Drug Interactions between Effervescent Pain Relief and treosulfan

MONITOR: Agents that cause urinary alkalinization can reduce serum salicylate concentrations in patients receiving anti-inflammatory dosages of aspirin or other salicylates. The mechanism involves reduction in salicylate renal tubular reabsorption due to increased urinary pH, resulting in increased renal salicylate clearance especially above urine pH of 7. This interaction is sometimes exploited in the treatment of salicylate toxicity.

MANAGEMENT: Patients treated chronically with urinary alkalinizers and large doses of salicylates (i.e. 3 g/day or more) should be monitored for potentially diminished or inadequate analgesic and anti-inflammatory effects, and the salicylate dosage adjusted if necessary.

MONITOR: Parenteral hydration with sodium bicarbonate during treosulfan infusion has been related to an increase of skin disorders like rash and dermatitis. The mechanism of the interaction may be acceleration of the pH-dependent formation of alkylating epoxides. Also, this combination may induce bladder injury from activation of treosulfan in alkaline urine.

MANAGEMENT: Caution is advised when parenteral sodium bicarbonate is used during treosulfan infusion. Patients should be monitored for increased skin disorders such as rash and dermatitis, and for bladder injury. Some experts discourage the alkalinization of patients during treatment with treosulfan and recommend a split-dose or continuous IV infusion regimen of high-dose treosulfan to avoid risk of methanesulfonic acid induced acidosis.