Product Monograph - Rimso-50
ADVERSE REACTIONS
A garlic-like taste may be noted by the patient within a few minutes after instillation of RIMSO-50 (dimethyl sulfoxide). This taste may last several hours and because of the presence of metabolites, an odor on the breath and skin may remain for 72 hours. Transient chemical cystitis has been noted following instillation of 100% dimethyl sulfoxide.
The patient may experience moderately severe discomfort on administration. Usually this becomes less prominent with repeated administration.
PHARMACOLOGY
Dimethyl sulfoxide in some lower animals, including rabbits, dogs and pigs has been shown to produce changes in the refractive index of the lens of their eye. The oral route appears more likely to cause such ocular changes which occur at doses of 1 g/kg/day of dimethyl sulfoxide for treatment periods as short as 69 days. The rabbit was the most susceptible of the species treated while the rheus monkey was most resistant.
Dimethyl sulfoxide has a wide spectrum of primary pharmacologic activity, including:
- a) Membrane penetrant
- b) Solute “carrier” across membranes
- c) Anti-inflammatory
- d) Analgesia
- e) Diuresis
- f) Cholinesterase inhibitor
- g) Muscle relaxation
- h) Vasodilation
TOXICITY
A refractive index change in the lens (not an opacity) had been observed after 3 months at a dose of approximately 5 g/kg in dogs, rabbits and pigs. No microscopic or chemical differences could be found between the lenses of the treated animals and the controls. In the affected animals, there appeared two distinct zones of different refraction. This could easily be observed with an opthalmoscope and with a slit lamp. It appeared to be a dose-related effect, and it diminished as the dose was reduced. It is noteworthy that the effect was produced 50 to 100 times the usual human therapeutic dose.
Extensive toxicology studies have been conducted in numerous animal species, at 3 to 30 times the dose anticipated for humans, for periods of up to 18 months. Dimethyl sulfoxide appears to be a relatively safe drug for human administration and the lens changes which have been noted in animals have not yet been reported in humans.
DOSAGE AND ADMINISTRATION
Instillation of 50 mL of RIMSO-50 (dimethyl sulfoxide) directly into the bladder may be accomplished by catheter or asepto syringe and allowed 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. In selected cases where symptomatic relief is not complete, the bladder may be gently distended by gravity instillation with up to 500 mL of a solution prepared immediately prior to instillation in a glass vial, with one part RIMSO-50 and one part sterile water prior to the instillation of the standard dose of 50 mL of RIMSO-50. After retention of RIMSO-50 for 15 minutes the medication is again expelled by spontaneous voiding. Administration of oral analgesic medication or suppositories containing belladonna and opium prior to the instillation of RIMSO-50 can reduce bladder spasm in particularly sensitive patients. In patients with very sensitive bladders, the initial treatment should be done under anesthesia (preferable saddle block type).
RIMSO-50 is recommended for bladder instillation only.
DOSAGE FORMS
Bottles contain 50 mL (54 gm) of sterile and pyrogen-free RIMSO-50 (50% w/w dimethyl sulfoxide aqueous solution).
STORAGE CONDITIONS
RIMSO-50 (50% w/w dimethyl sulfoxide aqueous solution) should be stored between 15° and 30°C and protected from light.
RIMSO-50 is manufactured by Mylan Pharmaceuticals ULC. For more information please call the customer service line at 1-800-575-1379.
