Unsafe injection practices can cause infectious disease in individual patients and may also lead to outbreaks within a facility. In 2015-2016, the Australian Commission on Safety and Quality in Health Care reported that hospital-acquired infections affected one in 74 hospitalisations in the public sector. Hospital-acquired infections have a significant impact on patient morbidity and mortality, as well as healthcare costs. A patient’s mortality risk is thought to be at least three times higher if they acquire an infection in hospital.

Infections related to the contamination of vials and ampoules can include life-threatening conditions such as bloodstream infections, meningitis, and epidural abscesses. Ampoules and vials can be classified as either ‘multi-dose’ or ‘single-dose’. A multi-dose vial contains more than one dose of medication and is formulated with an antimicrobial preservative. Conversely, a single-dose vial is typically formulated without a preservative and is intended for use in a single patient on a single occasion.

Single-dose vials

Preservative-free preparations can easily become contaminated. If a single-dose vial is contaminated and then reused for more than one patient, the result may be an outbreak in multiple patients rather than just a single case of hospital-acquired infection. However, it is worth noting that the preservatives used in parenteral products do not offer sufficient protection against non-bacterial pathogens such as viruses, protozoa, and prions. For this reason, it is imperative that strict aseptic technique is practised for all injections regardless of whether the product contains a preservative or not.

Single-dose vials or pre-filled syringes are preferred to multi-dose vials to reduce the risks associated with microbial contamination. While single-dose products are considered safer, this is only true if they are used in accordance with best practice. Best practice dictates that a single-dose vial is only entered once and any unused contents discarded immediately afterwards. If multiple entries into a single-dose vial are considered appropriate by the healthcare professional, it must only occur if allowed under hospital policy.

In this current environment, drug shortages may also present an issue. When a critical medicine is in short supply, the concept of drug wastage may assume increased significance. However, the inappropriate reuse of single-dose vials can create additional problems. A long-term drug shortage of bupivacaine was determined to be a factor in an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in the United States. Clinic staff reused single-dose vials for multiple patients in an attempt to conserve their limited stock. Many of these patients developed infections with an identical strain of MRSA that required hospitalisation, antibiotic therapy, and debridement. In the case of a critical drug shortage, hospital policy will determine the most appropriate course of action.

There is one circumstance where the reuse of single-dose vials is deemed acceptable by the Therapeutic Goods Administration (TGA). However, for these purposes, the manipulation of the dose form is considered pharmaceutical compounding. These processes should occur under unidirectional airflow (Grade A environment) in compliance with Good Manufacturing Practice, i.e. the TGA guidelines are not applicable for use in the ward environment.

Multi-dose vials

While single-dose products are generally preferred, there may be cases where an injectable product is only available in a multi-dose vial. The National Health and Medical Research Guidelines advocate the following steps to reduce the risk of infectious disease transmission when using multi-dose vials:

  • Restrict the vial to single patient use wherever possible;
  • Establish a separate secure area designated for the placement of these medications away from any work area;
  • Strict compliance with the manufacturer’s recommendations regarding storage, use within a specified time, and expiry date. Some preservatives are actually less effective at lower temperatures, so refrigeration is not recommended for all products;
  • Use a sterile needle and syringe to draw up the required dose from the vial or ampoule on every occasion;
  • Use a sterile needle to draw up all the contents of the container into individual syringes before administering to patients;
  • Only store the current patient’s medication in the immediate working environment
  • Discard any open ampoule(s) at the end of each procedure; and
  • Discard product if product sterility or integrity is compromised or questionable.


Microbial contamination can occur during the preparation and administration of any medicine from a multi-dose or single-dose vial. Therefore, strict attention to aseptic technique is essential whenever a medication is prepared or administered parenterally. It is recommended that medication vials and ampoules be discarded if sterility is compromised or cannot be confirmed.


  1. Australian Commission on Safety and Quality in Health Care. Hospital-Acquired Complication 3: Healthcare-associated Infections. Sydney: ACSQHC; 2018.
  2. Australian Government. Australian Guidelines for the Prevention and Control of Infection in Healthcare. Canberra: National Health and Medical Research Council; 2019.
  3. Bongaerts GP, Jansen LE. Why refrigeration paradoxically prolongs bacterial survival in the presence of preservatives. Clin Infect Dis. 2003; 37(10): 1403.
  4. Department of Health. Compounded medicines and good manufacturing practice (GMP). Woden: Therapeutic Goods Administration; 2017.
  5. Stokowski LA. Single-use vials: safety, cost, and availability. Medscape; 2012.

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