WARNINGS
Serious Cardiovascular Events
Sudden Death in Patients With Pre-existing Structural
Cardiac Abnormalities or Other Serious Heart Problems
Children And Adolescents
Sudden death has been reported in association with CNS
stimulant treatment at usual doses in children and adolescents with structural
cardiac abnormalities or other serious heart problems. Although some serious
heart problems alone carry an increased risk of sudden death, stimulant
products generally should not be used in children or adolescents with known
serious structural cardiac abnormalities, cardiomyopathy, serious heart rhythm
abnormalities, or other serious cardiac problems that may place them at
increased vulnerability to the sympathomimetic effects of a stimulant drug.
Adults
Sudden deaths, stroke, and myocardial infarction have
been reported in adults taking stimulant drugs at usual doses for ADHD.
Although the role of stimulants in these adult cases is also unknown, adults
have a greater likelihood than children of having serious structural cardiac
abnormalities, cardiomyopathy, serious heart rhythm abnormalities, coronary
artery disease, or other serious cardiac problems. Adults with such
abnormalities should also generally not be treated with stimulant drugs (see CONTRAINDICATIONS).
Hypertension And Other Cardiovascular Conditions
Stimulant medications cause a modest increase in average
blood pressure (about 2-4 mmHg) and average heart rate (about 3-6 bpm), and
individuals may have larger increases. While the mean changes alone would not
be expected to have short-term consequences, all patients should be monitored
for larger changes in heart rate and blood pressure. Caution is indicated in
treating patients whose underlying medical conditions might be compromised by
increases in blood pressure or heart rate, e.g., those with pre-existing
hypertension, heart failure, recent myocardial infarction, or ventricular arrhythmia (see CONTRAINDICATIONS).
Assessing Cardiovascular Status In Patients Being Treated
With Stimulant Medications
Children, adolescents, or adults who are being considered
for treatment with stimulant medications should have a careful history
(including assessment for a family history of sudden death or ventricular
arrhythmia) and physical exam to assess for the presence of cardiac disease,
and should receive further cardiac evaluation if findings suggest such disease
(e.g., electrocardiogram and echocardiogram). Patients who develop symptoms
such as exertional chest pain, unexplained syncope, or other symptoms
suggestive of cardiac disease during stimulant treatment should undergo a
prompt cardiac evaluation.
Psychiatric Adverse Events
Pre-Existing Psychosis
Administration of stimulants may exacerbate symptoms of
behavior disturbance and thought disorder in patients with a pre-existing psychotic
disorder.
Bipolar Illness
Particular care should be taken in using stimulants to
treat ADHD in patients with comorbid bipolar disorder because of concern for
possible induction of a mixed/manic episode in such patients. Prior to
initiating treatment with a stimulant, patients with comorbid depressive
symptoms should be adequately screened to determine if they are at risk for
bipolar disorder; such screening should include a detailed psychiatric history,
including a family history of suicide, bipolar disorder, and depression.
Emergence Of New Psychotic Or Manic Symptoms
Treatment emergent psychotic or manic symptoms, e.g.,
hallucinations, delusional thinking, or mania in children and adolescents
without a prior history of psychotic illness or mania can be caused by
stimulants at usual doses. If such symptoms occur, consideration should be
given to a possible causal role of the stimulant, and discontinuation of
treatment may be appropriate. In a pooled analysis of multiple short-term,
placebo-controlled studies, such symptoms occurred in about 0.1% (4 patients
with events out of 3,482 exposed to methylphenidate or amphetamine for several
weeks at usual doses) of stimulant-treated patients compared to 0 in
placebo-treated patients.
Aggression
Aggressive behavior or hostility is often observed in
children and adolescents with ADHD, and has been reported in clinical trials
and the postmarketing experience of some medications indicated for the
treatment of ADHD. Although there is no systematic evidence that stimulants
cause aggressive behavior or hostility, patients beginning treatment for ADHD
should be monitored for the appearance of, or worsening of, aggressive behavior
or hostility.
Long-Term Suppression Of Growth
Careful follow-up of weight and height in children ages 7
to 10 years who were randomized to either methylphenidate or non-medication
treatment groups over 14 months, as well as in naturalistic subgroups of newly
methylphenidate-treated and non-medication treated children older than 36
months (to the ages of 10 to 13 years), suggests that consistently medicated
children (i.e., treatment for 7 days per week throughout the year) have a
temporary slowing in growth rate (on average, a total of about 2 cm less growth
in height and 2.7 kg less growth in weight over 3 years), without evidence of
growth rebound during this period of development. Published data are inadequate
to determine whether chronic use of amphetamines may cause a similar
suppression of growth, however, it is anticipated that they likely have this
effect as well. Therefore, growth should be monitored during treatment with
stimulants, and patients who are not growing or gaining height or weight as
expected may need to have their treatment interrupted.
Seizures
There is some clinical evidence that stimulants may lower
the convulsive threshold in patients with prior history of seizures, in
patients with prior EEG abnormalities in absence of seizures, and, very rarely,
in patients without a history of seizures and no prior EEG evidence of
seizures. In the presence of seizures, the drug should be discontinued.
Peripheral Vasculopathy, Including Raynaud's Phenomenon
Stimulants, including DEXEDRINE, used to treat ADHD are
associated with peripheral vasculopathy, including Raynaud's phenomenon. Signs
and symptoms are usually intermittent and mild; however, very rare sequelae
include digital ulceration and/or soft tissue breakdown. Effects of peripheral
vasculopathy, including Raynaud's phenomenon, were observed in post-marketing
reports at different times and at therapeutic doses in all age groups
throughout the course of treatment. Signs and symptoms generally improve after
reduction in dose or discontinuation of drug. Careful observation for digital
changes is necessary during treatment with ADHD stimulants. Further clinical
evaluation (e.g., rheumatology referral) may be appropriate for certain
patients.
Serotonin Syndrome
Serotonin syndrome, a potentially life-threatening
reaction, may occur when amphetamines are used in combination with other drugs
that affect the serotonergic neurotransmitter systems such as monoamine oxidase
inhibitors (MAOIs), selective serotonin reuptake inhibitors (SSRIs), serotonin
norepinephrine reuptake inhibitors (SNRIs), triptans, tricyclic antidepressants,
fentanyl, lithium, tramadol, tryptophan, buspirone, and St. John's Wort [see DRUG
INTERACTIONS)]. Amphetamines and amphetamine derivatives are known to be metabolized,
to some degree, by cytochrome P450 2D6 (CYP2D6) and display minor inhibition of
CYP2D6 metabolism [see CLINICAL PHARMACOLOGY]. The potential for a
pharmacokinetic interaction exists with the co-administration of CYP2D6
inhibitors which may increase the risk with increased exposure to DEXEDRINE. In
these situations, consider an alternative non-serotonergic drug or an
alternative drug that does not inhibit CYP2D6 [see DRUG INTERACTIONS].
Serotonin syndrome symptoms may include mental status
changes (e.g., agitation, hallucinations, delirium, and coma), autonomic
instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis,
flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity,
myoclonus, hyperreflexia, incoordination), seizures, and/or gastrointestinal
symptoms (e.g., nausea, vomiting, diarrhea).
Concomitant use of DEXEDRINE with MAOI drugs is
contraindicated [see CONTRAINDICATIONS].
Discontinue treatment with DEXEDRINE and any concomitant
serotonergic agents immediately if the above symptoms occur, and initiate
supportive symptomatic treatment. If concomitant use of DEXEDRINE with other
serotonergic drugs or CYP2D6 inhibitors is clinically warranted, initiate
DEXEDRINE with lower doses, monitor patients for the emergence of serotonin
syndrome during drug initiation or titration, and inform patients of the
increased risk for serotonin syndrome.
Visual Disturbance
Difficulties with accommodation and blurring of vision
have been reported with stimulant treatment.