Adults-Oral. The only oral dose clearly shown to be effective is 160 mg per day (in 4 equally divided doses). Since this dose is associated with a significant incidence of side effects, it is prudent to begin with 80 mg per day (in 4 equally divided doses). Depending upon the patient’s response during the first week of therapy, the dose should be increased to 160 mg per day unless side effects limit dosage escalation. If efficacy is not achieved within 2 weeks or side effects require doses below 80 mg per day, the drug should be discontinued. Documented safety data are not available for doses above 80 mg daily for periods longer than 2 weeks. Adults-Intramuscular Injection. NOT FOR INTRAVENOUS USE. The intramuscular dosage form is to be used temporarily when the patient cannot take oral medication. Intramuscular injection is about twice as bioavailable as oral dosage forms; consequently, the recommended intramuscular dose is 80 mg daily (in 4 equally divided doses). Oral dicyclomine hydrochloride should be started as soon as possible and the intramuscular form should not be used for periods longer than 1 or 2 days.

Dicyclomine showed inhibitory action against several pathogenic bacteria. Dicyclomine inhibited most of the bacterial isolates tested at 25-100 microg/ml concentration, and a few were sensitive even at a lower concentration (10 microg/ml). Dicyclomine was found to be bacteriostatic in nature against Shigella dysenteriae 7, and bactericidal against S. aureus NCTC 6571, 8530, and 8531.