Bisulfite-Containing Propofol: Is it a Cost-Effective Alternative to Diprivan™ for Induction of Anesthesia? Xinli Shao, MD, PhD, Hong Li, MD, Paul F. White, PhD, MD, FANZCA, Kevin W. Klein, MD, Christine Kulstad, MS, and Andrew Owens, MS Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas Propofol (Diprivan™; AstraZeneca, Wilmington, DE) is a commonly used drug for the induction of general anesthesia in the ambulatory setting. With the availabil- ity of a new bisulfite-containing generic formulation of propofol, questions have arisen regarding its cost effec- tiveness and safety compared with Diprivan™. Two hundred healthy outpatients were randomly assigned, according to a double-blinded protocol, to receive either Diprivan™ or bisulfite-containing propofol 1.5 mg/kg IV as part of a standardized induction sequence. Mainte- nance of anesthesia consisted of either desflurane (4%– 8% end-tidal) or sevoflurane (1%–2% end-tidal) in combina- tion with a remifentanil infusion (0.125 g  kg -1  min -1 IV). Patient assessments included pain on injection, induc- tion time, hemodynamic and bispectral electroencephalo- graphic changes during induction, emergence time, and incidence of postoperative nausea and vomiting. The two propofol groups were comparable demographically, and the induction times and bispectral index values during the induction were also similar. However, the bisulfite- containing formulation was associated with less severe pain on injection (5% vs 11%), with fewer patients recall- ing pain on injection after surgery (38% vs 51%, P  0.05). None of the patients manifested allergic-type reactions af- ter the induction of anesthesia. The acquisition cost (aver- age wholesale price in US dollars) of a 20-mL ampoule of Diprivan™ was $15 compared with $13 for the bisulfite- containing propofol formulation. Therefore, we con- cluded that the bisulfite-containing formulation of propo- fol is a cost-effective alternative to Diprivan™ for the induction of outpatient anesthesia. (Anesth Analg 2000;91:871–5) T he original preparation of propofol was formu- lated as a 1% solution in 16% polyoxyethylated castor oil. This formulation had to be withdrawn from clinical testing because its use was associated with an unacceptably frequent incidence of anaphy- lactic reactions (1,2). The subsequent commercial preparation of propofol (Diprivan™; AstraZeneca, Wilmington, DE) was formulated in a fat emulsion consisting of 10% soybean oil containing long-chain triglycerides, and EDTA was added as a preservative. Although this preparation has gained widespread popularity in clinical practice, its use is associated with a greater incidence of pain on injection (3,4). Moderate-to-severe pain on injection of Diprivan™ has been reported in 32%– 67% of patients receiving a standard bolus dose for the induction of anesthesia (5). It has been proposed that the solvent can influence the incidence of pain on injection of propofol (6,7). For example, changing the composition of the carrier fat emulsion influenced the incidence of pain on injection without altering the pharmacokinetic or dynamic properties of this IV anesthetic (7). The recently ap- proved generic formulation of propofol (Baxter PPI, Liberty Corners, NJ) has a pH of 6.4 and contains sodium metabisulfite as a preservative. Its safety and efficacy has not been directly compared with the cur- rent “gold standard,” namely Diprivan™. The objective of this study was to compare the hypnotic properties and side effect profile of this new bisulfite-containing propofol formulation with those of Diprivan™ when used for the induction of anesthe- sia. This prospective, randomized, double-blinded in- vestigation tested the hypothesis that an equivalent dose of bisulfite-containing propofol would be associ- ated with less pain on injection than Diprivan™. Methods After we obtained institutional review board approval at University of Texas Southwestern Medical Center in Accepted for publication May 5, 2000. Address correspondence to Paul F. White, PhD, MD, Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75235-9068. Address e-mail to paul.white@utsouthwestern.edu. ©2000 by the International Anesthesia Research Society 0003-2999/00 Anesth Analg 2000;91:871–5 871