Properties
What is it?
International Nonproprietary Name - Tetracainum Pharmacotherapeutic group – Local anesthetic. Description; A clear liquid with a colorless or yellowish tint. Composition: Active substance: Tetracaine hydrochloride – 0.05 g or 0.1 g; Excipients: Sodium chloride – 0.081 g or 0.072 g. Benzalkonium chloride – 0.0005 g, Water for injection – up to 10 ml. Indications Local anesthesia during short-term operations and manipulations in ophthalmological practice. Methods of administration and dosage Before surgical intervention, the preparation is instilled into the conjunctival sac in the amount of 1-2 drops (not more than 2-3 drops), if necessary, 1-2 additional drops are instilled during surgery. Side effects Photophobia, lacrimation, conjunctival chemosis, increased ophthalmotone. With prolonged use – keratitis, persistent corneal opacity, development of corneal synechiae with loss of visual acuity, delayed epithelialization. Systemic side effects may develop. Contraindications Hypersensitivity (including to other local anesthetics of the ester group or to para-aminobenzoic acid and its derivatives), damage or inflammation of mucous membranes, in well-vascularized areas, childhood (up to 10 years). Overdose Symptoms: Dizziness, asthenia, cyanosis, excitability, anxiety, tremor, convulsions, respiratory depression, collapse, nausea, vomiting, coma, atrioventricular block, methemoglobinemia. Treatment. Removal from skin and mucous membranes, gastric lavage (via probe) with activated charcoal, saline laxatives; with respiratory depression – artificial lung ventilation, oxygen therapy, with collapse – intravenous administration of plasma substitutes (saline solutions, Hemodez, Dextran preparations), vasoconstrictors (preferably myocardial stimulants), with convulsions – intravenous diazepam, with methemoglobinemia – intravenous administration of 1-2 mg/kg methylene blue or 100-200 mg ascorbic acid. Special instructions Do not use for prolonged or frequent use in ophthalmology (risk of corneal damage). Instruments and syringes that come into contact with tetracaine should not contain alkali residues (insoluble base is formed). Use during pregnancy and lactation Use with caution. Interaction with other drugs Reduces the antimicrobial activity of sulfonamides. Vasoconstrictors prolong the effect. Cholinesterase inhibitors (antimyasthenic, cyclophosphamide, insecticides, thiotepa) reduce tetracaine metabolism and increase its toxicity. Anticoagulants (dalteparin, enoxaparin, heparin, warfarin) increase the risk of bleeding. When tetracaine is administered with hypnotics and sedatives, their central nervous system depressant effect may be enhanced. When used with monoamine oxidase inhibitors, the risk of decreased blood pressure increases. Enhances and prolongs the effect of muscle relaxants. Beta-blockers slow down tetracaine metabolism.
