Concerta is one of the big name Methylphenidate stimulants used to treat ADHD. The main difference between Ritalin and Concerta is that Concerta is a timed-release formula that is designed to give out a steady supply of stimulant through-out the day. It was first introduced in 2000 and since become major seller with Johnson & Johnson reporting sales $0.9 billion. A rise of 20% over 2005.
The original patent for Concerta expired in 2004 but the FDA have not approved any generic substitute drugs yet. To extract as much money as possible from Concerta, Johnson & Johnson have taken out two other patents on Concerta relating to its slow release mechanism. This has resulted in legal action against Andrx who are trying to produce a generic version.
Concerta tablets come in four strengths containig 18, 27, 36, or
54 mg of methylphenidate. One tablet should be taken daily and the company claims it provides effective treatment for 12 hours. The tablet has an outer coating of methylphenidate that dissolves within an hour of swallowing providing an immediate dose.
Over the next few hours, liquid from the stomach seeps into the tablet through a semi-permeable coating causing a reaction that forces the medication out of the Concerta tablet through a tiny laser drilled hole in the tablet. After six hours the rate of release increases to counteract the diminishing effect of the initial outer coating. The FDA found that Concerta in the blood stream increases rapidly reaching an initial maximum at about 1 hour, followed by gradual ascending concentrations over the next 5 to 9 hours after which a gradual decrease begins. Average times to reach peak effect across all doses of Concerta occurs between 6 to 10 hours.
The biologically inert components of the Concerta tablet remain intact during gastrointestinal transit and are eliminated in the stool as a tablet shell along with insoluble core components. It is possible that Concerta tablets may be visible on abdominal x-rays under certain circumstances, especially when digital enhancing techniques are utilized. The methylphenidate is most passed out of the body in urine.
In patients, there were no difference in the performance of Concerta when administered after a high fat breakfast. There is no evidence of the effectiveness of Concerta being effected by the presence or absence of food.
Concerta approval by the FDA is based on four double blind, active and placebo controlled studies. Three of the studies were on a total of 416 children aged 6 to 12 and each study lasted only a few weeks. The effectiveness of Concerta was measured by the teachers assessing the children’s behaviour for inattention or overactivity. The result showed a statistically significant reduction in symptoms, about 30-40%. However the value of such subjective measures is debatable and it is only with access to the full data set from the studies can you get an accurate understanding of Concerta’s impact.
One trial on teenagers taking Concerta was run, involving 177 adolescents between 13 and 18. Over a four week trial, Concerta led to a reduced score on an ADHD rating scale compared to a placebo.
No trials were run using Concerta on adults or on its effectiveness when used for more than 4 week. The FDA recommend that doctors prescribing Concerta for extended period regularly be reassessed to ensure the drug remain effective and safe.
What Concerta actual does to alleviate ADHD symptoms is in unknown. Methylphenidate is thought to block the reuptake of norepinephrine and dopamine into the presynaptic neuron and increase the release of these monoamines into the extraneuronal space. But it has not been proven that this is linked to the changes of ADHD symptoms reported by uses of Concerta.
The contrainciations of Concerta are numerous. Particularly patients with marked anxiety, tension, agitation, glaucoma and tics may find their symptoms increase whilst on Concerta. Patients who are taking monoamine oxidase inhibitors (antidepressants) should discontinue their treatment and leave a 14 day gap before taking Concerta. Because of the indigestible nature of the tablet, Concerta should not be used by people with gastrointestinal problems. Adverse reaction to Concerta include insomnia, twitching, nervousness, emotional lability, abdominal pain, and anorexia.
In addition to the active ingredient, methylphenidate, Concerta contain also contains the following ingredients: butylated hydroxytoluene, carnauba wax, cellulose acetate, hypromellose, lactose, phosphoric acid, poloxamer, polyethylene glycol, polyethylene oxides, povidone, propylene glycol, sodium chloride, stearic acid, succinic acid,
synthetic iron oxides, titanium dioxide, and triacetin.