Phenicamide, eye drops 8 mg/ml+50 mg/ml 10 ml

Pharmacotherapeutic group

Ophthalmic diagnostic agent (m-cholinoblocker + alpha-adrenomimetic).

ATX code: S01FA56

Pharmacological properties

Pharmacodynamics

Tropicamide.M-cholinoblocker, blocks the m-cholinoreceptors of the pupillary sphincter and ciliary muscle, causing transient mydriasis and paralysis of accommodation. Slightly increases intraocular pressure. Mydriasis against the background of tropicamide application develops in 5-10 minutes and reaches its maximum by 20-45 minutes. Maximum pupil dilation is maintained for 1 hour and normalizes after 6 hours.

Phenylephrine.A nonselective alpha-adrenomimetic. When instilled into the eye, it causes dilation of the pupil, improves the outflow of intraocular fluid and narrows the conjunctival vessels. Phenylephrine has a pronounced stimulatory effect on postsynaptic alpha-adrenoreceptors, has a very weak effect on beta1-adrenoreceptors. It has a vasoconstrictor effect similar to that of norepinephrine (noradrenaline), while it has almost no chronotropic and inotropic effect on the heart. The vasopressor effect of phenylephrine is weaker than that of norepinephrine, but it is longer lasting. After instillation, phenylephrine contracts the dilator of the pupil and the smooth muscles of the conjunctival arterioles, thereby causing pupil dilation. Midriasis occurs within 10-60 min after a single injection and persists for 4-6 h. Phenylephrine-induced mydriasis is not accompanied by cycloplegia.

Phenylephrine complements the effects of tropicamide because their mechanisms of action are different. Phenylephrine combined with tropicamide reduces or stops tropicamide’s ability to increase intraocular pressure.

Pharmacokinetics

Tropicamide. Easily penetrates the tissues of the eye and is rapidly absorbed into the bloodstream. Using a modified radioreceptor assay, the lower limit of determination of tropicamide in plasma was less than 240 ng/mL, and the range of determination was 240 ng/mL to 10 ng/mL. The mean maximum plasma concentration at the fifth minute after injection was 2.8±1.7 ng/ml. At minute 60, the plasma concentration of tropicamide was 0.46±0.51 ng/ml and below 240 ng/ml at minute 120.

Phenylephrine.Phenylephrine readily penetrates ocular tissues, maximum plasma concentration occurs 10-20 min after topical administration. Phenylephrine is excreted by the kidneys unchanged (< 20%) or as inactive metabolites.

Indications

It is used as a mydriatic agent:

• in diagnostic ophthalmic procedures;
• before surgical and laser operations.

Active ingredient

Tropicamide, Phenylephrine

Composition

The composition of the drug per 1 ml:
Active ingredients:
Tropicamide 8.0 mg
Phenylephrine hydrochloride 50.0 mg

Excipients:
Benzalkonium chloride 0.1 mg
Sodium hydrophosphate dihydrate 0.28 mg
Sodium dihydrophosphate dihydrate 0.005 mg
Sodium chloride 4.5 mg
Dinatrium edetate dihydrate (trilon B) 0.5 mg
1 M hydrochloric acid solution or 1 M sodium hydroxide solution to pH 3.0 – 5.8
Water for injection up to 1 ml

How to take, the dosage

To dilate the pupil during diagnostic ophthalmologic and surgical interventions, 1-2 drops are injected into the conjunctival cavity 15-30 minutes before the procedure or surgery.

Interaction

Adrenomimetics increase and m-cholinomimetics decrease the effect of tropicamide. Tricyclic antidepressants, phenothiazines, amantadine, quinidine, antihistamines increase the likelihood of systemic side effects of tropicamide.

Atropine enhances the mydriatic effect of phenylephrine. Concomitant use with MAO inhibitors, and for 21 days after discontinuation of their administration, increases the risk of systemic adrenergic effects.

The vasopressor effect of alpha-adrenomimetics may also be enhanced when co-administered with tricyclic antidepressants, propranolol, guanethidine, methyldopa and m-cholinoblockers. Beta-adrenoblockers increase the risk of a sharp increase in blood pressure. Phenylephrine increases the risk of cardiovascular depression during inhaled general anesthesia.

Phenylephrine may increase the vasoconstrictor effect of beta-adrenoblockers by inhibiting vasodilation.

Phenylephrine and guanethidine or any other adrenoblocker or monoamine reuptake inhibitor are not recommended together due to the risk of hypertensive crisis.

Concomitant use with monoamine oxidase inhibitors and for three weeks after stopping their administration increases the risk of systemic adrenergic effects.

The vasomotor effects of adrenomimetics may also be enhanced when combined with tricyclic antidepressants, methyldopa and m-cholinoblockers.

Pre instillation of local anesthetics may increase systemic absorption of active agents and prolong mydriasis.

Special Instructions

Due to significant contraction of the dilator of the pupil 30-45 minutes after instillation, pigment particles from the pigment layer of the iris may be detected in the anterior chamber humor. Suspension in the chamber humor must be differentiated with manifestations of anterior uveitis or with the ingress of blood cells into the moisture of the anterior chamber.

Benzalkonium chloride, which is commonly used as a preservative in ophthalmic products, can cause pitting keratopathy and/or toxic ulcerative keratopathy. Because it contains benzalkonium chloride, close monitoring is required for frequent or prolonged use in patients with dry eye syndrome or in cases of corneal damage. Benzalkonium chloride may discolor soft contact lenses. Soft contact lenses should be removed before application and put on again 15 minutes after dosing.

Cycloplegics may increase intraocular pressure and provoke closed-angle glaucoma in predisposed individuals, which should be considered and carefully evaluated before starting treatment; tropicamide may induce psychosis.

When using the drops, contact of the tip of the bottle with any surface should be avoided. To reduce the risk of systemic side effects, light finger pressure is recommended in the area of the projection of the lacrimal sacs at the inner corner of the eye for 1-2 minutes after dosing.

Influence on driving and operating ability

After use of the drug due to changes in accommodation and pupil width visual acuity may decrease, therefore, the use of the drug is not recommended for driving vehicles and other potentially dangerous activities requiring high concentration and quick psychomotor reactions.

Synopsis

Transparent colorless to yellow or brownish-yellow liquid.

Contraindications

Hypersensitivity to any of the components, childhood under 18 years of age, narrow-angle and closed-angle glaucoma, mixed glaucoma, cardiovascular disease (including coronary artery disease, angina pectoris, arrhythmia, hypertensive crisis), renal porphyria, thyrotoxicosis, type I diabetes, pregnancy, breast-feeding, concurrent use (and within 3 weeks after their withdrawal) of monoamine oxidase inhibitors (MAOIs).

With caution

. Type II diabetes mellitus, advanced age (risk of ventricular arrhythmias and myocardial infarction in patients with cardiovascular disease), patients with cerebrovascular disease, conditions after surgical intervention (reduced conjunctival healing).

Side effects

Local reactions

. Allergic reactions, increased intraocular pressure, transient pain, burning in the eye and photophobia, transient visual impairment, release of pigment into aqueous humor with a temporary increase in intraocular pressure, blockage of the anterior chamber angle (with angle narrowing), pain in the brow area, lacrimation, conjunctival hyperemia, keratitis; Rarely, reactive miosis the day after administration (repeated instillations of the drug at this time may give less significant mydriasis than the day before; this effect is more common in elderly patients).

Systemic reactions

Pale skin, dry mouth, red and dry skin, contact dermatitis, headache, fainting, decreased blood pressure, palpitations, tachycardia and arrhythmia, bradycardia, ventricular occlusion of coronary arteries, pulmonary embolism, CNS disturbances and muscle rigidity, frequent urge to urinate, difficulty in urination, decreased gastrointestinal tone and peristalsis, leading to constipation. Sometimes there is vomiting and dizziness. In elderly patients with cardiovascular diseases ventricular arrhythmias and myocardial infarction are possible.

Overdose

Tropicamide and phenylephrine overdose have not been reported with topical administration.

Symptoms(in case of accidental ingestion):Dry skin and mucous membranes, hyperthermia, tachycardia, mydriasis, agitation, seizures, coma, respiratory depression.

Treatment:Gastric lavage, administration of activated charcoal; as an antidote – physostigmine (0.03 mg/kg intravenously slowly), benzodiazepines; to eliminate hyperthermia – cold compresses. To stop the systemic action of phenylephrine – alpha-adrenoblockers (5-10 mg of phentolamine intravenously, repeat the injection if necessary).

Pregnancy use

The drug is contraindicated in pregnancy and during breast-feeding.

Similarities

Midrimax