The number of available IV medications continues to expand. Many hospitals have experienced increases in patient acuity and a rise in the number of medications administered to each patient. This increases the likelihood that multiple IV medications will need to be administered concurrently. Separate IV access sites for drug administration are not always practical, and an increase in the number of sites can increase the risk for infectious complications.

These factors contribute to the escalating complexity of IV drug administration and have resulted in an ever-expanding number of possible incompatibilities.The potential for serious and life-threatening adverse drug events exists when incompatible medications are infused together. Therefore, it is important to verify drug compatibility before coadministration. A clear and concise compatibility chart can be a useful tool to help deliver safe, high-quality IV therapy to patients; in some settings, it is considered a preferred reference source due to ease of use.

A chance of incompatibility exists whenever any IV medication is combined with another. A change in pH is the primary characteristic involved in drug incompatibilities. However, compatibility depends on many factors including concentration, temperature, storage vehicle, order of mixing, and administration technique. Incompatibility also can be caused by excipients in a medication.

Three types of incompatibilities are commonly discussed: physical, chemical, and therapeutic. Physical incompatibilities are the most easily detected and are evidenced by visible changes, such as particulate formation, haze, precipitation, color change, and gas evolution. Chemical incompatibilities are those that result in decomposition of a drug. Loss of potency of greater than 10% over the defined testing period is considered chemical incompatibility. Most chemical incompatibilities can be detected only with a suitable analytical method. Therapeutic incompatibilities, in which a drug combination results in undesirable antagonistic or synergistic pharmacologic activity, are beyond the scope of most compatibility references.

The purpose of this chart is to provide concise, easily accessible, Y-site compatibility data. Although there are differing types of incompatibilities, the type of incompatibility or compatibility is not specified in this chart. A designation of “compatible” indicates that the combination evaluated appears to be compatible based on the tests performed, whether these tests measured physical, chemical, or both types of compatibility. All conditions that may affect compatibility cannot be included in such a format, and it is not possible to predict all incompatibilities that may arise, but it is hoped that the information provided may help clinicians minimize their occurrence. Continuing research adding to the existing body of knowledge on IV compatibilities is vital.