ADVERSE REACTIONS
(See also
PRECAUTIONS)
Commonly Observed
The more commonly observed untoward events associated with the
use of buspirone not seen at an equivalent incidence among placebo-treated
patients include dizziness, nausea, headache, nervousness, lightheadedness, and
excitement.
Associated with Discontinuation of Treatment
One guide to the relative clinical importance of adverse events
associated with buspirone is provided by the frequency with which they caused
drug discontinuation during clinical testing. Approximately 10% of the 2200
anxious patients who participated in the buspirone premarketing clinical
efficacy trials in anxiety disorders lasting 3 to 4 weeks discontinued treatment
due to an adverse event. The more common events causing discontinuation
included: central nervous system disturbances (3.4%), primarily dizziness,
insomnia, nervousness, drowsiness, and lightheaded feeling; gastrointestinal
disturbances (1.2%), primarily nausea; and miscellaneous disturbances (1.1%),
primarily headache and fatigue. In addition, 3.4% of patients had multiple
complaints, none of which could be characterized as primary.
Incidence in Controlled Clinical Trials
The table that follows enumerates adverse events that occurred at
a frequency of 1% or more among buspirone patients who participated in 4-week,
controlled trials comparing buspirone with placebo. The frequencies were
obtained from pooled data for 17 trials. The prescriber should be aware that
these figures cannot be used to predict the incidence of side effects in the
course of usual medical practice where patient characteristics and other factors
differ from those which prevailed in the clinical trials. Similarly, the cited
frequencies cannot be compared with figures obtained from other clinical
investigations involving different treatments, uses, and investigators.
Comparison of the cited figures, however, does provide the prescribing physician
with some basis for estimating the relative contribution of drug and nondrug
factors to the side-effect incidence rate in the population studied.
TREATMENT-EMERGENT ADVERSE EXPERIENCE INCIDENCE IN PLACEBO-CONTROLLED CLINICAL TRIALS*
(Percent of Patients Reporting)
| Adverse
Experience | Buspirone (n=477) | Placebo (n=464) |
| Cardiovascular |
|
|
| Tachycardia/Palpitations | 1 | 1 |
| CNS |
|
|
| Dizziness | 12 | 3 |
| Drowsiness | 10 | 9 |
| Nervousness | 5 | 1 |
| Insomnia | 3 | 3 |
| Lightheadedness | 3 | - |
| Decreased Concentration | 2 | 2 |
| Excitement | 2 | - |
| Anger/Hostility | 2 | - |
| Confusion | 2 | - |
| Depression | 2 | 2 |
| EENT |
|
|
| Blurred Vision | 2 | - |
| Gastrointestinal |
|
|
| Nausea | 8 | 5 |
*Events reported by at least 1% of
buspirone patients are included.
-Incidence less than 1%
Other Events Observed During the Entire Premarketing
Evaluation of Buspirone
During its premarketing assessment, buspirone was evaluated in
over 3500 subjects. This section reports event frequencies for adverse events
occurring in approximately 3000 subjects from this group who took multiple doses
of buspirone in the dose range for which buspirone is being recommended (i.e.,
the modal daily dose of buspirone fell between 10 and 30 mg for 70% of the
patients studied) and for whom safety data were systematically collected. The
conditions and duration of exposure to buspirone varied greatly, involving
well-controlled studies as well as experience in open and uncontrolled clinical
settings. As part of the total experience gained in clinical studies, various
adverse events were reported. In the absence of appropriate controls in some of
the studies, a causal relationship to buspirone hydrochloride, treatment cannot
be determined. The list includes all undesirable events reasonably associated
with the use of the drug.
The following enumeration by organ system describes events in terms of their
relative frequency of reporting in this database.
Events of major clinical importance are also described in the PRECAUTIONS section.
The following definitions of frequency are used: Frequent adverse events are
defined as those occurring in at least 1/100 patients. Infrequent adverse events
are those occurring in 1/100 to 1/1000 patients, while rare events are those
occurring in less than 1/1000 patients.
Cardiovascular
Frequent was nonspecific chest pain; infrequent were syncope,
hypotension, and hypertension; rare were cerebrovascular accident, congestive
heart failure, myocardial infarction, cardiomyopathy, and bradycardia.
Central Nervous System
Frequent were dream disturbances; infrequent were
depersonalization, dysphoria, noise intolerance, euphoria, akathisia,
fearfulness, loss of interest, dissociative reaction, hallucinations,
involuntary movements, slowed reaction time, suicidal ideation, and seizures;
rare were feelings of claustrophobia, cold intolerance, stupor, and slurred
speech and psychosis.
EENT
Frequent were tinnitus, sore throat, and nasal congestion;
infrequent were redness and itching of the eyes, altered taste, altered smell,
and conjunctivitis; rare were inner ear abnormality, eye pain, photophobia, and
pressure on eyes.
Endocrine
Rare were galactorrhea and thyroid abnormality.
Gastrointestinal
Infrequent were flatulence, anorexia, increased appetite,
salivation, irritable colon, and rectal bleeding; rare was burning of the
tongue.
Genitourinary
Infrequent were urinary frequency, urinary hesitancy, menstrual
irregularity and spotting, and dysuria; rare were amenorrhea, pelvic
inflammatory disease, enuresis, and nocturia.
Musculoskeletal
Infrequent were muscle cramps, muscle spasms, rigid/stiff
muscles, and arthralgias; rare was muscle weakness.
Respiratory
Infrequent were hyperventilation, shortness of breath, and chest
congestion; rare was epistaxis
Sexual Function
Infrequent were decreased or increased libido; rare were delayed
ejaculation and impotence.
Skin
Infrequent were edema, pruritus, flushing, easy bruising, hair
loss, dry skin, facial edema, and blisters; rare were acne and thinning of
nails.
Clinical Laboratory
Infrequent were increases in hepatic aminotransferases (SGOT,
SGPT); rare were eosinophilia, leukopenia, and thrombocytopenia.
Miscellaneous
Infrequent were weight gain, fever, roaring sensation in the
head, weight loss, and malaise; rare were alcohol abuse, bleeding disturbance,
loss of voice, and hiccoughs.
Postintroduction Clinical Experience
Postmarketing experience has shown an adverse experience profile
similar to that given above. Voluntary reports since introduction have included
rare occurrences of allergic reactions (including urticaria), angioedema,
cogwheel rigidity, dizziness (rarely reported as vertigo), dystonic reactions,
ataxias, extrapyramidal symptoms, dyskinesias (acute and tardive), ecchymosis,
emotional lability, serotonin syndrome, transient difficulty with recall,
urinary retention, and visual changes (including tunnel vision). Because of the
uncontrolled nature of these spontaneous reports, a causal relationship to
buspirone treatment has not been determined
