Side effects
As a rule, contrast media are well tolerated by patients. Nevertheless, contrast media containing iodine (used in CT and X-rays) in particular can cause very rare but extremely serious side effects. During the intravenous injection of contrast media containing iodine, many patients feel a relatively immediate sensation of warmth, a metallic taste on the tongue or an urge to urinate.
In most cases, these phenomena are harmless and disappear again after a short time. More severe reactions occur within the first 20-30 or 3-5 minutes and can be divided into four stages: However, the medical staff is usually optimally prepared for described reactions, so that fast and effective therapeutic measures can be initiated quickly. Due to the remaining residual risk, patients must be informed by a physician about possible complications before each administration of contrast medium and confirm this in writing.
In summary, however, modern contrast media containing iodine are very well tolerated, and severe side effects are extremely rare. Side effects caused by MRI contrast media can only be observed in extremely rare cases, but can be just as life-threatening.Due to previously unknown mechanisms, affected persons suffer from nausea, vomiting, wheals with itching, shortness of breath, dizziness, trembling, etc.
- Stage: skin reactions (e.g. wheals, itching) and mild general symptoms (e.g. nausea, sweating)
- Stage: Severe gastrointestinal symptoms (e.g. nausea, vomiting) and circulation problems
- Stage: Anaphylactic shock with shortness of breath, severe wheals, etc.
- Stage: Anaphylactic shock with respiratory arrest
Known contrast agent allergy – what now?
Sometimes an imaging has to be performed despite an allergy to contrast media. With appropriate preparation, e.g. intravenous administration of antiallergics and cortisone preparations, an allergic reaction can be largely prevented. Therefore, it is absolutely necessary to report previously experienced complications due to contrast medium!
Thyroid gland
Our thyroid gland needs the trace element iodine for the production of vital thyroid hormones. Since most X-ray or CT contrast media contain iodine, the thyroid gland values must be kept in view before an examination! Your treating physician will determine the corresponding hormones in the blood (fT3, fT4, basal TSH).
If you suffer from a known hyperthyroidism or active thyroid nodules, special caution is required. This is because the contrast media supply our body with high amounts of iodine within a short time. As a result, our thyroid gland is “stimulated” to increase its hormone production. In the case of an already existing hyperactivity, the thyroid gland is overactive anyway, so that additional stimulation can lead to a sometimes dangerous increase in hormones. Sometimes even an overactive thyroid gland can be triggered by contrast media containing iodine.
