Other ingredients include alginic acid, magnesium stearate, potassium sorbate, starch, tribasic calcium phosphate. The onset of action is rapid and effects last four to six hours. 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. On very rare occasions, the first dose of carisoprodol has been followed by idiosyncratic symptoms appearing within minutes or hours.
Symptoms usually subside over the course of the next several hours.
Supportive and symptomatic therapy, including hospitalization, may be necessary. 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 of the mother and child. Carisoprodol is presenting 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. Because of limited clinical experience, carisoprodol is not recommended for use in patients under 12 years of age.