Omniscan was created as a contrast agent for use in Magnetic Resonance Imaging (MRI) procedures and was approved for use by the US Food and Drug Administration in 1993. Also known as Gadodiamide, the agent is considered a paramagnetic agent that tends to generate a localized magnetic field. When protons move through this field, the protons are reorganized in such a way as to provide highly detailed images of the body. The contrast agent can be used for both adults and children and comes in a variety of different sizes for use in the most commonly performed procedures. Packaging Omniscan in different sizes reduces the risk of a physician administering a wrong dosage through confusion of the dosing instructions.
Omniscan is commonly used for producing detailed images of the central nervous system, showing any lesions or tumors that are present. It is also used for the imaging of the chest, abdominal, and pelvic cavities as well as the musculoskeletal system. The contrast agent is administered by IV or injection directly into the blood stream. After allowing the contrast agent to circulate through the system for roughly 45 minutes, the MRI is performed and the images are taken. Omniscan is eliminated from the body by the kidneys through the urine within 24 hours of the administration of the dose, too quickly for the agent to decompose within the body causing a toxic reaction.
The most common side effects resulting from the use of Omniscan include headache, dizziness, and nausea, occurring in around 3% of patients during clinical trials. Some individuals have also experienced an allergic reaction occurring at the site of the injection, causing swelling, rash, and/or pain at the injection site. Other side effects experienced by patients who have taken Omniscan include fatigue, chest pain, fever, flushing, diarrhea, abdominal pain, and increased anxiety.
There is a possibility that a patient that has taken Omniscan may experience a serious adverse allergic reaction to the agent which will require emergency medical treatment to avoid numerous complications and/or death. Omniscan should not be administered to any patient suspected of being sensitive to its components. Any patient who has a history of drug reactions or known allergic reactions should be observed carefully to ensure that their health has not been compromised. Extreme caution should also be taken when administering Omniscan to patients with impaired renal function. Because the contrast agent is eliminated by the kidneys, any patient with impaired renal function may not be able to eliminate the agent from the body quickly enough to avoid serious complications.
Recent studies has linked Omniscan, along with other approved contrast agents containing Gadolinium, to a very serious, debilitating condition known as Nephrogenic Systemic Fibrosis. This condition only affects individuals with moderate to severe renal impairment or renal failure that have taken Omniscan or other FDA approved contrast agents containing Gadolinium prior to undergoing an MRI. The condition is characterized by the tightening and hardening of areas of the skin located on the extremities of the body. Eventually, the areas of affected skin begin to resemble an orange peel and restrict the movement of the joints and muscles beneath the areas of affected skin. There is no cure for the condition and an effective treatment has yet to be found.