A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Dexedrine Side Effects, and Drug Interactions - Dextroamphetamine
Dexedrine Side Effects, and Drug Interactions - Dextroamphetamine
SIDE EFFECTS
Cardiovascular
Palpitations, tachycardia,
elevation of blood
pressure. There have been isolated reports of cardiomyopathy
associated with chronic
amphetamine use.
Central Nervous System
Psychotic episodes at recommended doses (rare), overstimulation,
restlessness, dizziness, insomnia,
euphoria, dyskinesia,
dysphoria, tremor,
headache, exacerbation of motor
and phonic tics and Tourette's
syndrome.
Gastrointestinal
Dryness of the mouth,
unpleasant taste, diarrhea,
constipation, other
gastrointestinal disturbances. Anorexia and weight
loss may occur as undesirable
effects.
Allergic
Urticaria.
Endocrine
Impotence, changes in libido.
DRUG ABUSE AND DEPENDENCE
Dextroamphetamine sulfate
is a Schedule II controlled substance.
Amphetamines have been extensively abused. Tolerance, extreme psychological
dependence and severe social disability
have occurred. There are reports of patients who have increased
the dosage to many times
that recommended. Abrupt cessation following prolonged high dosage
administration
results in extreme fatigue
and mental depression;
changes are also noted on the sleep EEG.
Manifestations of chronic
intoxication with
amphetamines include severe dermatoses, marked insomnia,
irritability, hyperactivity
and personality changes. The most severe manifestation
of chronic intoxication
is psychosis, often clinically indistinguishable from schizophrenia.
This is rare with oral amphetamines.
DRUG INTERACTIONS
Acidifying Agents
Gastrointestinal acidifying agents (guanethidine, reserpine, glutamic
acid HCl, ascorbic acid,
fruit juices, etc.) lower
absorption of amphetamines,
Urinary acidifying agents (ammonium chloride, sodium
acid phosphate, etc.) increase
the concentration
of the ionized species
of the amphetamine
molecule, thereby increasing urinary
excretion. Both groups of agents lower blood levels and efficacy
of amphetamines.
Adrenergic Blockers
Adrenergic blockers are inhibited by amphetamines.
Alkalinizing Agents
Gastrointestinal alkalinizing agents (sodium bicarbonate, etc.)
increase absorption of amphetamines. Urinary alkalinizing agents
(acetazolamide, some thiazides) increase the concentration
of the non-ionized species
of the amphetamine
molecule, thereby decreasing
urinary excretion. Both
groups by agents increase blood
levels and therefore potentiate
the action of amphetamines.
Antidepressants tricyclic:
Amphetamines may enhance the activity
of tricyclic or sympathometic agents; d-amphetamine with desipramine
or protriptyline and possibly other tricyclics cause
striking and sustained increases in the concentration of d-amphetamine
in the brain; cardiovascular
effects can be potentiated.
MAO Inhibitors
MAOI antidepressants, as well as a metabolite
of furazolidone, slow amphetamine metabolism. This slowing potentiates
amphetamines, increasing their effect
on the release of norepinephrine
and other monoamines from adrenergic nerve
endings; this can cause
headaches and other signs of hypertensive crisis. A variety
of neurological toxic
effects and malignant
hyperpyrexia can occur, sometimes with fatal
results.
Antihistamines
Amphetamines may counteract
the sedative effect
of antihistamines.
Antihypertensives
Amphetamines may antagonize the hypotensive
effects of antihypertensives.
Chlorpromazine
Chlorpromazine blocks dopamine and norepinephrine
reuptake, thus inhibiting the central
stimulant effects
of amphetamines, and can be used to treat amphetamine poisoning.
Ethosuximide
Amphetamines may delay intestinal
absorption of ethosuximide.
Haloperidol
Haloperidol blocks dopamine and norepinephrins reuptake, thus inhibiting
the central stimulant
effects of amphetamines.
Lithium Carbonate
The stimulatory effects of amphetamines may be inhibited by lithium
carbonate.
Meperidine
Amphetamines potentiate
the analgesic effect
of meperidine.
Methenamine Therapy
Urinary excretion
of amphetamines is increased, and efficacy
is reduced, by acidifying agents used in methenamine
therapy.
Norepinephrine
Amphetamines enhance the adrenergic
effect of norepinephrine.
Phenobarbital
Amphetamines may delay administration
of phenobarbital
and may produce an intestinal
absorption of phenobarbital;
coadministration
of phenobarbital may produce a co-synergistic anticonvulsant
action.
Phenytoin
Amphetamines may delay intestinal
absorption of phenytoin;
co-administration of phenytoin
may produce a synergistic
anticonvulsant
action.
Propoxyphene
In cases of propoxyphene overdosage, amphetamine
CNS stimulation
is potentiated and fatal
convulsions can occur.
Veratrum Alkaloids
Amphetamines inhibit the hypotensive
effect of veratrum alkaloids.
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