Bacteriostatic Water

What Is Bacteriostatic Water?

Think of a patient in a hospital bed, clear tubes hooked up to their arm. You've probably seen the familiar clear liquid that runs through these tubes. Hospitals inject patients with all sorts of life-sustaining fluids, from saline for rehydration, to glucose to manage blood sugar levels. These clear fluids can be found hanging from bags by a patient's bedside.

Bacteriostatic water is water that has been made to inhibit the growth of most types of bacteria. It is comprised of sterile and filtered water, with all bacteria removed, which is then mixed with 0.9% benzyl alcohol, which prevents any contaminating bacteria from growing in the water. In this way, the water has become 'static', or relatively unchanging in its bacterial content.

Bacteriostatic water is used to dilute or dissolve medications for patient injection. It is different from sterile water, which is filtered and purified but has no additives, and is usually only available for single-use.

Why Use Bacteriostatic Water?

Bacteriostatic water can be injected in three main ways:

•         Intravenous injection is performed by accessing a vein with a needle.
•        Intramuscular injection accesses a muscle with a needle.
•        Subcutaneous injection means under the skin, with the root sub- meaning beneath, and cutaneous pertaining to the skin.

You might ask yourself, why doesn't bacteriostatic water just use an agent that kills bacteria outright? It's true, bacteriostatic water doesn't contain an anti-bacterial agent like some other fluids for injection, so it doesn't kill bacteria off - it just prevents bacteria from growing in the water. But anti-bacterial agents can have adverse reactions to medications, while benzyl alcohol doesn't. Therefore, bacteriostatic water can be used for a broader array of drug dilutions or injections without negatively interacting with bacteria-destroying additives.