CARISOPRODOL
DESCRIPTION:
CARICARISOMA (carisoprodol) Tablets, USP is available as 350 mg round, white tablets.
Chemically, carisoprodol is N-isopropyl-2-methyl-2-propyl- 1,3-propanediol
dicarbamate. Carisoprodol is a white, crystalline powder, having a mild,
characteristic odor and a bitter taste. It is very slightly soluble in water;
freely soluble in alcohol, in chloroform, and in acetone; its solubility is
practically independent of pH. Carisoprodol is present as a racemic mixture. The
molecular formula is C12H24N2O4, with a molecular weight of 260.33.
Other Ingredients: alginic acid, magnesium stearate, potassium sorbate, starch,
tribasic calcium phosphate.
ACTIONS/CLINICAL PHARMACOLOGY:
Carisoprodol produces muscle relaxation in animals by blocking interneuronal
activity in the descending reticular formation and spinal cord. The onset of
action is rapid and effects last four to six hours.
INDICATIONS AND USAGE:
Carisoprodol is indicated as an adjunct to rest, physical therapy, and other
measures for the relief of discomfort associated with acute, painful
musculoskeletal conditions. The mode of action of this drug has not been clearly
identified, but may be related to its sedative properties. Carisoprodol does not
directly relax tense skeletal muscles in man.
CONTRAINDICATIONS:
Acute intermittent porphyria as well as allergic or idiosyncratic reactions to
carisoprodol or related compounds.
WARNINGS:
IDIOSYNCRATIC REACTIONS--On very rare occasions, the first dose of carisoprodol
has been followed by idiosyncratic symptoms appearing within minutes or hours.
Symptoms reported include: extreme weakness, transient quadriplegia, dizziness,
ataxia, temporary loss of vision, diplopia, mydriasis, dysarthria, agitation,
euphoria, confusion, and disorientation. Symptoms usually subside over the
course of the next several hours. Supportive and symptomatic therapy, including
hospitalization, may be necessary.
USAGE IN PREGNANCY AND LACTATION--Safe usage of this drug in pregnancy or
lactation has not been established. Therefore, use of this drug in pregnancy, in
nursing mothers, or in women of childbearing potential requires that the
potential benefits of the drug be weighed against the potential hazards to
mother and child. Carisoprodol is present in breast milk of lactating mothers at
concentrations two to four times that of maternal plasma. This factor should be
taken into account when use of the drug is contemplated in breast-feeding
patients.
USAGE IN CHILDREN--Because of limited clinical experience, CARICARISOMA is not
recommended for use in patients under 12 years of age.
POTENTIALLY HAZARDOUS TASKS--Patients should be warned that this drug may impair
the mental and /or physical abilities required for the performance of
potentially hazardous tasks such as driving a motor vehicle or operating
machinery.
ADDITIVE EFFECTS--Since the effects of carisoprodol and alcohol or carisoprodol
and other CNS depressants or psychotropic drugs may be additive, appropriate
caution should be exercised with patients who take more than one of these agents
simultaneously.
DRUG DEPENDENCE--In dogs, no withdrawal symptoms occurred after abrupt cessation
of carisoprodol from dosages as high as 1 gm/kg/day. In a study in man, abrupt
cessation of 100 mg/kg/day (about five times the recommended daily adult dosage)
was followed in some subjects by mild withdrawal symptoms such as abdominal
cramps, insomnia, chilliness, headache, and nausea. Delirium and convulsions did
not occur. In clinical use, psychological dependence and abuse have been rare,
and there have been no reports of significant abstinence signs. Nevertheless,
the drug should be used with caution in addiction- prone individuals.
PRECAUTIONS:
Carisoprodol is metabolized in the liver and excreted by the kidney; to avoid
its excess accumulation, caution should be exercised in administration to
patients with compromised liver or kidney function.
ADVERSE REACTIONS:
Central Nervous System--Drowsiness and other CNS effects may require dosage
reduction. Also observed: dizziness, vertigo, ataxia, tremor, agitation,
irritability, headache, depressive reactions, syncope, and insomnia. (See also
Idiosyncratic Reactions under "Warnings.")
Allergic Or Idiosyncratic--Allergic or idiosyncratic reactions occasionally
develop. They are usually seen within the period of the first to fourth dose in
patients having had no previous contact with the drug. Skin rash, erythema
multiforme, pruritus, eosinophilia, and fixed drug eruption with cross reaction
to meprobamate have been reported with carisoprodol. Severe reactions have been
manifested by asthmatic episodes, fever, weakness, dizziness, angioneurotic
edema, smarting eyes, hypotension, and anaphylactoid shock. (See also
Idiosyncratic Reactions under "Warnings.")
In case of allergic or idiosyncratic reactions to carisoprodol, discontinue the
drug and initiate appropriate symptomatic therapy, which may include
epinephrine, antihistamines, and in severe cases corticosteroids. In evaluating
possible allergic reactions, also consider allergy to excipients (information on
excipients is available to physicians on request).
Cardiovascular--Tachycardia, postural hypotension, and facial flushing.
Gastrointestinal--Nausea, vomiting, hiccup, and epigastric distress.
Hematologic--Leukopenia, in which other drugs or viral infection may have been
responsible, and pancytopenia, attributed to phenylbutazone, have been reported.
No serious blood dyscrasias have been attributed to carisoprodol.
DOSAGE AND ADMINISTRATION:
The usual adult dosage of CARICARISOMA (carisoprodol) Tablets, USP is one 350 mg
tablet, three times daily and at bedtime. Usage in patients under age 12 is not
recommended.
OVERDOSAGE:
Overdosage of carisoprodol has produced stupor, coma, shock, respiratory
depression, and, very rarely, death. The effects of an overdosage of
carisoprodol and alcohol or other CNS depressants or psychotropic agents can be
additive even when one of the drugs has been taken in the usual recommended
dosage. Any drug remaining in the stomach should be removed and symptomatic
therapy given. Should respiration or blood pressure become compromised,
respiratory assistance, central nervous system stimulants, and pressor agents
should be administered cautiously as indicated. Carisoprodol is metabolized in
the liver and excreted by the kidney. Although carisoprodol overdosage
experience is limited, the following types of treatment have been used
successfully with the related drug meprobamate: diuresis, osmotic (mannitol)
diuresis, peritoneal dialysis, and hemodialysis (carisoprodol is dialyzable).
Careful monitoring of urinary output is necessary and caution should be taken to
avoid overhydration. Observe for possible relapse due to incomplete gastric
emptying and delayed absorption. Carisoprodol can be measured in biological
fluids by gas chromatography (Douglas, J. F. et al.: J Pharm Sci 58: 145, 1969).
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