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Data Sheet

MINIMS TETRACAINE HYDROCHLORIDE

tetracaine hydrochloride eye drops

Qualitative and Quantitative Composition

Single-use, clear, colourless, sterile eye drops containing tetracaine hydrochloride Ph.Eur. 0.5% w/v or 1.0% w/v solutions.

Pharmaceutical Form

Single-use, sterile eye drops.

Clinical Particulars

Therapeutic Indications

Ocular anaesthetic for topical instillation into the conjunctival sac.

Posology and Method of Administration

Adults and children

One drop or as required. Each Minims unit should be discarded after use.

Contraindications

Not to be used in patients with a known hypersensitivity to the product.

Tetracaine is hydrolysed in the body to p-amino-benzoic acid and should not therefore be used in patients being treated with sulphonamides.

In view of the immaturity of the enzyme system which metabolises the ester type local anaesthetics in premature babies, tetracaine should be avoided in these patients.

Special Warnings and Special Precautions for Use

The anaesthetised eye should be protected from dust and bacterial contamination.

The cornea may be damaged by prolonged application of anaesthetic eye drops.

Systemic absorption may be reduced by compressing the lacrimal sac at the medial canthus for a minute during and following the instillation of the drops. (This blocks the passage of the drops via the naso lacrimal duct to the wide absorptive area of the nasal and pharyngeal mucosa. It is especially advisable in children.)

Interaction With Other Medicaments and Other Forms of Interaction

Tetracaine should not be used in patients being treated with sulphonamides (see contraindications above).

Pregnancy and Lactation

Safety for use in pregnancy and lactation has not been established, therefore, use only when considered essential by the physician.

Effects on Ability to Drive and Use Machines

May cause transient blurring of vision on instillation. Warn patients not to drive or operate hazardous machinery unless vision is clear.

Undesirable Effects

Tetracaine may give rise to dermatitis in hypersensitive patients.

On instillation an initial burning sensation may be experienced. This may last for up to 30 seconds.

Corneal disorders such a superficial punctuate keratitis or edema may be observed following short-term application of Tetracaine (amethocaine) eye drops for topical anaesthesia.

The cornea may be damaged by prolonged application eye drops.

Overdose

Not expected.

Pharmacological Properties

Pharmacodynamic Properties

Tetracaine hydrochloride is used as a local anaesthetic which acts by reversibly blocking the propagation and conduction of nerve impulses along nerve axons. Tetracaine stabilises the nerve membrane, preventing the increase in sodium permeability necessary for the production of an action potential.

Pharmacokinetic Properties

Tetracaine is a weak base (pKa 8.5), therefore, significant changes in the rate of ionised lipid soluble drug uptake may occur with changes in the acid base balance.

In vitro studies have shown that tetracaine has a high affinity for melanin, therefore, differences in duration of action may be expected between deeply pigmented eyes and less pigmented eyes.

The primary site of metabolism for tetracaine is the plasma. Pseudocholinesterases in the plasma hydrolyse tetracaine to 4-aminobenzoic acid. Unmetabolised drug is excreted in the urine.

Preclinical Safety Data

No adverse safety issues were detected during the development of this formulation. The active ingredient is well established in clinical ophthalmology.

Pharmaceutical Particulars

List of Excipients

Hydrochloric Acid

Purified Water

Incompatibilities

None known.

Shelf Life

Unopened: 30 months.

Special Precautions for Storage

Store at 2°-8°C. Do not freeze. Protect from light.

Medicine Classification

Prescription medicine.

Nature and Contents of Container

A sealed conical shaped polypropylene container fitted with a twist and pull off cap. Overwrapped in an individual polypropylene/paper pouch. Each container holds approximately 0.5ml of solution.

Instructions for Use/Handling

Each Minims unit should be discarded after use.

NAME AND ADDRESS

Bausch & Lomb (NZ) Ltd
c/o New Zealand Medical & Scientific Limited
2A Fisher Crescent
Mount Wellington
Auckland
NEW ZEALAND

Date OF PREPARATION

22 July 2008