characteristics and side effects

This drug is used in the pharmacological treatment of ADHD.

Dexmethylphenidate is an isomer of methylphenidate, a drug used to treat children with ADHD.a medication used to treat children with ADHD. This variant of the well-known stimulant drug seems to work better than the original and its use seems to be spreading.

In this article we explain what dexmethylphenidate is and what effects it has, what its mechanism of action is, what adverse effects and interactions to be aware of, and what role it plays in addiction and dependence.

What is dexmethylphenidate and what are its effects?

Dexmethylphenidate or d-threo-methylphenidate is an isomeric variant of methylphenidate, a drug commonly used in people suffering from attention deficit hyperactivity disorder (ADHD). (ADHD).

There are two isomers of methylphenidate: d-threo-methylphenidate and l-threo-methylphenidate, two compounds that differ from the original molecule by small adjustments in the molecular chemical structure, which results in some properties of the drug being different. Apparently, only d-threo-methylphenidate would be the clinically active ingredient.

In Spain, the variant of methylphenidate that is marketed is the mixture of the two isomers, the racemic mixture (d,l)-threo-methylphenidate. In other countries, however, the variant dexmethylphenidate is already being used, which would provide exclusively the psychostimulant effects of methylphenidate. would exclusively provide the therapeutic psychostimulant effects, avoiding the undesiredThis variant of methylphenidate, however, is already being used in other countries and would provide exclusively therapeutic psychostimulant effects, avoiding cardiovascular and anorectic (appetite suppressant) side effects and reducing the abuse potential of the substance.

This variant of methylphenidate is marketed under the name Focalin and, like its analog, is used to treat individuals with adhd (age 5 years and older). Normally, if no benefit is observed after 4 weeks of use, it is usually discontinued.

The effects of dexmethylphenidate last between 4 to 6 hours (with the exception of the long-acting formulation, which lasts up to 12 hours).

Mechanism of Action

Although the mechanism of action of dexmethylphenidate has not been fully elucidated, it is suggested that it exerts its effect by amplifying the dopaminergic signal by blocking its reuptake at the presynaptic level.

This drug would also be able to block the reuptake of another neurotransmitter, noradrenaline, by binding to its specific transporter.by binding to its specific transporter. The overall effect is an increase in the attentional and alertness level of the subject. This can be measured with devices that pick up low voltage waves.

On the other hand, dexmethylphenidate increases the excitatory mechanisms of the brain, improving concentration, motor coordination and impulse control in the subject. In patients with ADHD, the effects of dexmethylphenidate are attributed to the ability of this drug to improve the inhibitory mechanisms of the frontosubcortical circuits in which dopamine is involved.

The compound would exert a regulatory action on the frontal cortex and subcortical structures, such as the ventral part of the ventral nucleus of the frontal nucleus.such as the ventral part of the striatal nucleus, in the basal ganglia. In this brain area there is also the nucleus accumbens, a structure in which dopamine would act by limiting the processing of the information to be processed, with the consequent improvement in the focus of the subject's attention.

Side effects

In general, although a drug such as dexmethylphenidate is fairly well tolerated, side effects may be observed at the start of treatment. side effects can be observed at the beginning of treatment (as with classical methylphenidate) (as is the case with classical methylphenidate), although they are usually transient. Occasionally, delaying or decreasing the ingested dose may be sufficient to reduce adverse reactions.

The patient may experience abdominal pain, changes in blood pressure and heart rate, and even nervous tics. (the risk in this respect is minimal). However, studies indicate that the side effects are mild and limited.

Some studies had postulated a possible link between the consumption of methylphenidate and a suppression in the secretion of growth hormone and prolactin. However, this relationship has now been dismissed, since child patients treated with the drug would regain their normal height in adolescence.

However, the consumption of dexmethylphenidate can cause a series of side effects that should be noted:

• Nervousness and anxiety
• Irritability
• Headache
• Stomach discomfort
• Difficulties in falling asleep
• Dizziness
• Nausea and vomiting
• Loss of appetite
• Weight loss

Interactions with other medications

People who are being treated with dexmethylphenidate should be aware of possible interactions with other medications. It is very important to always follow the guidelines given to you by your health care professional. your health care professional.

Next, we will see some of the drugs that are contraindicated in case of being in treatment with dexmethylphenidate:

• Isocarboxazid
• Iobenguan
• Linezolid
• Phenelzine
• Procarbazine
• Rasagiline
• Safinamide
• Selegiline (and transdermal selegiline)
• Tranylcypromine

Addiction and dependence

Methylphenidate is a stimulant drug with a certain power of addiction and dependence, similar to that of amphetamine.. For this reason, the consumption of this type of substances can generate dependence, both physical and psychological, more likely when dexmethylphenidate is used in high doses or as a recreational drug.

When used above the medical dosage range, stimulants can trigger psychosis processes, especially in predisposed individuals.especially in predisposed individuals. With the consumption of almost all drugs with addictive potential, a protein called FosB is activated, which is part of the brain reward circuit (in the nucleus accumbens).

This protein combines with other proteins and binds to receptors that promote the expression of certain neuronal genes which, in turn, modify the expression and activity of other neuronal groups, which can generate epigenetic changes (gene expression is altered by the addition of certain molecules to the DNA).

In several studies, dexmethylphenidate has shown benefits as a replacement therapy for people with methamphetamine addiction and dependence.. In addition, methylphenidate and amphetamines have also been investigated as a chemical replacement for treating people with cocaine addiction, in the same way that methadone is used as a replacement drug for physical heroin dependence.