Recommended precautions when using low-osmolality or nonionic contrast agents with vasodilators

Low-osmolality contrast agents were tested for potential chemical incompatibility with vasodilators commonly used in angiography. A mixture of Hexabrix and papaverine produced a white crystalline precipitate. Hexabrix and tolazoline exhibited transient immiscibility. Injection of a flush solution between vasodilator and contrast agent is recommended as a precaution.