Methylphenidate is a drug which stimulates the central nervous system (brain) in a similar manner to that of amphetamines; however, its actions are milder than those of the amphetamines. An additional difference is that methylphenidate produces more noticeable effects on mental activities than on motor activities. Methylphenidate and amphetamines both have abuse potential. In treating children with attention-deficit hyperactivity disorder (ADHD), methylphenidate produces a calming effect. This results in a reduction in hyperactivity and an improvement in attention span. Methylphenidate was approved by the FDA in 1955.
What are the brand names available?
Ritalin, Ritalin SR, Ritalin LA
Preparation:Tablets (round): 5, 10, and 20 mg. Also available are sustained-release tablets of 20 mg (Ritalin SR) as well as long acting tablets of 20, 30, and 40 mg (Ritalin LA).
Storage: Tablets should be kept at room temperature, 15- 30°C (59-86°F).
Methylphenidate is used in the treatment of narcolepsy (uncontrollable sleepiness) and in the treatment of children with ADHD.
Dosage: The dose of methylphenidate is adjusted based on patients' responses. It may be given once, twice, or three times daily. Ritalin LA is given once daily.
Drug Interactions: The CNS stimulation effects of methylphenidate can be additive when used with other chemicals and medications that stimulate the CNS, such as caffeine (in coffee, tea, or cola drinks), and pseudoephedrine or phenylpropanolamine (in many cough-and-cold preparations). The combination of methylphenidate and monoamine oxidase inhibitors, for example, isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), and procarbazine (Matulane), should be avoided since a hypertensive crisis (severely high blood pressure) may occur. Therefore, methylphenidate should not be given to any patient within 14 days of receiving such an inhibitor. The blood pressure lowering effects of medications used to treat hypertension may be reduced by methylphenidate. As a result, blood pressure needs to be monitored when starting or stopping methylphenidate in patients who are receiving blood pressure medicines.
Pregnancy: There are no adequate studies of methylphenidate in pregnant women.
Nursing Mothers: It is not known if methylphenidate is secreted in breast milk.
Side Effects: The most common side effects with methylphenidate are nervousness, agitation, anxiety, and insomnia. Insomnia can be limited by taking the drug before noon. For children taking methylphenidate for ADHD, the most common side effects are loss of appetite, abdominal pain, weight loss, and sleep problems. The rate and severity of these side effects are less than that seen with dextroamphetamine (Dexedrine). Other side effects include nausea, vomiting, dizziness, palpitations, headache, involuntary movements, chest pain, increased heart rate, increased blood pressure, and psychosis.
There have been rare reports of Tourette's syndrome, a syndrome in which there are uncontrollable tics such as grimacing. Because of the potential for the side effects listed above, methylphenidate should be used with caution by patients who have relatives with Tourette's syndrome or have the syndrome themselves or who have severe anxiety, seizures, psychosis, emotional instability, major depression, glaucoma, or motor tics. Sudden withdrawal of long-term methylphenidate therapy may expose depression. Slow withdrawal, under medical supervision by professionals, is recommended to lead healthy life.