RIMSO-50 ® (dimethyl sulfoxide) (DMSO) 50% w/w Aqueous Solution for intravesical instillation. Each mL contains 0.54 gm dimethyl sulfoxide STERILE AND NON-PYROGENIC. Intravesical instillation for the treatment of interstitial cystitis. NOT FOR INTRAMUSCULAR OR INTRAVENOUS INJECTION. The active component of RIMSO-50 ® is dimethyl sulfoxide which has the empirical formula C 2 H 6 OS, and is structurally represented as: Dimethyl sulfoxide is a clear, colorless and essentially odorless liquid which is miscible with water and most organic solvents. Other physical characteristics include: molecular weight 78.13, melting point 18.3° C, and a specific gravity of 1.096. Chemical Structure

RIMSO-50 ® (dimethyl sulfoxide) is indicated for the symptomatic relief of patients with interstitial cystitis. RIMSO-50 ® has not been approved as being safe and effective for any other indication. There is no clinical evidence of effectiveness of dimethyl sulfoxide in the treatment of bacterial infections of the urinary tract.

Instillation of 50 mL of RIMSO-50 ® (dimethyl sulfoxide) directly into the bladder may be accomplished by catheter or asepto syringe and allow to remain for 15 minutes. Application of an analgesic lubricant gel such as lidocaine jelly to the urethra is suggested prior to insertion of the catheter to avoid spasm. The medication is expelled by spontaneous voiding. It is recommended that the treatment be repeated every two weeks until maximum symptomatic relief is obtained. Thereafter, time intervals between therapy may be increased appropriately. Administration of oral analgesic medication or suppositories containing belladonna and opium prior to the instillation of RIMSO-50 ® can reduce bladder spasm. In patients with severe interstitial cystitis with very sensitive bladders, the initial treatment, and possibly the second and third (depending on patient response) should be done under anesthesia. (Saddle block has been suggested).

Dimethyl sulfoxide can initiate the liberation of histamine and there has been occasional hypersensitivity reaction with topical administration of dimethyl sulfoxide. This hypersensitivity has been reported in one patients receiving intravesical RIMSO-50 ® . The physician should be cognizant of this possibility in prescribing RIMSO-50 ® . If anaphylactoid symptoms develop, appropriate therapy should be instituted.