Diabetes. Caution is prescribed to patients with diabetes mellitus, since beta-blockers may mask the symptoms of acute hypoglycemia.
Thyrotoxicosis. With caution appoint the drug to patients with thyrotoxicosis, tk. beta-blockers may mask the symptoms of thyrotoxicosis (eg, tachycardia). Patients with suspected thyrotoxicosis should not abstain from beta-blockers, this can cause an increase in symptoms.
Myasthenia gravis. It should be borne in mind that beta-blockers can cause symptoms similar to those in myasthenia gravis (diplopia, ptosis, general weakness).
Pulmonology. Caution should be given to beta-blockers in patients with severe impairment of the function of the respiratory system. Despite the fact that in clinical studies the absence of betaxolol in the ophthalmic dosage form on the function of external respiration has been shown, it is impossible to exclude the possibility of hypersensitivity to the drug.
Surgery. Before the planned surgery, you should gradually cancel the beta-blockers 48 hours before the general anesthesia, tk. during general anesthesia, they can reduce the sensitivity of the myocardium to sympathetic stimulation.
The risk of developing an anaphylactic reaction. Patients who use beta-blockers may have a history of atopy or anaphylactic reactions. In the case of the development of repeated reactions of hypersensitivity, such patients may not be sensitive to the usual doses of epinephrine (adrenaline) necessary for arresting anaphylaxis.
The drug should be administered with caution to patients with Reynaud's syndrome or pheochromocytoma.
When instilled in the eye, beta-blockers can be absorbed into the systemic circulation. In this case, the same side effects can be noted, as in systemic application. Cases of severe respiratory and cardiovascular disorders, including bronchospasm with fatal outcome in patients with bronchial asthma and death from heart failure are described.
Xonef® has minimal impact on blood pressure and heart rate. However, care should be taken when prescribing the drug to patients with AV-blockade of the I degree and mild and moderate heart failure. Treatment with Xonef® should be stopped immediately if the first symptoms of cardiovascular decompensation appear.
Xonef® contains a preservative benzalkonium chloride, which can be deposited on soft contact lenses and have a toxic effect on the eye tissue. Therefore, patients wearing contact lenses should be removed before using drops and installed back no earlier than 20 minutes after instillation.