Ritalin
Methylphenidate
Methyla-phenyl-2-piperi-dineearetate
hydrochloride
Manufactured by Ciba-Geneva, a division of Novartis
Pharmaceuticals
Indications
FDA approved medication for attention deficit disorders
and narcolepsy.Also being used as
treatment for depression and cognitive impairment in cancer patients, stroke
patients and mentally ill elderly patients.
Physiological effect
Methylphenidate is a central nervous system stimulant.Its
effect is not completely understood, but it creates a stimulant effect
by activating the brain stem arousal system and cortex. Methylphenidate
blocks dopamine and norepineprine transporters.Therapeutic
doses of oral Methylphenidate block 50-75% of dopamine transporters, increasing
extra cellular dopamine concentration in the brain.
How
does this effect attention deficit disorders?
Studies show that people with ADD and ADHD have higher
levels of dopamine transporters in their brain, which results in low concentrations
of dopamine.This dopamine deficit
in ADHD would be temporarily relieved by methylphenidate.
Methylphenidate amplifies weak dopamine signals in
people with attention deficit disorders.This
enhances task specific signals, improving attention and decreasing distractibility
in activities that normally do not hold the attention of those with attention
deficit disorders.Dopamine is involved
with the motivation and reward system; therefore an increase in dopamine
would enhance the salience of a task.
How
does it affect Narcolepsy?
Methylphenidate acts on the cerebral cortex and subcortical
structures (thalamus) to increase motor activity and mental alertness and
decrease fatigue.
Contraindications
Marked anxiety, tension, and agitation are contra
indications to Ritalin; the drug may aggravate these symptoms.Also
patients with glaucoma, motor tics, touretts syndrome and during treatment
with monoamine oxidase inhibitor.
Drug interactions
Ritalin may inhibit metabolism of coumarin anticoagulants,
anticonvulsants (Phenobarbital, diphenyldantoin, primidone), phenylbutazone
and tricyclic drugs (imipramine, clomipramine, desipramine).Adverse
affects reported in use with chlonidine.
Side effects
Nervousness and insomnia are the most common.Hypersensitivity
including skin rash, urticaria, fever, arthraglia, exfoliative dermatitis,
erythema multiforme with histopathological findings of necrotizing vascultitis,
and thrombocytopenic purpura.Also
anorexia, nausea, dizziness, palpitations, headache, dyskinesia, drowsiness,
tachycardia, angina, cardiac arrhythmia, abdominal pain, and weight loss
during prolonged therapy, abnormal liver function, psychotic symptoms of
hallucinations and paranoia.There
have been rare reports of Tourette’s syndrome, toxic psychosis.In
children, loss of appetite, abdominal pain, weight loss, insomnia, and
tachycardia may occur more frequently.Ritalin
is also found to retard growth by disrupting cycles of growth hormone released
by the pituitary gland.
Dosage
Adults: 20-40 mg daily, divided into 2-3 doses.Should
be taken 30-45 minutes before meals.
Children (6yrs and over): start with 5mg twice daily
with gradual increments of 5-10 mg weekly.
Ritalin is available in 5, 10 and 20 mg tablets and
SR tablets of 20 mg.Ritalin SR is
a sustained release tablet.
Warnings
Ritalin should be given with caution to patients
with a history of drug dependence, alcoholism and emotionally unstable
patients.Ritalin should not be
prescribed to women of childbearing age as it was found to have teratogenic
effect in rabbits.
Ritalin Facts
-Ritalin has no effect on IQ or academic achievement.
-Only acts to make children more manageable, compliant
and obedient.
-Has only suppressive behavioral effects; the reduction
of spontaneous behavior, flattening of emotions, apathetic, lacking age
typical variety and frequency of emotional expression.
-A large percent of children become robotic, lethargic,
depressed or withdrawn and uninterested in their environment.
-listed as a type II drug by the DEA
-Ritalin inhibits the exploratory drive: curiosity,
initiative, spontaneity and emotional responsiveness.
“By
reducing the most highly developed aspects of human nature-the impulses
for freedom, spontaneity, curiosity, initiative, emotional expression and
sociability-Ritalin makes children more manageable in a boring, unstimulating
and otherwise frustrating environment.”
Peter R. Breggin,
M.D.
Suggested reading: Talking back to Ritalin.By
Peter Breggin, M.D.