Properties
What is it?
Trade name: Midoptik International Nonproprietary Name: Phenylephrine Description: Clear liquid, colorless or with a yellowish tint. Composition: Active substance: Phenylephrine hydrochloride – 0.25 g; Excipients: Boric acid – 0.05 g, Sodium metabisulfite – 0.004 g, Disodium edetate – 0.0005 g, Preservative – Benzalkonium chloride – 0.001 g, Water for injection – up to 10 ml. Dosage form: 2.5% eye drops Pharmacotherapeutic group: Alpha-adrenomimetic, vasoconstrictor agent. Pharmacological properties Pharmacodynamics: A synthetic sympathomimetic amine of direct action that stimulates alpha-adrenoreceptors. It acts on the alpha-adrenoreceptors of the pupillary dilator, causing pupillary dilation without affecting accommodation; it acts on the alpha-adrenoreceptors of conjunctival arterioles, causing arteriolar constriction. Since phenylephrine has a negligible effect on the ciliary muscle, mydriasis occurs without cycloplegia. In combination with miotics, it can reduce intraocular pressure in open-angle glaucoma. The time to achieve maximum mydriasis is 15-60 minutes. Duration of action is 1-3 hours. Pharmacokinetics: After local application, systemic absorption of phenylephrine may occur with the manifestation of sympathomimetic effects. The preparation is intended for local use, and its activity does not correlate with the concentration of active substances in blood plasma. Indications: Pupillary dilation in intraocular surgery; in diagnostic studies: for ophthalmoscopy, retinoscopy, refraction; treatment of uveitis complicated by synechiae; prevention of synechiae. Routes of administration and dosage: To achieve mydriasis and vasoconstriction – one drop, repeated after 1 hour if necessary. For the treatment of uveitis complicated by synechiae and for the prevention of synechiae – one drop, but no more than 3 times a day. If necessary, treatment is repeated the next day. Before surgical intervention – one drop 30-60 minutes before surgery; during ophthalmoscopy – one drop 15-30 minutes before examination. Side effects: Local reactions: allergic reactions (burning, discomfort in the eyes, conjunctival hyperemia), pain in the superciliary region, lacrimation, photosensitivity. Systemic reactions: dizziness, headache, tachycardia, increased blood pressure, increased sweating, pallor, anxiety. Contraindications: Hypersensitivity to phenylephrine and sulfites, ventricular fibrillation, tendency to angiospasm, severe cerebrovascular disorders, decompensated heart failure, severe forms of GID, pheochromocytoma, hyperthyroidism, pronounced atherosclerosis, angle-closure glaucoma, neonatal period (for low birth weight infants). With caution: Angina pectoris of functional class III-IV, diabetes mellitus, arterial hypertension, idiopathic orthostatic arterial hypotension, pregnancy, lactation, elderly age, children under 12 years of age. Overdose: Systemic side effects are usually not observed with local use, but with overdose, especially with prolonged use, cardiac rhythm disturbances, increased blood pressure, insomnia, agitation, and pallor may occur. Specific treatment: For hypertensive effect, an alpha-adrenoblocker such as phentolamine 5-10 mg IV may be prescribed, repeated if necessary. Special instructions: During the period of drug administration, it is necessary to refrain from driving and potentially hazardous activities that require concentration and speed of psychomotor reactions. If wearing contact lenses, the drug should not be instilled until the lenses are removed. To reduce systemic absorption, apply pressure to the conjunctival sac for 2-3 minutes after instillation of the drug. Caution should be exercised when using the drug in elderly patients, as systemic side effects are mainly observed in this age group. Repeated use of eye drops in children and elderly patients can cause a paradoxical effect – miosis and reduced mydriatic effect. Caution is required when prescribing phenylephrine to patients who are currently taking MAO inhibitors or have taken them within the previous 3 weeks, as they enhance the adrenergic effects of sympathomimetics and increase the risk of cardiovascular side effects. Pregnancy and lactation: Prescribed with caution during pregnancy and lactation. Not recommended for administration to infants with hypotrophy. Interactions: Potentiation of the pressor effect is observed if tricyclic antidepressants, maprotiline, MAO inhibitors, including furazolidone, procarbazine, and selegiline, are administered concurrently with the drug. Potentiation of mydriatic and pressor effects, increased risk of elevated blood pressure and arrhythmias is caused by guanadrel or guanethidine. Pharmaceutically incompatible with the local anesthetic butacaine. Storage conditions and shelf life: Store at a temperature of 8-25°C, out of reach of children. Shelf life – 2 years. Do not use the drug after the expiration date indicated on the packaging. After opening the vial, the drug should be used within 1 month. Packaging form: In polyethylene dropper bottles – 10 ml. 10 dropper bottles in a cardboard block. Dispensing conditions: By prescription
