Mydrilate
Mydrilate Uses, Dosage, Side Effects, Food Interaction and all others data.
Mydrilate is an anticholinergic drug that blocks the responses of the sphincter muscle of the iris and the accommodative muscle of the ciliary body to stimulation by acetylcholine. Dilation of the pupil (mydriasis) and paralysis of accommodation (cycloplegia) result.
Mydrilate is an anti-muscarinic in the same class as atropine and scopolamine. Mydrilate blocks the receptors in the muscles of the eye (muscarinic receptors). These receptors are involved controlling the pupil size and the shape of the lens. Mydrilate thus 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.
| Trade Name | Mydrilate |
| Availability | Prescription only |
| Generic | Cyclopentolate |
| Cyclopentolate Other Names | Ciclopentolato, Cyclopentolate, Cyclopentolatum |
| Related Drugs | epinephrine, atropine ophthalmic, phenylephrine ophthalmic, EpiPen, Adrenalin, Cyclogyl, homatropine ophthalmic, Isopto Atropine, Mydriacyl |
| Type | |
| Formula | C17H25NO3 |
| Weight | Average: 291.3853 Monoisotopic: 291.183443671 |
| Groups | Approved |
| Therapeutic Class | Mydriatic and Cycloplegic agents |
| Manufacturer | Intrapharm Laboratories Limited |
| Available Country | United Kingdom, |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Mydrilate is used mainly to produce mydriasis and cycloplegia for diagnostic purposes.
Mydrilate is also used to associated treatment for these conditions: Anterior Uveitis (AU)
How Mydrilate works
By blocking muscarinic receptors, cyclopentolate produces dilatation of the pupil (mydriasis) and prevents the eye from accommodating for near vision (cycloplegia).
Dosage
Mydrilate dosage
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 irises may require larger doses. Complete recovery from mydriasis and cycloplegia should occur within 24 hours.
Side 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 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.
Toxicity
Oral LD50 in the rat is 4000 mg/kg and 960 mg/kg in the mouse. Symptoms of overdose include tachycardia, dizziness, dry mouth, behavioral disturbances, uncoordination and drowsiness.
Precaution
Mydrilate may cause an increase in intraocular pressure which if sustained, can potentially lead to irreversible loss of vision. 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
Interaction
Mydrilate 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.
Food Interaction
No interactions found.Elimination Route
Absorbed following ophthalmic administration.
Pregnancy & Breastfeeding use
pregnancy category C. Animal studies have not been reported. There are no controlled data in human pregnancy. Mydrilate ophthalmic is only recommended for use during pregnancy when benefit outweighs risk.
Contraindication
Mydrilate is contraindicated in patients with angle-closure glaucoma or in patients with shallow anterior chambers. Mydrilate 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.
Special Warning
Infants, 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.
Storage Condition
Store in a cool and dry place, away from light. Keep out of reach of children.
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