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
Fioricet Side Effects, and Drug Interactions - Butalbital, Acetaminophen and Caffeine
Fioricet Side Effects, and Drug Interactions - Butalbital, Acetaminophen and Caffeine
SIDE EFFECTS
Frequently Observed
The most frequently reported adverse reactions are drowsiness,
light-headedness, dizziness, sedation,
shortness of breath, nausea,
vomiting, abdominal
pain, and intoxicated feeling.
Infrequently Observed
All adverse events tabulated below are classified as infrequent.
Central Nervous: headache,
shaky feeling, tingling, agitation, fainting, fatigue,
heavy eyelids, high energy, hot
spells, numbness, sluggishness, seizure. Mental confusion,
excitement or depression
can also occur due to intolerance, particularly in elderly or debilitated
patients, or due to overdosage of butalbital.
Autonomic Nervous: dry mouth,
hyperhidrosis.
Gastrointestinal: difficulty swallowing, heartburn,
flatulence, constipation.
Cardiovascular: tachycardia.
Musculoskeletal: leg
pain, muscle
fatigue.
Genitourinary: diuresis.
Miscellaneous: pruritus,
fever, earache, nasal
congestion, tinnitus, euphoria,
allergic reactions.
Several cases of dermatological reactions, including toxic
epidermal necrolysis
and erythema multiforme,
have been reported.
The following adverse drug
events may be borne in mind
as potential effects of the components of this product. Potential
effects of high dosage are listed in the OVERDOSAGE
section.
Acetaminophen: allergic
reactions, rash, thrombocytopenia,
agranulocytosis.
Caffeine: cardiac stimulation, irritability, tremor,
dependence, nephrotoxicity, hyperglycemia.
DRUG ABUSE AND DEPENDENCE
Abuse and Dependence
Butalbital: Barbiturates may be habit-forming: Tolerance,
psychological dependence,
and physical dependence
may occur especially following prolonged use of high doses of barbiturates.
The average daily dose
for the barbiturate addict
is usually about 1500 mg. As
tolerance to barbiturates
develops, the amount needed to maintain the same level of intoxication
increases; tolerance
to a fatal dosage,
however, does not increase more than two- fold. As
this occurs, the margin
between an intoxication dosage and fatal
dosage becomes smaller.
The lethaldose of a barbiturate is far less if alcohol
is also ingested. Major withdrawal
symptoms (convulsions and delirium) may occur within 16 hours and
last up to 5 days after abrupt cessation of these drugs. Intensity
of withdrawal symptoms
gradually declines over a period
of approximately 15 days. Treatment of barbiturate dependence consists
of cautious and gradual withdrawal
of the drug. Barbiturate-dependent patients can be withdrawn by
using a number of different
withdrawal regimens.
One method involves initiating
treatment at the patient’s
regular dosage level
and gradually decreasing the daily dosage
as tolerated by the patient.
DRUG INTERACTIONS
The CNS effects of butalbital
may be enhanced by monoamine
oxidase (MAO) inhibitors.
Butalbital, acetaminophen
and caffeine may enhance
the effects of: other narcotic
analgesics, alcohol,
general anesthetics, tranquilizers such as chlordiazepoxide, sedative-hypnotics,
or other CNS depressants,
causing increased CNS depression.
Drug/Laboratory Test Interactions
Acetaminophen may produce false-positive
test results for urinary
5-hydroxyindoleacetic acid.
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