Undesirable adverse reactions are usually mild or moderate, reversible and infrequent.
Most adverse reactions develop within the first minutes after the administration of the drug.
General types of reactions
The most common headache, pain at the injection site, generalized feeling of heat, increased sweating, a sense of metallic taste in the mouth.
Much less likely to be a feeling of discomfort or pain in the abdomen, nausea, vomiting.
Hypersensitivity reactions
Usually it can be such skin or respiratory reactions as various types of rash, erythema, urticaria, itching, pale skin; acute rhinitis, edema of the larynx, dyspnea and a moderate decrease in blood pressure. These effects are usually short-lived.
Very rarely there is dizziness, stiff neck, low back pain, temporary confusion. In some cases, fever occurs.
Possible individual hypersensitivity, especially pronounced the persons with a predisposition to allergies, and also taking beta-blockers. In cases of hypersensitivity reactions, the administration of contrast medium should be immediatelydiscontinued and, if necessary, an appropriate emergency intravenous therapy.
Severe cases of anaphylaxis involving the cardiovascular system are extremely rare and include the development of peripheral vasodilation with significant lowering of arterial pressure, reflex tachycardia, shortness of breath, agitation, cyanosis, loss of consciousness following a respiratory and / or heart attack, which can lead to death. Since these phenomena can develop very quickly, they require urgent cardiopulmonary resuscitation. Initially, cardiovascular collapse may occur, isolated or as an initial manifestation without respiratory or other symptoms listed above.
From the side of the cardiovascular system: peripheral vasodilation, marked decrease in blood pressure, tachycardia, shortness of breath, agitation, cyanosis and loss of consciousness (may require urgent treatment), transient bradycardia.
From the nervous system: tonic / clonic convulsions, aphasia, syncope, temporary narrowing of the visual fields, hemiparesis, coma (developed in patients suffering from diseases of the central nervous system).In some cases, patients with increased convulsive readiness or using psychotropic drugs, with the introduction of the drug may cause spasms of skeletal muscles or generalized convulsions.
General measures to prevent adverse reactions
- to identify patients at risk (patients with dehydration, impaired renal function, diabetes mellitus, severe cardiovascular failure, patients with adverse reactions to the introduction of iodinated radiopaque substance in history, children under one year old, patients older than 70 years, patients, using nephrotoxic drugs (NSAIDs, loop diuretics, ACE inhibitors (enalapril, captopril and others), aminoglycosides, platinum compounds, methotrexate in high dosages, pentamidine, sodium foscarnet, some antiviral agents (acyclovir, ganciclovir, valaciclovir, adefovir, cidofovir, tenofovir); vancomycin, amphotericin B; immunosuppressants, such as ciclosporin or tacrolimus; and phosphamide, etc.);
- provide sufficient hydration orally or, if necessary, by intravenous infusion (every hour for ≥ 100 ml orally or intravenously (0.9% solution of sodium chloride, sodium hydrogen carbonate) within 4 hours before and 24 after the administration of the radiopaque preparation, depending on the patient's condition);
- avoid simultaneous use of nephrotoxic drugs; if such a combination is necessary, monitoring of renal function should be strengthened;
- to observe the interval not less than 48 hours between two radiological examinations with the introduction of radiopaque preparation or postpone a new examination until the restoration of the initial renal function;
- PReducing acidosis with increasing lactate concentration in patients with diabetes mellitus taking metformin, based on the data of creatininemia. Normal renal function: the administration of metformin is stopped at least 48 hours before the introduction of the radiopaque preparation or until the normal renal function is restored. Abnormal renal function: metformin is contraindicated. For urgent indications: if the examination is urgently needed, the following precautions should be taken: discontinuation of metformin intake, hydration, monitoring of renal function and the search for signs of acidosis with increasing lactate concentration.Patients on hemodialysis can take iodinated radiopaque substances, since they are amenable to dialysis. It is necessary to take a preliminary conclusion from the hemodialysis department;
- after the introduction of the radiopaque preparation, it is necessary to observe the patient for at least 30 minutes, since the majority of serious side effects occur during this period;
- the patient should be warned about the possibility of delayed-type reactions (up to 7 days).
Adverse reactions and warnings in neuroradiogenological studies
In the case of cerebrospinal blockade when the drug is administered, as much as possible of the injected contrast solution should be removed.
In cases of the presence of blood in the cerebrospinal fluid, the physician should carefully evaluate the necessary need for a diagnostic procedure taking into account the risk to the patient.
The appointment of myelography to patients with a risk of epilepsy, history of epilepsy or severe renal and hepatic impairment should be carefully weighed. Patients taking anticonvulsant drugs should not interrupt their treatment.Manipulation with the patient during and after the examination should be minimal. After examination, the patient should remain in a supine position, with a raised head, for at least 8 hours. Observation of the patient should be especially attentive within 24 hours, at this time the patient is advised not to bend over.
Adverse reactions and warnings in angiographic studies
In patients undergoing angiocardiographic procedures, special attention should be given to the state of the right heart and pulmonary circulation. The introduction of an organic iodine-containing solution in the absence of right heart and pulmonary hypertension can cause bradycardia and lowering blood pressure. Increased caution should be observed when introducing a contrast agent in the right heart cavity of newborns with pulmonary hypertension and impaired cardiac function.
When contrasting the arch of the aorta in a number of cases, it is possible to develop a decrease in blood pressure, bradycardia.
With abdominal aortography, kidney infarction, damage to the spinal cord, retroperitoneal bleeding, and bowel necrosis may occur.
With peripheral arteriography with a drug at a dosage of 350 mg / ml, pain in the examined extremity may sometimes occur. Usually this is not observed when using a less concentrated solution - 300 mg / ml.
When vessels are catheterized, special attention should be given to angiographic techniques, since non-ionic contrast agents, in comparison with ionic contrast agents, have a lower anticoagulant activity in vitro. In this regard, to minimize the risk of thromboembolism associated with the procedure, it is necessary to properly install the catheter, wash it with saline, if possible with the addition of heparin, and also minimize the duration of the procedure.