Periodic CBC, differential, and platelet counts are advised during prolonged therapy.
Drug treatment is not indicated in all cases of Attention Deficit Hyperactivity Disorders and should be considered only in light of the complete history and evaluation of the child. The decision to prescribe methylphenidate should depend on the physician's assessment of the chronicity and severity of the child's symptoms and their appropriateness for his/her age. Prescription should not depend solely on the presence of one or more of the behavioral characteristics. When these symptoms are associated with acute stress reactions, treatment with methylphenidate is usually not indicated.
Long-term effects of methylphenidate in children have not been well established.
Because methylphenidate may affect performance, patients should be cautioned against engaging in hazardous activities such as operation of automobiles or dangerous machinery.
Methylphenidate may decrease the hypotensive effect of guanethidine. Use cautiously with pressor agents and MAO inhibitors.
Human pharmacologic studies have shown that methylphenidate may inhibit the metabolism of coumarin anticoagulants, anticonvulsants (phenobarbital, diphenylhydantoin, primidone), phenylbutazone and tricyclic antidepressants (imipramine, desipramine). Downward dosage adjustments of these drugs may be required when given concomitantly with methylphenidate.
In children, loss of appetite, abdominal pain, weight loss during prolonged therapy, insomnia, and tachycardia may occur more frequently. Minor retardation of growth may also occur during prolonged therapy in children. (see Warnings)