Cycloplegic – Mydriatic – Anticholinergic
Cyclopentolate is an anticholinergic agent that induces relaxation of the sphincter of the iris and the ciliary muscles. When applied topically to the eyes, it causes a rapid, intense cycloplegic and mydriatic effect that is maximal in 15 to 60 minutes; recovery usually occurs within 24 hours. The cycloplegic and mydriatic effects are slower in onset and longer in duration in patients who have dark pigmented irises.
Indications: Cyclopentolate is used mainly to produce mydriasis and cycloplegia for diagnostic purposes.
Contraindications: Cyclopentolate is contraindicated in patients with angle-closure glaucoma or in patients with shallow anterior chambers (see Warnings).
Cyclopentolate should not be used in patients, especially children, who have previously experienced a severe systemic reaction to the drug, or in patients with hypersensitivity to any component of a cyclopentolate formulation.
Warnings: Cyclopentolate may cause increased intraocular pressure. Angle-closure glaucoma may be induced by cyclopentolate in patients with higher susceptibility to increased intraocular pressure including the elderly and individuals with shallow anterior chambers.
Very rarely, some patients with open-angle glaucoma may experience abrupt elevations in intraocular pressure.
The use of cyclopentolate in patients with higher susceptibility to increased intraocular pressure should be preceded by complete ocular examination, including measurement of intraocular pressure.
Precautions: Cyclopentolate may cause an increase in intraocular pressure which if sustained, can potentially lead to irreversible loss of vision (see Warnings). The drug should be discontinued and the physician consulted immediately if eye pain, blurring of vision, rapid pulse or dizziness occurs.
Patients may require the use of dark glasses following the application of cyclopentolate, due to photophobia associated with mydriasis.
Patients should be advised to contact their physician if blurred vision and photophobia continue for more than 48 hours after discontinuing cyclopentolate.
Systemic absorption of topical cyclopentolate from the nasal mucosal surfaces may result in systemic adverse effects. This is particularly the case in children, who are most susceptible to the drug’s adverse effects. If signs of systemic toxicity appear, such as dry mouth, tachycardia or dizziness, the dosage schedule should be reduced or the drug discontinued.
Children: Infants and young children and children with blond hair or blue eyes may be especially sensitive to the effects of cyclopentolate, increasing the chance of side effects during treatment. Use of cyclopentolate in children has been associated with psychotic reactions and behavioral disturbances.
Drug Interactions : Cyclopentolate may affect the action of concomitantly administered drugs such as: antihistamines, isoniazid, MAO inhibitors, phenothiazines, procainamide, disopyramide, propranolol, quinidine and tricyclic antidepressants. Anticholinergic agents, such as cyclopentolate, antagonize miosis and ciliary body contraction induced by cholinesterase inhibitors and cholinergic agonists.
Adverse Effects: Blinding acute angle-closure glaucoma and raised intraocular pressure may occur during cyclopentolate therapy. The mydriasis may be reduced by the intraocular application of pilocarpine, physostigmine or isoflurophate.
Transient burning sensation of the eye is more likely with the 1% than the 0.5% solution.
Systemic effects, resulting from excessive absorption from mucosal surfaces or from ingestion of the drug, may include xerostomia, flushing, tachycardia and urinary retention. More severe systemic effects are tachypnea, scarlatiniform rash, delirium, psychosis, fever, stupor, coma, respiratory failure and death.
tag_OverdoseOverdose: Symptoms: Tachycardia, dizziness, dry mouth, behavioral disturbances, uncoordination or drowsiness.
Treatment: Symptomatic and supportive therapy. In most cases of topical exposure, patients recover without specific therapy. If drops are accidentally ingested, more pronounced anticholinergic effects may occur. Emesis is not advised due to the CNS depression and delirium that may be present. Gastric lavage may be indicated in cases of recent ingestion. Administer activated charcoal and cathartic if no contraindications. Physostigmine should be reserved for severe cases unresponsive to other measures.
Dosage: To produce mydriasis and cycloplegia for diagnostic purposes, in adults and children over 1 year: 1 drop instilled in the eye(s), followed by a second drop 5 minutes later, if necessary. Drops should be administered 40 to 50 minutes prior to the procedure. To minimize systemic absorption, finger pressure should be applied to the lacrimal sac for 2 to 3 minutes following administration. Alternatively, the eyelids should be kept closed for 2 to 5 minutes following instillation.
Patients with heavily pigmented irides may require larger doses.
Complete recovery from mydriasis and cycloplegia should occur within 24 hours.
CYCLOPENTOLATE HClGeneral Monograph,Cycloplegic – Mydriatic – Anticholinergic