Drug Interactions between asparaginase escherichia coli and DDAVP

MONITOR: Concomitant use of asparaginase with other hepatotoxic agents may potentiate the risk of liver injury. Asparaginase-associated hepatotoxicity has been reported more commonly in adults than in children and has been strongly associated with obesity. Hepatomegaly, acute severe hepatotoxicity, and fatal liver failure have been reported with asparaginase treatment in adults. Also, asparaginase may increase the toxicity of drugs bound to plasma proteins or metabolized by the liver.

MANAGEMENT: The risk of additive hepatotoxicity should be considered when asparaginase is used with other hepatotoxic agents (e.g., alcohol, androgens, antituberculosis agents, azole antifungal agents, ACE inhibitors, macrolide antibiotics, nonsteroidal anti-inflammatory agents, nucleoside reverse transcriptase inhibitors, sulfonamides, thiazolidinediones, and statins). Liver function tests should be monitored at regular intervals during asparaginase treatment with or without other hepatotoxic drugs. Patients should be advised to seek medical attention if they experience potential symptoms of hepatotoxicity such as right upper quadrant pain, increasing abdominal size, fever, rash, itching, anorexia, nausea, vomiting, fatigue, malaise, dark urine, pale stools, and jaundice.

Food may decrease the rate and extent of absorption of desmopressin following oral administration. In 16 healthy, nonsmoking volunteers, administration of a single 400 mcg oral dose of desmopressin concomitantly with a standardized meal (27% fat) resulted in a 52% decrease in the peak plasma concentration (Cmax) of desmopressin and a 43% decrease in systemic exposure (AUC) compared to administration in the fasting state. The Cmax and AUC were still reduced by 46% and 41%, respectively, when desmopressin was administered 1.5 hours after eating. Both feeding regimens prolonged the time to reach peak plasma concentration (Tmax) from 1 hour to 1.5 hours. However, the pharmacodynamic effects of desmopressin were not affected as assessed by urine volume and osmolality for at least 4 hours postdose. The degree of antidiuresis was similar in the absence of food and when the drug was taken with or 1.5 hours after eating. These findings would suggest a fairly minor clinical impact of the interaction in most patients, especially since oral desmopressin is intended for administration at bedtime. Nevertheless, the possibility of food effects should be considered before increasing the dose whenever a diminution of effect is noted. A significant interaction is not expected to occur with the sublingual formulation, since absorption occurs primarily in the oral mucosa, pharynx, and esophagus.