Ritalin effects

Martin WR, Sloan JW, Sapira JD, et al Physiologic, subjective, and behavioral effects of amphetamine, methamphetamine, ephedrine, phenmetrazine, and methylphenidate in man. Clin Pharmacol Ther 12 245-258, 1971 McCormick TC Jr, McNeil TW Acute psychosis and Ritalin abuse. Tex State J Med... 

Methylphenidate (Ritalin, Concerta, Focalin). Methylphenidate was introduced in the late 1950s and is now the most widely used prescription stimulant. It was first used to treat ADHD in children but is also effective for narcolepsy. Like dextroamphetamine, methylphenidate should be started at 5 mg per dose given two to three times each day with meals. The average effective dose is 20-30 mg/day, but some patients require as much as 60 mg/day. The benefit of methylphenidate should also be apparent on the first day or so, and the dose can be increased every 5-7 days as needed. Focalin dosing is approximately half that of methylphenidate. 

Stimulants. Methylphenidate (Ritalin) and dextroamphetamine (Dexedrine) are the most widely used and perhaps the most effective medications when treating post-TBI apathy. They act by enhancing the activity of dopaminergic, noradrenergic and, to a certain extent, serotonergic brain systems. Stimulants act quickly to relieve the core symptoms of apathy, and they may also improve the impairments in attention and short-term memory that often follow TBl. Please refer to Chapter 8 for more information about the stimulants. 

Methylphenidate is a CNS stimulant similar to amphetamine however, in usual doses it has a more expressed action on mental activity rather than physical or motor activity. In therapeutic doses it does not raise blood pressure, respiratory rate, or increase heart rate. All of these effects as well as a number of others are associated with general excitement of the CNS. Tremor, tachycardia, hyperpyrexia, and a state of confusion can result from using large doses. It is used in treating moderate depression and apathetic conditions, and also as an adjuvant drug for treating attention deficit disorder in children.Synonyms of this dmg are meridil, ritalin, and others. 

Pentazocine (Talwin) (see also page 252) Street Names Crackers, poor man s h oin, T s and R s> Ts and Rits (all refer to combinations w/ Ritalin) (brands Talwin, Talwin Nx [CIV]) Use Medically used as opioid analgesic euphoria similar to heroin when mixed w/antihistamines combined w/ methylphenidate (Ritalin) is new abuse combination Actions Agonist-antagonist narcotic naloxone, a narcotic antagonist added to Talwin (Talwin NX) has reduced incidence of abuse Effects Euphoria, hallucinations, skin necrosis w/ illicit injection route... 

Racemic f/zreo-methylphenidate was approved for the treatment of fatigue, nausea, and depression in 1955 under the brand name Ritalin , and was first used in children in 1958 with an approval for hyperkinetic disorder (ADHD) in 1960. Methylphenidate has an even shorter half-life than amphetamine, and its use in treating ADHD was limited by the fact that schoolchildren would need to visit a nurse during the day to take a second dose of this scheduled drug (in order to maintain efficacy throughout the entire school day). In humans, injecting methylphenidate produces effects similar to intravenous cocaine, but oral methylphenidate is adsorbed very slowly from the gut into the blood and takes an unusually long time (estimated 2.5 h) to reach a peak concentration... 

Chan, Y.P., Swanson, J.M., Soldin, S.S., Thiessen, JJ-, and Macleod, S.M. (1983) Methylphenidate hydrochloride given with or before breakfast II. Effects on plasma concentration of methylphenidate and ritalinic acid. Pediatrics 72 56-59. 

Pelham, W.E., Sturges, J., and Hoza, J. (1989) The effects of sustained release 20 and 10 mg Ritalin bid on cognitive and social behavior in children with attention deficit disorder. Pediatrics 80 491-501. 

Methylphenidate and D-amphetamine are both short-acting compounds, with an onset of action within 30 to 60 minutes and a peak clinical effect seen usually between 1 and 2 hours after administration, lasting 2 to 5 hours. Therefore, multiple daily administrations are required for a consistent daytime response. The amphetamine compound Adderall, the sustained-release preparations of methylphenidate and dextroamphetamine, and pemoline are all intermediate-acting compounds with an onset of action within 60 minutes and a peak clinical effect seen usually between 1 and 3 hours after administration and maintained for up to 8 hours (8 hours with metadate C.D. and Ritalin LA 12 hours with Concerta), allowing for a single dose for the entire school day. Adderall XR is a 12 hour preparation. 

Bergman, A., Winters, L., and Cornblatt, B. (1991). Methylphenidate effects on sustained attention. In Greenhill, L. and Osman, B., eds. Ritalin Theory and Patient Management. New York Mary Ann Liebert, Inc., pp. 223-231. 

Barkley, R.A., Karlsson, J., Strzelecki, E., and Murphy, J.V. (1984) Effects of age and Ritalin dosage on the mother-child interactions of hyperactive children. / Consult Clin Psychol 52 750-758. 

Barkley RA, Karlsson J, Pollard S, et al. Developmental changes in the mother-child interactions of hyperactive boys effects of two dose levels of Ritalin. J Child Psychol Psychiatry 1985 26 705-715. 

Even when effective in controlling behavior, Ritalin and other stimulants have side effects common with use of amphetamines. These include nervousness, insomnia, and perhaps some more long-term problems such as dependency, slowed growth, or depression. Critics sometimes note the similarity between cocaine and the active chemical ingredient in Ritalin, methylphenidate. Both stimulate the dopamine system of the brain, but cocaine does so quickly and methylphenidate does so slowly. The similarities show in the abuse of Ritalin for its pleasure-inducing qualities. 

Figure 25-8 Baseline separation of enantiomers of the drug Ritalin by HPLC with a chiral stationary phase. One enantiomer is pharmacologically active for treating attention deficit disorder and narcolepsy. The other enantiomer has little activity but could contribute to undesired side effects. Pharmaceutical companies are moving toward providing enantiomerically pure drugs, which could be safer than mixtures of optical isomers. [From R. Bakhtiar, L Ramos, and F. L. S. Tse, "Quantification of Methylphenidate in Plasma Using Chiral Uquid-Chromatography/Tandem Mass Spectrometry Application to Taxicokinetic Studies," Anal. Chim. Acta 2002, 469.261.]...

The utility of this model was further evaluated by establishing the procognitive effects of established attention deficit hyperactivity disorder (ADHD) agents in the juvenile rat pups.82-83 Methylphenidate (Ritalin ) was tested in the juvenile pup model to assess its effects on acquisition in the PAR. Methylphenidate (3 mg/kg, ip) was chosen as an intermediate dose, which in adult rats provided dear evidence of psychostimulant activity. Pretreatment (20 min) of the pups with methylphenidate produced a significant, improvement in the acquisition of the PAR (Fig. 6). 

The primary drug therapies are psychostimulants which are indicated for both emotional based sleep disorders (i.e., narcolepsy) as well as ADHD. The drugs of choice are Ritalin (methylphenidate), dextroamphetamine or Cylert (pemoline), all CNS stimulants that effect the monoamine systems. The current therapies provide symptomatic relief but the current medications are not without side effects, including abuse potential, cardiovascular effects, insomnia, appetite suppression, head and stomach aches, crying and nervous mannerisms. 

Clonidine hydrochloride (Catapres), carbamazepine (Tegretol), and methylphenidate (Ritalin) are occasionally useful in intractable cases of migraine. Cyproheptadine (Periactin) may be effective in adults with migraine it is of considerable importance in the treatment of childhood migraine, and many consider it to be the drug of first choice. Dosages range from 4 to 3 mg, three to four times a day, in adults and 4 mg, two to three times a day, in children. 

Methylphenidate (Ritalin Ritalin SR Concerta Metadate) doses range from 5 mg/day bid to a maximum of 60 mg/day, divided fid. Side effects include nervousness, insomnia, loss of appetite and headaches. 

Methylphenidate (e.g., Ritalin and Concerta ) is a stimulant drug prescribed to treat hyperactivity, impulsivity, and inattention in millions of American children. Methylphenidate was first synthesized in the mid-1940s in Europe. In the United States, it was approved by the Food and Drug Administration (FDA) in 1955. The effects of methylphenidate in the human body are almost identical to those of the amphetamines. Amphetamines—the collective name for levoamphetamine (Benzedrine), dextroamphetamine (Dexedrine ), and methamphetamine (Methedrine or speed )—are known to be potent psychomotor stimulants. 

These numbers make some experts uneasy, because, like Sydney Walker III (psychiatrist and author of The Hyperactivity Hoax), they believe that Ritalin is a powerful and potentially addictive drug that masks symptoms without treating the disease and whose long-term effects on the brain are completely unknown. 1 Others, on the contrary, consider methylphenidate a mild stimulant that calms children and helps them concentrate. 

Because of these opposing viewpoints, the medical use of Ritalin has become quite controversial. Many books and articles have been published on the subject, raising the public s awareness about the drug and its effects, and leaving many to wonder whether Ritalin is a miracle pill that solves a medical problem or a way of drugging children into being more compliant and easy to handle. 

Ritalin became popular primarily because it was not an amphetamine. Amphetamines were known to have the potential for abuse and addiction. The potential for abuse of and addiction to Ritalin was still unknown. Ritalin was also preferred because it had been shown in many studies to have a rapid positive effect on children s performance, it remained in the bloodstream for only a few hours, and it had no negative effect after the children stopped taking the drug. 

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