What is methylphenidate?
Methylphenidate is a psychostimulant that since the beginning of the sixties, has been registered as a medicinal product. The difference with amphetamine is that it contains a core-piperidine in place of a fenethylaminekern. It has a low bioavailability of 11 to 51%, depending on the individual recording. Methylphenidate is among others on the market under the brand names Concerta Janssen-Cilag, Equasym UCB Pharma, Medikinet of EuroCept and Ritalin, Belgium: Ritalin from Novartis. In the Netherlands issued for methylphenidate 178 000 prescriptions in the year 2000. In 2005, it was stipulated that number had risen to 350,000 and in 2010 it was 980 000 times.
Methylphenidate hydrochloride is better soluble in water and blood, salt, which is produced by the basic reaction of the NH group of methyl-2-phenyl-2- (2-piperidyl) acetate with hydrochloric acid.
Properties and application
Methylphenidate is a ketamine and inhibits the re-uptake of dopamine and noradrenaline.
In controlled trials in approximately 70% of adequately treated children and adolescents with ADHD showed a positive effect on their concentration, activity, impulsivity and aggressiveness.
Methylphenidate in the conventional tablet form work after half an hour and was developed after three to four hours. Controlled release dosage working eight to twelve hours. It is of great importance to take in the medicament at fixed times. First, to get routine, second, because not timely dose can cause undesirable fluctuations in the presence and absence of symptoms. The user may then think that the agent is not working. Because many patients by the nature of their condition have difficulty planning, it is advisable to purchase a watch or pill box with adjustable timer.
According to the working group guideline development-mental health 'will be preferred in practice usually given to long-acting methylphenidate. Arguments for this are greater adherence, reduced stigma, lower risk of abuse and more stable set.
Methylphenidate is for children and adolescents only registered in the Netherlands. For adults, it is registered for the indication narcolepsy. In adults with ADHD, the agent may need therefore, only be prescribed by the doctor off label, i.e., pre-treatment for which the agent has not been registered.
Methylphenidate side effects (Possible)
Possible side effects, which often diminish over time, are: palpitations, a hunted feeling, nausea, loss of appetite, more trouble on or sleep. In the longer term, sometimes weight loss or poor growth, and negatively affect the development of the (front) brains. At first it may appear mild euphoria subsides after a few weeks. Although the onset of depression is alerted when treated with methylphenidate, is about no consensus among scientists. In addition, depression is a very common disorder comorbid with ADHD, which makes distinction as to cause is not well possible. But there is also a relation with an increase in suicides among young people through the use of methylphenidate. After developing of the last dose evening can experience a rebound effect, particularly in the form of an increase of hyperactivity, agitation, irritability or reduction in concentration. The most common side effects of Ritalin include nervousness, irritability, dysphoria, sleep disturbances, headaches, tics, increase blood pressure and pulse, thyroid problems, weight loss and decreased appetite, feelings of unrest, skin problems, feelings of lethargy, urinary problems, growth disorders, itching.
Applications
Except as methylphenidate in ADHD medication is also prescribed for ADD and narcolepsy and some other diseases.
Use in applications where the product is not registered in off-label use, such as appetite suppressant or as a psychostimulant, is considered abuse. Methylphenidate is among other hard drugs included in List 1 of the Dutch Opium Act, and has the same international status. Therefore methylphenidate may officially not be carried without written statement from the prescribing physician about the border. Recreational use of methylphenidate (Ritalin) is punishable as a stimulant. Ethicists in Britain put here in 2009 questioned. The drug could be safely used by healthy adults to improve cognitive function.
Research has shown that reacts about 70-80% of children with ADHD positively to methylphenidate which attention deficit, hyperactivity and impulsivity are significantly less. It also found that people with ADD who are well established medication have less need for drug use / abuse, because the active ingredients to eliminate the effect of the drug. Young people who take methylphenidate or swallowed do not seem more likely than others to start using drugs, on the contrary, timely treatment of ADHD appears to reduce the risk of later addiction strongly.
Methylphenidate is available in the form of tablets with a short duration of action and as capsules with longer-term effect. The short-acting form is available under different brand names and in addition there are several generic versions on the market. In practice it has been found that there may be in operation between different brands slight differences, so that the dosage may need to be adjusted by a change of brand. This may vary individually.
Methylphenidate dosage
Characteristic of methylphenidate, which the substance is rapidly absorbed into the blood, works fast and is quickly broken down again. For the short-acting tablets, this means that one dose is quite fast and worked out a follow-dose should be taken strictly on time. The concentration in the blood exhibits differently to large fluctuations. If a dose is elaborated may be violating a 'rebound effect' on.
In a rebound the drug is suddenly developed and come to the ADHD symptoms returned to an increased extent. The behavior is then busier and more impulsive than before the medication. Rebound occurs not because the medication is not taken regularly enough. At the end of the day must be stopped the intake of methylphenidate because otherwise one night can not sleep. Stopping the methylphenidate (in the evening) can be tedious. If the rebound phenomena at the end of the day are too much, it can be decided for that reason to completely stop the medication, it normally takes a half hour or an hour, but if it is too long and too hard, the agent may get worse than the ailment. Because the drug dopamine uptake affecting dopamine, and under a variety of conditions, much or little used by the brains is, it is impossible to estimate in every how many hours it is necessary to take a tablet. Normally swallows one 10 mg in the morning and late in the morning, and then another 10 mg of the end of the afternoon 10 mg. Often in the morning is required than in the afternoon, a lower dose it can also halve the tablets or take only two tablets per day.
If one is doing strenuous things, like driving a car, one has perhaps more necessary because some activities require more dopamine. Therefore, it is a matter of "trial and error" (a number of ways to try, until the right one is found) and not at the time telling how much and when one takes the medication.
Because of the above problems have been developed with the sustained release capsules. They do not need to be administered less frequently, are more evenly absorbed into the body and there are no intermediate rebounds at regular ingestion (in which the symptoms for which the agent is swallowed return temporarily intensified). There is less chance of forgetting a subsequent dose. Because less is dosed at the wrong times, the operation is generally more uniform.
An unfavorable feature of methylphenidate is individually very widely differing bioavailability. This ranges from 11 to 51%. Especially in the beginning, it is therefore difficult to determine what is the right dose. There could easily arise under or overdosing. It is quite possible that is sometimes mistakenly thought that the drug is not working properly, when in fact it is because of an incorrect dosage.
It is known that the ingestion of methylphenidate together with orange juice (high in vitamin C) brings about a reduction of the operation. This is because vitamin C can inhibit the absorption of methylphenidate in the intestines. At a high vitamin C used is, therefore, a higher dosage of the drug is necessary. With tea intake also has this effect, presumably by the binding of the medicament to the tannins (tannic acid) in the tea.
Forms of methylphenidate
Short-acting tablets
Drugs that immediately after taking methylphenidate in the body release are among a number of brand names such as Ritalin, Ritalin or Rubio. They all contain the same active substance. These funds should be taken often more than once per day. This means the user or his attendants there to think that the medicine is taken on time. This can lead to reduced patient compliance and hence to a less effective treatment. At each individual working methylphenidate different. It is important that the correct time interval, and dose is found in the inregelingsperiode of the drugs.
Dosage forms with slow release
Dosage forms with slow release of the active substance methylphenidate have a longer duration of action than tablets, therefore they need to be administered less frequently. They are marketed under the brand names Ritalin MR, Concerta, and Equasym Medikinet. Run time will vary slightly by brand. The delivery can also be affected by concomitant food ingested. In practice, the duration of action also appears to vary significantly for each individual. Also varies by brand ratio immediately issued and regulated released methylphenidate and also varies the way in which this regulation. As a result, long-acting preparations with similar dose not interchangeable.
Slow release methylphenidate is reimbursed via the basic insurance in the Netherlands, but has through the GVS a high contribution. The was given by the examining body reason that this form would not offer added therapeutic value in relation to the short-acting form. An exception is Methylphenidate Retard Rainbow Pharmacy. This preparation is still covered by most insurers indeed the basic insurance. Insurer Achmea found the declarations of the Rainbow pharmacy however erroneous and got from the judge right. She did the Rainbow pharmacies in 2014 not to offer new contract relating to the Health Insurance Act.
In the past there have been vain of litigation for all formulations with slow release via the basic insurance to be reimbursed in full.