Indications
Tetracaine (also called amethocaine) is a local anaesthetic used to numb the skin or a surface before a painful procedure. As a cream or gel it numbs the skin before needle insertion, drip placement or blood tests. As a spray or solution it is used by health professionals to numb the mouth, throat or nose before examinations, and as eye drops to numb the eye surface.
How It Works
Tetracaine blocks sodium channels in nerve endings, which stops pain signals from travelling to the brain. The area becomes numb for a period of time and feeling returns as the medicine wears off.
Dosage and Administration
Use only as directed by a doctor, nurse or the product label. Skin cream is usually applied in a thick layer on intact skin and covered for a set time (often 30 to 45 minutes) before the procedure, then wiped off. Sprays, throat and eye preparations are applied by a health professional. Do not use on large areas, broken skin or for longer than advised.
Interactions
- Other local anaesthetics such as Lidocaine increase the total dose and risk of side effects.
- Tetracaine may reduce the effect of sulphonamide antibiotics.
- Use with care with antiarrhythmic medicines such as Amiodarone.
Contraindications
- Allergy to tetracaine or other ester-type local anaesthetics (such as Benzocaine or Procaine), or to PABA.
- Broken, inflamed or damaged skin, mucous membranes of the genitals (for the skin cream), and premature babies or newborns under 1 month, unless a doctor advises otherwise.
Side Effects
Common effects at the application site include mild redness, itching or slight swelling. Eye drops may sting briefly. Rarely, blistering or skin irritation occurs. If too much is absorbed, dizziness, ringing in the ears, numb lips or a metallic taste may occur.
Get urgent medical help for swelling of the face or throat, difficulty breathing, widespread rash, seizures, a slow or irregular heartbeat, or confusion after use.
Pregnancy and Lactation
Limited information is available. Short-term use on a small area is unlikely to cause harm, but use in pregnancy or breastfeeding only if a doctor or nurse advises it. Do not apply to the breast before feeding.
Precautions and Warnings
- Numbed areas can be injured without feeling it: protect them until feeling returns.
- After throat numbing, do not eat or drink until normal swallowing returns, to avoid choking.
- After eye numbing, do not rub the eye and protect it from dust.
- Keep cream away from the eyes unless it is an eye product.
Overdose
Too much absorbed tetracaine can cause restlessness, numb mouth, seizures, low blood pressure and heart rhythm problems. Remove any remaining product and get emergency medical help.
Therapeutic Class
Local anaesthetic (ester type).
Storage
Store as directed on the pack; some creams and eye drops must be kept in a refrigerator at 2 to 8°C, others below 30°C. Do not freeze. Keep away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.