Structural Biochemistry/Ritalin

Introduction

Ritalin, also known as methylphenidate, is a psychostimulant drug that works on the central nervous system. It has been typically prescribed to treat ADHD (or Attention Deficit Hyperactivity Disorder) and narcoleptic patients since 1960; However, it got widely spread in the 1990's when ADHD became more widely accepted. Methylphenidate is a white, odorless, fine crystalline powder which is acidic. Ritalin is freely soluble in water and methanol, soluble in alcohol, and slightly soluble in chloroform and acetone.

File:Methylphenidate-.png

Chemical Structure

History

Methylphenidate was first synthesized in 1944, and was identified as a stimulant in 1954. Methylphenidate was synthesized by Ciba (now Novartis) chemist Leandro Panizzon. His wife, Marguerite, had low blood pressure and would take the drug as a stimulant before playing tennis. He named the substance Ritaline, after his wife's nickname, Rita. Originally it was marketed as a mixture of two racemates, 80% (±)-erythro and 20% (±)-threo. Subsequent studies of the racemates showed that the central stimulant activity is associated with the threo racemate and were focused on the separation and interconversion of the erythro isomer into the more active threo isomer. Beginning in the 1960s, it was used to treat children with ADHD or ADD, known at the time as hyperactivity or minimal brain dysfunction (MBD). Production and prescription of methylphenidate rose significantly in the 1990s, especially in the United States, as the ADHD diagnosis came to be better understood and more generally accepted within the medical and mental health communities. In 2000 Janssen received U.S. Food and Drug Administration (FDA) approval to market "Concerta". See the "Extended-release" section of this article, below, for more information about Concerta.

Side Effects

Methylphenidate has side effects; if these side effects are severe or do not go away, it is essential to contact a doctor:

Nervousness
Difficulty falling asleep or staying asleep
Dizziness
Vomiting
Loss of appetite
Stomach pain
Diarrhea
Nausea
Heartburn
Dry mouth
Headache
Muscle tightness
Uncontrollable movement of a part of the body
Restlessness
Numbness, burning or tingling in extremities
Decreased sexual desire
Painful menstruation

Taking Ritalin

Ritalin comes in different forms including: immediate-release tablets, chewable tablets, liquids, extended-release tablets, extended release capsules, and extended-release tablets.

All forms of methylphenidate are taken orally. Adults typically take the medication three times a day, while children take it twice a day, typically before meals. To avoid the side effects of being unable to sleep, patients should not take their last dosage after 6PM.

References

http://www.rxlist.com/ritalin-drug.htm

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000606/

http://psychopharmacopeia.com/index.php?generic=methylphenidate