Dorzolamide

Pharmacological properties

dorzolamide is a potent inhibitor of carbonic anhydrase ii (ca-ii) in humans. after topical application, it reduces increased intraocular pressure, whether or not associated with glaucoma. increased intraocular pressure is the main risk factor in the pathogenesis of damage to the optic nerve and glaucomatous narrowing of the visual field.

A decrease in intraocular pressure with the use of dorzolamide is not accompanied by the development of such common adverse reactions characteristic of miotics as night blindness, accommodative spasm and constriction of the pupil. Does not affect or has a slight effect on blood pressure and heart rate.

Unlike oral preparations of carbonic anhydrase inhibitors, when applied topically, dorzolamide acts directly in the eye at significantly lower concentrations, and therefore this use is accompanied by less systemic effect.

The effectiveness of dorzolamide, which was used in patients with glaucoma or ocular hypertension 3 times a day (primary intraocular pressure ≥23 mm Hg) or 2 times a day as an additional therapy in the treatment of local β-adrenoreceptor blockers (primary intraocular pressure ≥22 mmHg) has been confirmed in clinical studies. When used both as monotherapy and in combination with β-adrenergic blockers, dorzolamide lowered intraocular pressure throughout the day, and this effect persisted for a long time. The effectiveness of dorzolamide after prolonged use as monotherapy was similar to the effectiveness of betaxolol and only slightly less than the effectiveness of timolol. When using dorzolamide as an additional therapy in the treatment of local β-adrenoreceptor blockers, an additional decrease in intraocular pressure was observed, similar to that with pilocarpine 2% 4 times a day.

Pharmacokinetics When applied topically, dorzolamide enters the systemic circulation.

Moderately binds to plasma proteins (about 33%). With prolonged use, dorzolamide accumulates in red blood cells as a result of selective binding to CA-II, while an extremely low concentration of free active substance is maintained in the blood plasma. Dorzolamide forms one N-deethylated metabolite, which inhibits CA-II to a lesser extent than the parent compound, but also inhibits the less active CA-I isoenzyme. The metabolite also accumulates in red blood cells, where it binds predominantly to CA-I.

It is excreted in the urine mainly unchanged; the metabolite is also excreted in the urine. After cessation of use, nonlinear leaching of dorzolamide from erythrocytes occurs, which first leads to a rapid decrease in the concentration of dorzolamide, followed by a slower elimination phase with T_½comprising about 4 months.

Indications

• Additional therapy in the treatment of local β-adrenergic blockers; monotherapy, when treatment with local β-adrenergic receptor blockers is not effective enough or is contraindicated; therapy of increased eye pressure with ocular hypertension, open-angle glaucoma, pseudoexfoliation glaucoma.

Application

The drug is intended for ophthalmic use only.

As monotherapy. The drug should be used 1 drop in the affected eye (s) 3 times a day.

As an adjunctive therapy. The drug is used 1 drop in the affected eye (s) 2 times a day.

If it is necessary to replace dorzolamide with another local anti-glaucoma agent, discontinue treatment with this agent and start using the drug the next day.

When using several local ophthalmic agents, they should be instilled with at least a 10-minute interval.

Before using the drug, you need to wash your hands and avoid any contact of the dropper tip with the eye or skin when instilling drops. If mistreated, eye drops can be contaminated with common bacteria that cause eye infections. The use of contaminated eye drops can lead to serious eye damage followed by loss of vision.

Children. Clinical data on the use of dorzolamide in children are limited. Do not use the drug in children.

Contraindications

Hypersensitivity to the active substance or other components of the drug; severe renal impairment (creatinine clearance 30 ml / min); hyperchloremic acidosis.

Side effects

The following adverse reactions have been reported with dorzolamide during clinical trials and post-marketing surveillance.

The frequency of adverse reactions is distributed as follows: very often (≥1 / 10); often (≥1 / 100, 1/10); infrequently (≥1 / 1000, 1/100); rarely (≥1 / 10,000, 1/1000); very rarely (1/10 000); frequency unknown (cannot be determined from available data).

From the nervous system: often - headache; rarely - paresthesia, dizziness.

From the side of the organ of vision: very often - burning and tingling; often - superficial punctate keratitis, lacrimation, conjunctivitis, blepharitis, itching in the eyes, eye irritation, blurred visual perception; infrequently - iridocyclitis; rarely - irritation, including redness, pain, clumping of the eyelids, transient nearsightedness (passing after discontinuation of treatment), corneal edema, hypotension of the eye, choroid detachment after filtration measures.

From the respiratory system, chest and mediastinal organs: rarely - nosebleeds.

From the alimentary canal: often - nausea, bitter taste in the mouth; rarely throat irritation, dry mouth.

On the part of the skin and subcutaneous tissue: rarely - contact dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis (Lyell syndrome).

From the kidneys and urinary tract: rarely - urolithiasis.

General disorders: often - asthenia / fatigue; rarely - hypersensitivity reactions, including palpebral reactions, angioedema, urticaria, itching, rash, shortness of breath, bronchospasm.

special instructions

Dorzolamide contains a sulfonamide group and, although applied topically, undergoes systemic absorption. In this regard, when it is used in the form of eye drops, adverse reactions characteristic of sulfonamides can occur, including Stevens-Johnson syndrome and toxic epidermal necrolysis (Lyell syndrome). in case of serious adverse reactions or if signs of hypersensitivity appear, the use of the drug should be discontinued.

If allergic reactions (such as conjunctivitis, reactions from the eyelids) develop, consideration should be given to discontinuing the drug.

Dorzolamide treatment in patients with impaired liver function has not been investigated. In such patients, the drug should be used with caution.

In patients with a previously diagnosed chronic corneal defect and / or history of intraocular surgery with dorzolamide, corneal edema and irreversible corneal decompensation were observed. In such patients, the drug should be used with caution.

The use of oral forms of carbonic anhydrase inhibitors is associated with the appearance of stones in the urinary tract due to water-electrolyte disturbances, in particular in patients with a history of kidney stones. Although in the case of dorzolamide, the appearance of water-electrolyte disturbances was not noted, rare cases of ureterolithiasis were recorded.Since dorzolamide is a localized carbonic anhydrase inhibitor that enters the general circulation, patients with a history of kidney stones are at a higher risk of developing ureterolithiasis in connection with the use of dorzolamide.

During the intake of drugs that inhibit the production of aqueous humor after filtration measures, cases of exfoliation of the choroid were observed.

In the treatment of patients with acute angle-closure glaucoma, it is necessary, in addition to the use of drugs that reduce intraocular pressure, also other therapeutic measures. The use of dorzolamide in patients with acute angle-closure glaucoma has not been investigated.

The drug contains a preservative benzalkonium chloride, which can cause eye irritation and discoloration of soft contact lenses. Contact lenses should be removed before using the drug and reinserted no earlier than 15 minutes after instillation.

Use during pregnancy or lactation. Adequate and well-controlled studies of the use of dorzolamide in pregnant women are absent. The drug is not recommended for use during pregnancy.

It is not known whether dorzolamide passes into breast milk. If it is necessary to use the drug, breast-feeding should be discontinued.

The ability to influence the reaction rate when driving vehicles or other mechanisms. Studies of the effect of dorzolamide on the ability to drive vehicles or other mechanisms have not been conducted. When using the drug, it is possible to develop adverse reactions, such as dizziness and visual impairment, which can affect the ability to drive vehicles or other mechanisms.

Interactions

Special studies of the interaction of dorzolamide with other agents have not been conducted.

In clinical studies, dorzolamide was used simultaneously with timolol and betaxolol in the form of eye drops, with systemic drugs: ACE inhibitors, calcium channel blockers, diuretics and NSAIDs, including acetylsalicylic acid, as well as with hormonal agents (e.g. estrogen, insulin, thyroxine) that was not accompanied by the development of drug interactions.

It is possible to enhance the overall effect of carbonic anhydrase inhibitors in patients who simultaneously take an oral carbonic anhydrase inhibitor and dorzolamide. The simultaneous use of dorzolamide and oral administration of carbonic anhydrase inhibitors have not been studied and is not recommended.

The interaction of dorzolamide with myotics and adrenomimetics in the treatment of glaucoma is not well understood.

Overdose

Symptoms data on an overdose of dorzolamide in humans are limited. the appearance of such symptoms was observed: after taking orally - drowsiness; after topical application - nausea, dizziness, headache, feeling of tiredness, atypical dreams and dysphagia. electrolyte disturbances, asthenia and symptoms from the central nervous system may occur.

Treatment. In case of an overdose, carry out symptomatic and supportive therapy. It is necessary to check the concentration of electrolytes (in particular potassium) in blood plasma and determine the pH of the blood.

Storage conditions

At a temperature not exceeding 25 ° c.