Midrimax, eye drops 5 ml

Preparing for diagnostic procedures

Indications

Used as a mydriatic agent:

1) for diagnostic ophthalmological procedures;

2) before surgical and laser operations.

Pharmacological effect

Pharmacotherapeutic group

ophthalmological diseases diagnostic tool (m-anticholinergic agent + alpha-adrenergic agonist)

Pharmacodynamics:

Phenylephrine is a non-selective α-adrenergic agonist. When instilled into the eye, it causes dilation of the pupil, improves the outflow of intraocular fluid and constricts the vessels of the conjunctiva. Phenylephrine has a pronounced stimulating effect on postsynaptic α-adrenergic receptors, but has a very weak effect on β1-adrenergic receptors.

It has a vasoconstrictor effect similar to the action of norepinephrine (norepinephrine), while it has virtually no chronotropic and inotropic effects on the heart. The vasopressor effect of phenylephrine is weaker than that of norepinephrine, but is longer lasting. After instillation, phenylephrine contracts the pupillary dilator and smooth muscle of the conjunctival arterioles, thereby causing pupillary dilation. Mydriasis occurs within 10-60 minutes after a single instillation and persists for 4-6 hours.

Mydriasis caused by phenylephrine is not accompanied by cycloplegia. Phenylephrine complements the action of tropicamide, since their mechanisms of action are different. Administration of phenylephrine together with tropicamide reduces or stops the ability of tropicamide to increase intraocular pressure.

Tropicamide is an m-cholinergic blocker that blocks m-cholinergic receptors of the sphincter of the pupil and ciliary muscle, causing short-term mydriasis and paralysis of accommodation. Slightly increases intraocular pressure. Mydriasis during the use of tropicamide develops after 5-10 minutes and reaches a maximum at 20-45 minutes.

Maximum pupil dilation persists for 1 hour and returns to normal after 6 hours.
Pharmacokinetics:

Phenylephrine easily penetrates the eye tissue, the maximum plasma concentration occurs 10-20 minutes after topical application. Phenylephrine is excreted by the kidneys unchanged (<20%) or in the form of inactive metabolites.

Tropicamide easily penetrates the eye tissue and is quickly absorbed into the bloodstream. When using a modified radioreceptor assay, the lower limit of determination of tropicamide in plasma was less than 240 ng/ml, the detection range was 240 ng/ml-10 ng/ml. The average maximum plasma concentration at the fifth minute after administration was 2.8 ± 1.7 ng/ml. At the 60th minute, the concentration of tropicamide in plasma was 0.46 ± 0.51 ng/ml, and at the 120th minute it was below 240 ng/ml.

Special instructions

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

The preservatives contained in the drug can be absorbed by soft contact lenses. The drug may irritate the eye when wearing contact lenses, so any contact lenses should be removed before instillation and put on no earlier than 15 minutes after it.

To reduce the risk of developing systemic side effects, it is recommended to apply light pressure with a finger on the area of ​​projection of the lacrimal sacs at the inner corner of the eye for 1-2 minutes after instillation.

Impact on the ability to drive vehicles and machinery:

After using the drug, due to changes in accommodation and pupil width, visual acuity may decrease, so the use of the drug is not recommended when driving vehicles, vehicles and when engaging in other potentially hazardous activities that require increased concentration and speed of psychomotor reactions.

Active ingredient

Tropicamide, Phenylephrine

Composition

Each 1 ml of the drug contains:

active substance: phenylephrine hydrochloride 50.0 mg, tropicamide 8.0 mg;

excipients: sodium metabisulfite 2 mg, benzalkonium chloride 0.1 mg, disodium edetate 1.0 mg, hypromellose 5.0 mg, sodium hydroxide q.s., hydrochloric acid q.s., water for injection up to 1 ml.

Contraindications

– Hypersensitivity to any of the components;

– narrow-angle and closed-angle glaucoma;

– age up to 18 years;

– diseases of the cardiovascular system (including coronary sclerosis, angina pectoris, arrhythmia, hypertensive crisis);

– thyrotoxicosis;

– diabetes mellitus type 1;

– simultaneous use (as well as 3 weeks after their withdrawal) of monoamine oxidase inhibitors (MAO);

– pregnancy;

– period of breastfeeding.

With caution:
Type 2 diabetes mellitus, old age (risk of developing ventricular arrhythmias and myocardial infarction in patients with diseases of the cardiovascular system).
Directions for use and dosage:
To dilate the pupil during diagnostic ophthalmological and surgical interventions, 1-2 drops are instilled into the conjunctival sac 15-30 minutes before the procedure or surgery.

Side Effects

Local:

Allergic reactions, increased intraocular pressure, transient pain, burning in the eye and photophobia, transient decreased vision, allergic reactions, release of pigment into the aqueous humor with a temporary increase in intraocular pressure, blocking the anterior chamber angle (with a narrowing of the angle), pain in the brow ridges, lacrimation, conjunctival hyperemia, keratitis; rarely – reactive miosis the next day after use (repeated instillations of the drug at this time may produce less pronounced mydriasis than the day before; this effect is more common in elderly patients).

System:

Pale skin, dry mouth, redness and dryness of the skin, contact dermatitis, headache, bradycardia, tachycardia and arrhythmia, increased blood pressure, ventricular occlusion of the coronary arteries, pulmonary embolism, central nervous system disorders and muscle rigidity, frequent urination, difficulty urinating, decreased tone gastrointestinal tract and peristalsis, leading to constipation. Sometimes – vomiting and dizziness.
In elderly patients with diseases of the cardiovascular system, ventricular arrhythmias and myocardial infarction are possible.

Interaction

– When prescribing β-blockers, it is possible to enhance the vasoconstrictor effect of phenylephrine due to their suppression of vasodilation.

– Due to the risk of hypertensive crisis, the combined use of phenylephrine and guanethidine, as well as any other adrenergic blocker or monoamine reuptake inhibitor, is not recommended.

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

– The vasopressor effect of adrenergic agonists can also be enhanced when used together with tricyclic antidepressants, methyldopa and m-anticholinergics.

– Pre-instillation of local anesthetics can increase systemic absorption of active substances and prolong mydriasis

Overdose

Symptoms (in case of accidental ingestion of the drug): dry skin and mucous membranes, hyperthermia, tachycardia, mydriasis, agitation, convulsions, coma, respiratory depression.

Treatment: gastric lavage, taking activated carbon; as an antidote – physostigmine (0.03 mg/kg intravenously slowly), benzodiazepines; to eliminate hyperthermia – cold compresses. To stop the systemic effect of phenylephrine, use α-adrenergic blockers (5-10 mg of phentolamine intravenously, repeat the injection if necessary).

Storage conditions

Store at a temperature not exceeding 25 °C, in a place protected from light.
Do not freeze. Keep out of the reach of children.

Shelf life

2 years.

1 month after opening the bottle.

Do not use after the expiration date stated on the package.

Manufacturer

Sentiss Pharma Pvt.Ltd, India