OVERDOSAGE
No specific information on emergency treatment of overdosage with Kerlone is available. The most common effects expected are bradycardia, congestive heart failure, hypotension, bronchospasm, and hypoglycemia. In one acute overdosage of betaxolol, a 16-year-old female recovered fully after ingesting 460 mg.
Oral LD50s are 350 to 400 mg betaxolol/kg in mice and 860 to 980 mg/kg in rats.
In the case of overdosage, treatment with Kerlone should be stopped and the patient carefully observed. Hemodialysis or peritoneal dialysis does not remove substantial amounts of the drug. In addition to gastric lavage, the following therapeutic measures are suggested if warranted:
Hypotension
Use sympathomimetic pressor drug therapy, such as dopamine, dobutamine, or norepinephrine. In refractory cases of overdosage of other beta-blockers, the use of glucagon hydrochloride has been reported to be useful.
Bradycardia
Atropine should be administered. If there is no response to vagal blockade, isoproterenol should be administered cautiously. (see Warnings: Anesthesia and major surgery ). In refractory cases the use of a transvenous cardiac pacemaker may be considered.
Acute cardiac failure
Conventional therapy including digitalis, diuretics, and oxygen should be instituted immediately.
Bronchospasm
Use a β2-agonist. Additional therapy with aminophylline may be considered.
Heart block (2nd- or 3rd-degree)
Use isoproterenol or a transvenous cardiac pacemaker.
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