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ADHD: Parent
information sheet
The term
attention-deficit hyperactivity disorder (ADHD) was introduced in
1987 in the new edition of the Diagnostic and Statistical
Manual-III-R, published by the American Psychiatric Association.
The change in terminology calls attention to the essential features
of the syndrome: developmentally inappropriate inattention,
impulsivity, and hyperactivity (when present). The confusion
surrounding this entity is reflected in the variety of terms used
in the past: hyperkinetic reaction of childhood, hyperkinetic
syndrome, hyperactive child syndrome, minimal brain damage, minimal
brain dysfunction (MBD), minimal cerebral dysfunction, minor
cerebral dysfunction, and functional behavior problem (FBP), among
others.
Associated or secondary features vary according to age and include
obstinacy, stubbornness, negativism, bossiness, bullying, mood
swings, excitability with a tendency to overreact, low frustration
tolerance, temper outbursts, low self-esteem, and lack of response
to discipline. Also encountered are coordination problems, speech
impairment, perceptual disorders, and learning difficulties. ADHD
is found in 3% of prepubertal children in the U.S., and is
approximately 10 times more common in boys than in
girls.
The onset of
ADHD is typically by age 3, although frequently the disorder does
not come to professional attention until the child enters school.
Academic difficulties are common and social functioning is often
impaired. Family patterns are disrupted by the child, and there is
a fairly strong likelihood that one of the parents has, or had,
ADHD (suggesting a genetic or hereditary pattern). In some cases
the disorder is self-limited and disappears around puberty. In
others it continues into adolescence and throughout adult life.
With many, the hyperactivity disappears at a certain point, but the
attention problems and impulsivity persist.
DRUGS USED
FOR ADHD
I.
Stimulant Drugs
A.
Amphetamines
-
Amphetamine
-
Dextroamphetamine
-
Methamphetamine
-
Benzedrine®
-
Dexedrine®
-
Desoxyn®, Methedrine®
B.
Non-Amphetamines
-
Methylphenidate
- Pemoline
Ritalin®
-
Cylert®
II.
Antidepressant Drugs
DRUG
TREATMENT
The history of stimulant drug use dates back to the
discovery by Bradley in 1937 of the therapeutic effects of
Benzedrine® on behaviorally disturbed children. In 1948,
Dexedrine® was introduced, with the advantage of having equal
efficacy at half the dose. Ritalin® was released in 1954 with
the hope that it would have fewer side effects and less abuse
potential. Although they were initially also popular as
antidepressants and diet pills, stimulant drugs are rarely used for
those purposes today.
In 1957,
Laufer described the "hyperkinetic im-pulse disorder," which he
believed was caused by a maturational lag in the development of the
central nervous system. He asserted that stimulant drugs were the
treatment of choice for this disorder, and postulated that they
acted by stimulating the mid-brain, placing it in a more
synchronous balance with the outer cerebral cortex. This was an
oversimplification, but the exact mechanism of action of these
drugs is still unknown.
The most
frequently used of the stimulant drugs is Ritalin®, followed by
Dexedrine®, Desoxyn®, Ben-zedrine®, and Cylert®.
Dexedrine®, Benzedrine®, and Desoxyn® are amphetamine
preparations; Ritalin® and Cylert® are nonamphetamines.
Cylert® works differently from the other drugs, taking 2-4
weeks before therapeutic effects are noted. Tofranil® is an
antidepressant that is also used to treat bedwetting, panic
disorders, school phobia, and ADHD. Various dietary programs have
been attempted, including the Feingold program (curtailing food
additives), low sugar diets, vegetarian diets, etc. None of these
dietary regimens have proven to be successful when put to careful
scientific scrutiny.
MODE OF
DRUG ACTION
It
is postulated that stimulant drugs act by affecting the
catecholamine neurotransmitters (especially dopamine) in the brain.
Some believe that ADHD develops from a dopamine deficiency, which
can be corrected by stimulant drug treatment. At one time it was
felt that the stimulant drugs created a paradoxical (opposite and
unexpected) reaction (calming and sedation) in ADHD youngsters, and
that this response was diagnostic. This is no longer believed to be
the case, as the response to stimulant drugs is neither
paradoxical, nor specific. Children with conduct disorders and no
evidence of ADHD may also respond to these drugs. Likewise, studies
with normal and enuretic (bedwetting) children have shown that many
experience a calming effect rather than the expected
stimulation.
Because of
their relative safety, the stimulant drugs remain the treatment of
choice in treating ADHD. The drugs are unquestionably successful in
decreasing hyperactivity, lessening impulsivity, and improving
attention span in approximately 70% of those treated. As a result
of improved interactions with family members, peers, and teachers,
the drug-treated children feel better about themselves, and
self-esteem rises. At the present time, however, there is some
controversy as to the degree of learning and memory improvement
resulting from the treatment of ADHD children with stimulant drugs.
Overall, the ideal approach is one in which the children are
involved in individual, group, or family therapy, along with drug
treatment.
CONTRAINDICATIONS
1. Known
hypersensitivity or allergic reaction to the drug.
2.
Seizure history.
3.
Glaucoma.
4.
Hypertension.
5.
History of tics.
6.
Hyperthyroidism.
7.
Pregnancy.
DRUG
INTERACTIONS
The
drugs may decrease the effects of some antihypertensive drugs
(e.g., Ismelin®). They should be used cautiously with pressor
agents (adrenalin-like drugs). They may affect the liver metabolism
of certain anticoagulants, anticonvulsants, and tricyclic
antidepressants. Insulin requirements in diabetic patients may be
altered when the drugs are co-mixed.
PRESCRIBING INFORMATION
Ritalin® is available in 5, 10, and 20 mg tablets. A new
preparation, Ritalin® SR®, is a sustained-release product
with effects lasting 6-8 hours (twice as long as the standard
preparation). The usual starting dosage of the standard
Ritalin® for children under 8 is a single 5 mg tablet in the
morning, and for children over 8 is a single 10 mg tablet in the
morning. Each week the daily dosage can be increased by 5 mg and 10
mg a day, respectively. Usually the tablets are taken at breakfast
and lunch; occasionally an after-school dose is necessary. The
tablets should be taken on an empty stomach, ½ hour before
or after meals. The total maximum dosage should not exceed 60 mg,
although under extreme situations 80 mg/day dosages are
prescribed.
There
has been little experience with the sustained-release SR®
preparation. One study showed that it was as effective as the
shorter-acting preparation, and had no difference in side effects.
The SR® preparation comes in 20 mg tablets, roughly equal to
two of the standard 10 mg tablets taken 4 hours apart. Generally,
the initial dosage adjustments are done with the standard
preparation, which is later switched to the SR® brand for
maintenance treatment.
The
amphetamines are quite similar in their pharmacological makeup.
Dexedrine® comes in 5, 10, and 15 mg tablets and capsules; in a
liquid elixir preparation with 5 mg per teaspoon; and in
slow-release capsules of 5, 10, and 15 mg. The dosage is
approximately half that of Ritalin®. Benzedrine is available in
5, 10, and 15 mg tablets; and in a 15 mg sustained-release capsule.
The dosage range is similar to Dexedrine® (S-60 mg/day).
Desoxyn® is available in 2.5 and S mg tablets; and in 5, 10,
and 15 mg sustained-release capsules. Pharmacological actions are
similar to those of Dexedrine® and Benzedrine®.
Cylert®
is given once a day, giving it an advantage over the shorter-acting
preparations. It has a gradual onset of action; significant
clinical benefits may not be evident until the 3rd or 4th week of
treatment and they may take as long as 6 weeks. The drug is
available in 18.75, 37.5, and 75 mg tablets; and in 37.5 mg
chewable tablets. The recommended starting dose is 37.5 mg, and the
dosage is increased in daily increments of 18.75 mg per week until
the desired clinical effects are reached. The effective daily dose
for most patients is in the range between 56.25-75 mg. The maximum
daily dose is 112.5 mg.
Of those
ADHD-children treated with stimulant drugs, 66%-75% will improve
and 5%-10% will get worse. It is always important to verify that
the medication is actually being taken, as some children will
refuse to do so as a means of rebellion or defiance. There is a
marked variation in drug response among different children, and
even within an individual child on different days. Some children
will not respond unless they are placed on extremely high doses, or
on 4-5 doses a day, probably as a result of accelerated metabolism
(drug breakdown).
Tolerance to
the stimulant drugs may develop, requiring an increase in dosage
after the child has maintained nicely on a particular dosage for a
year or so. Children who respond to one of these stimulant drugs
will probably respond as well to any of the others. There are
cases, however, in which a child will respond favorably to one drug
but not another. Also, there is no evidence that children treated
for years with stimulant drugs will have a greater likelihood of
abusing drugs or narcotics during their adolescent
years.
SIDE
EFFECTS
The
most common side effects encountered with stimulant drugs are: loss
of appetite, weight loss, sleeping problems, irritability,
restlessness, stomachache, headache, rapid heart rate, elevated
blood pressure, sudden deterioration of behavior, and symptoms of
depression with sadness, crying, and withdrawn behavior. Two of the
most disconcerting side effects are the intensification of tics
(muscle twitches of the face and other parts of the body), and
suppression of growth. It is rare that stimulant drugs cause tics,
but they may activate an underlying (latent) tic condition. There
is some concern that this could even lead to a severe tic condition
called Tour-ette's Syndrome. As a result, ADHD children with tics
are often treated with the neuroleptic tranquilizer, Haldol®,
either alone or in combination with one of the stimulant drugs
(Benzedrine® may be the safest under these
circumstances).
The growth
retardation problem has caused considerable controversy and concern
since an article written in 1972 described suppression in growth of
ADHD children who had undergone long-term stimulant drug treatment.
Subsequent studies have varied markedly in their findings. One
study of adolescents who took the drugs as children showed no
growth suppression. Another study demonstrated growth suppression
during the 1st year, but none during the 2nd year of drug
treatment. Others have demonstrated a rebound growth spurt when the
drug is withdrawn, or even in those still taking the medication.
There is also some indication that taller children are more
vulnerable to growth suppression effects than are those who are
smaller. The problems appear to be dose-related, occurring in
Dexedrine® doses of 15 mg or more per day, and Ritalin®
doses greater than 30-40 mg per day. Experts now believe that any
risk of growth suppression in most children is minimal and is
mainly in body weight rather than height. Even the effects on
weight are small, averaging approximately 2 pounds during the first
year.
As a result
of the growth retardation scare, many clinicians are suggesting
that the drugs be given only on school days and not on weekends,
holidays, or vacations. Realistically, most parents are unable to
tolerate the deterioration in behavior that ensues when the
medication is withdrawn. At the very least, the drugs should be
withdrawn once a year to reestablish the need to continue the
medication. A popular approach is to discontinue the stimulant
drugs during the first 2 weeks of November. If the medication is
still required, it will be apparent soon enough, and not too late
to endanger the child's grades and reputation among schoolmates and
teachers.
Other rare
side effects include: irregular heartbeat, hair loss, decreased
white blood cell count, anemia, and rash. Elevated liver function
tests may be associated with Cylert®. A rare hypersensitivity
reaction consists of hives, fever, and easy bruising. Occasionally,
ADHD children on stimulant drugs will experience a personality
change characterized by dejection, lifelessness, tearfulness, and
over sensitivity Conversely, some may develop a state of
excitement, confusion, and withdrawal.
Adapted
from The Handbook of Modern Psychopharmacology. Copyright 1983 by
BMH Clinical Laboratories.
Reprinted with permission
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