Ritalin

Ritalin (Methylphenidate)

     Methylphenidate hydrochloride is a mild central nervous system stimulant.  The mode of action in man is not completely understood, but methylphenidate presumably activates the brain stem arousal system and cortex to produce its stimulant effect.  There is neither specific evidence which clearly establishes the mechanism whereby methylphenidate produces its mental and behavioral effects in children, nor conclusive evidence regarding how these effects relate to the condition of the central nervous system.  Methylphenidate hydrochloride in extended-release tablets is more slowly, but as extensively absorbed as in the regular tablets.

     Bioavailability of the MD Pharmaceutical Inc. methylphenidate hydrochloride extended release tablet was compared to a sustained release reference product and an immediate release product.  The extent of absorption for the three products was similar, and the rate of absorption of the two sustained release products was not statistically different.

     In a clinical study involving adult subjects who received ER tablets, plasma concentrations of methylphenidate hydrochloride's major metabolite appeared to be greater in females than in males.  No gender differences were observed for methylphenidate hydrochloride's plasma concentration in the same subjects.

Indications

     Attention Deficit Disorders, Narcolepsy:  Methylphenidate hydrochloride is indicated as an integral proof of a total treatment program which typically includes other remedial measures (psychological, educational, social) for a stabilizing effect in children with a behavioral syndrome characterized by the following group of developmentally inappropriate symptoms:

• moderate to severe distractibility
• short attention span
• hyperactivity
• emotional liability
• impulsitivity

     The diagnosis of this syndrome should not be made with finality when these symptoms are only of comparatively recent origin.  Nonlocalizing (soft) neurological signs, learning disability and abnormal EEG may or may not be present, and a diagnosis of central nervous system dysfunction may or may not be warranted.

SPECIAL DIAGNOSTIC CONSIDERATIONS: Specific etiology of this syndrome is unknown, and there is no single diagnostic test.  Adequate diagnosis requires the use not only of medical but of special psychological, educational, and social resources.

     Characteristics commonly reported include: chronic history of short attention span, distractibility, emotional lability, impulsivity, and moderate to severe hyperactivity; minor neurological signs and abnormal EEG.  Learning may or may not be impaired.  The diagnosis must be base upon a complete history and evaluation of the child and not solely on the presence of one or more of these characteristics.

     Drug treatmetn is not indicated for all children with this syndrome.  Stimulants are not intended for use in the child who exhibits symptoms secondary to enviromental factors and /or primary psychiatric disorders, including psychosis.  Appropriate educational placement is essential and psychosocial-intervention is generally necessary.  When remedial measures alone are insufficient, the decision to prescribe stimulant medication will depend upon the physician's assessment of the chronicity and severity of the child's symptoms.

Dosage and Administration

     Dosage should be individualized according to the needs and responses of the patient.

     Tablets: Administer in divided doses 2 or 3 times daily, preferably 30 to 45 minutes before meals.  Average dosage is 20 to 30 mg daily.  Some patients will require 40 to 60 mg daily.  In others, 10 to 15 mg daily will be adequate.  Patients who are unable to sleep if medication is taken late in the day should take the last dose before 6pm.

     EXTENTED-RELEASE TABLETS: Methylphenidate hydrochloride extended release tablets have a duration of action of approximately 8 hours.  Therefore, the extended release tablets may be used in place of the immediate release tablets when the 8 hour dosage of methylphenidate hydrochloride extended release tablets corresponds to the titrated 8 hour dosage of the immediate release tablets.  Methylphenidate hydrochloride extend release tablets must be swallowed whole and never crushed or chewed.

     Methylphenidate hydrochloride should be initiated in small doses, with gradual weekly increments.  Daily dosage above 60 mg is not recommended.  If improvement is not observed after appropriate dosage adjustment over a one-month period, the drug should be discontinued.

     TABLETS: Start with 5 mg twice daily (before breakfast and lunch) with gradual increments of 5 to 10 mg weekly.

     EXTENDED-RELEASE TABLETS: Mehylphenidate hydrochloride extended release tablets have a duration of action of approximately 8 hours.  Therefore, the extended release tablets may be used in place of the immediate release tablets when the 8 hour dosage of methylphenidate hydrochloride extended release tablets corresponds to the titrated 8 hour dosage of immediate release tablets.  Methylphenidate hydrochloride extended release tablets must be swallowed whole and never crushed or chewed.  If paradoxical aggravation of symptoms or toher adverse effects occur, reduce dosage, or, if necessary, discontinue the drug.

     Methylphenidate should be periodically discontinued to assess the child's condition.  Improvement may be sustained when the drug is either temporarily or permanently discontinued.  Drug treatment should not and need not be indefinite and usually may be discontinued after puberty.