Drug delivery systems: Multiple- vs. single-dose

Key Points

All hospitals and health systems must decide whether to use multiple-dose vials (MDV) or single-dose vials (SDV) of drugs, a decision that usually rests on two considerations: Cost reduction and patient safety.

Business case: MDVs vs. SDVs

Healthcare systems often justify the use of injectable medications in multiple-dose containers as economical; cost per dose and storage costs are generally less for MDVs than for SDVs. However, the overall cost of delivering injectable medication is much more difficult to evaluate, because it can include the cost of treating cross-contaminated patients or those who have contracted a nosocomial infection secondary to MDV use and wastage.

In calendar year 2008, the U.S. Department of Veterans Affairs (VA) anticipated using more than four million MDVs, which represented a potential of 2,000 new MDV-related nosocomial infections. The cost to treat these cases is substantial. Press Ganey reported that the average cost of treating a nosocomial infection is $13,973.² Use of MDVs potentially increases annual VA healthcare costs by approximately $28 million.

Another cost-related factor is wasted medication. In a VA study by Sheth et al., in 90 percent of MDVs evaluated, 25 percent or less of the original volume was used before the vial's expiration date.³ Including the cost of drug waste, the cost per dose delivered was 86 percent higher than the product's SDV cost.

When cross-contamination and waste are considered, an SDV may be the most cost-effective alternative.

MDV vs. SDV: Which is safer?

Common misconceptions about MDVs and SDVs include the following:

USP defines MDVs as multiple-unit containers (such as vials) for articles or preparations for parenteral administration only. MDVs usually contain antimicrobial preservatives, which permit removal of portions on multiple occasions.

USP defines SDVs as single-unit containers for articles or preparations intended for parenteral administration, such as prefilled syringes, cartridges, fusion-sealed containers, and closure-sealed containers, when so labeled. The USP notes: "Opened or needle-punctured single-dose containers such as ampoules, bags, bottles, syringes, and vials of sterile products ... shall be used within 1 hour if opened in worse than ISO Class 5 (pharmacy IV room) air quality and any remaining contents must be discarded. Opened single-dose ampoules shall not be stored for any time period."⁴

Recommended actions

What can be done to enhance the safe delivery of injectable medications?

References

1. Centers for Disease Control and Prevention. Guideline for prevention of intravascular device-related infections. Part I. Intravascular device-related infections: An overview. The Hospital Infection Control Practices Advisory Committee. Am J Infect Control. 1996;24:262-277.

2. Press Ganey. Press Ganey knowledge summary: The cost of nosocomial infections. http://www.pressganey.com/files/nosocomial_infections_cost.pdf. Accessed October 8, 2009.

3. Sheth, NK, Post, GT, Wisnieski, TR, Uttech, BV. Multidose vials versus single-dose vials: A study in sterility and cost effectiveness. J Clin Microbiol. 1983;17: 377-379.

4. U.S. Pharmacopeia. http://www.usp797.org/index.html. Accessed October 8, 2009.

5. Lehmann C, Reed B. Refrigeration of used multidose vials. Am J Hosp Pharm. 1993;50:1138.

Keith W. Trettin, RPh, MBA,is a program manager with the VA National Center for Patient Safety.