Carteolol has not been detected in plasma following ocular instillation. However, as with other topically applied ophthalmic preparations, Carteolol may be absorbed systemically. The same adverse reactions found with systemic administration of beta-adrenergic blocking agents may occur with topical administration. For example, severe respiratory reactions and cardiac reactions, including death due to bronchospasm in patients with asthma, and rarely death in association with cardiac failure, have been reported with topical application of beta-adrenergic blocking agents (see CONTRAINDICATIONS).
Sympathetic stimulation may be essential for support of the circulation in individuals with diminished myocardial contractility, and its inhibition by beta-adrenergic receptor blockade may precipitate more severe failure.
In Patients Without a History of Cardiac Failure
Continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of cardiac failure, Carteolol Hydrochloride should be discontinued.
In patients with non-allergic bronchospasm or with a history of non-allergic bronchospasm (e.g., chronic bronchitis, emphysema), Carteolol Hydrochloride Ophthalmic Solution should be administered with caution since it may block bronchodilation produced by endogenous and exogenous catecholamine stimulation of beta2 receptors.
The necessity or desirability of withdrawal of beta-adrenergic blocking agents prior to major surgery is controversial. Beta-adrenergic receptor blockade impairs the ability of the heart to respond to beta-adrenergically mediated reflex stimuli. This may augment the risk of general anesthesia in surgical procedures. Some patients receiving beta-adrenergic receptor blocking agents have been subject to protracted severe hypotension during anesthesia. For these reasons, in patients undergoing elective surgery, gradual withdrawal of beta-adrenergic receptor blocking agents may be appropriate.
If necessary during surgery, the effects of beta-adrenergic blocking agents may be reversed by sufficient doses of such agonists as isoproterenol, dopamine, dobutamine or levarterenol (see OVERDOSAGE).
Beta-adrenergic blocking agents should be administered with caution in patients subject to spontaneous hypoglycemia or to diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents. Beta-adrenergic receptor blocking agents may mask the signs and symptoms of acute hypoglycemia.
Beta-adrenergic blocking agents may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism. Patients suspected of developing thyrotoxicosis should be managed carefully to avoid abrupt withdrawal of beta-adrenergic blocking agents which might precipitate a thyroid storm.
Carteolol Hydrochloride Ophthalmic Solution should be used with caution in patients with known hypersensitivity to other beta-adrenoceptor blocking agents.
Use with caution in patients with known diminished pulmonary function.
In patients with angle-closure glaucoma, the immediate objective of treatment is to reopen the angle. This requires constricting the pupil with a miotic. Carteolol has little or no effect on the pupil. When Carteolol is used to reduce elevated intraocular pressure in angle-closure glaucoma, it should be used with a miotic and not alone.
Information to the Patient
For topical use only. To prevent contaminating the dropper tip and solution, care should be taken not to touch the eyelids or surrounding areas with the dropper tip of the bottle. Keep bottle tightly closed when not in use. Protect from light.
Risk from Anaphylactic Reaction
While taking beta-blockers, patients with a history of atopy or a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated accidental, diagnostic or therapeutic challenge with such allergens. Such patients may be unresponsive to the usual doses of epinephrine used to treat anaphylactic reactions.
Beta-adrenergic blockade has been reported to potentiate muscle weakness consistent with certain myasthenic symptoms (e.g., diplopia, ptosis and generalized weakness).
Carteolol Hydrochloride Ophthalmic Solution should be used with caution in patients who are receiving a beta-adrenergic blocking agent orally, because of the potential for additive effects on systemic beta-blockade.
Close observation of the patient is recommended when a beta-blocker is administered to patients receiving catecholamine-depleting drugs such as reserpine, because of possible additive effects and the production of hypotension and/or marked bradycardia, which may produce vertigo, syncope, or postural hypotension.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carteolol hydrochloride did not produce carcinogenic effects at doses up to 40 mg/kg/day in two-year oral rat and mouse studies. Test of mutagenicity, including the Ames Test, recombinant (rec)-assay, in vivo cytogenetics and dominant lethal assay demonstrated no evidence for mutagenic potential. Fertility of male and female rats and male and female mice was unaffected by administration of carteolol hydrochloride dosages up to 150 mg/kg/day.
Pregnancy Category C
Carteolol hydrochloride increased resorptions and decreased fetal weights in rabbits and rats at maternally toxic doses approximately 1052 and 5264 times the maximum recommended human oral dose (10 mg/70 kg/day), respectively. A dose-related increase in wavy ribs was noted in the developing rat fetus when pregnant females received daily doses of approximately 212 times the maximum recommended human oral dose. No such effects were noted in pregnant mice subjected to up to 1052 times the maximum recommended human oral dose. There are no adequate and well-controlled studies in pregnant women. Carteolol Hydrochloride Ophthalmic Solution should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
It is not known whether this drug is excreted in human milk, although in animal studies carteolol has been shown to be excreted in breast milk. Caution should be exercised when Carteolol Hydrochloride Ophthalmic Solution is administered to nursing mothers.
Safety and effectiveness in pediatric patients have not been established.