90:28.08.92 Antimetabolites, Immunosuppressive Therapy, Miscellaneous
Generic Name
Azathioprine sodium is available as a lyophilized powder in 20-mL vials containing the equivalent of 100 mg of azathioprine with sodium hydroxide and/or hydrochloric acid to adjust the pH.3979 Reconstitute each vial by adding 10 mL of sterile water for injection and swirling until a clear solution results.3979
pH
The reconstituted solution has a pH of approximately 9.6.3979
Trade Name(s)
Imuran
Azathioprine sodium is administered intravenously.3979 The manufacturer states reconstituted solutions of azathioprine sodium are usually diluted in sterile saline or dextrose for infusion to a final volume that depends on the infusion time.3979 Infusions are usually administered over 30 to 60 minutes but have been given over 5 minutes or up 8 hours.3979
In the event of spills or leaks, a manufacturer has recommended sodium hypochlorite 5% (household bleach) and sodium hydroxide (concentration unspecified) to inactivate azathioprine.1200
Azathioprine sodium is a yellow powder.3979 Intact vials should be stored at controlled room temperature in the original carton and protected from light.3979 It is stated to be stable in neutral or acid solutions but is hydrolyzed to mercaptopurine in alkaline solutions, especially on warming.3979 Maximum stability occurs at pH 5.5 to 6.5.1633 Hydrolysis to mercaptopurine also occurs in the presence of sulfhydryl compounds such as cysteine, glutathione, or hydrogen sulfide.3979
Reconstituted solutions of azathioprine sodium should be used within 24 hours after reconstitution.3979 A 10-mg/mL aqueous solution is stated to be stable for 24 hours at 15 to 25°C.3979 Azathioprine sodium is stated to be incompatible with methylparaben, propylparaben, and phenol.108
Storage of the reconstituted solution in the original vial and in plastic syringes (Jelco) at 20 to 25°C under fluorescent light resulted in no decomposition or precipitation in 16 days. At 4°C in the dark, a visible precipitate formed after four days.605
Azathioprine sodium (Burroughs Wellcome) 100 mg/50 mL diluted in dextrose 5%, sodium chloride 0.9%, or sodium chloride 0.45% in PVC bags (Travenol) was stored at 20 to 25°C under fluorescent light and at 4°C in the dark. No decomposition occurred in the solutions over 16 days of storage. However, a precipitate formed in the dextrose 5% admixtures by the 16th day. No precipitate was observed after eight days of storage.605
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