Altacaine

Altacaine is a local anesthetic (LA) which upon topical application causes reversible loss of sensory perception, especially of pain in a restricted area of the body. It blocks generation and conduction of nerve impulse at any part of the neuron with which it comes in contact, without causing any structural damage. As a result, no pain sensation takes place.

Although it is both surface and conduction block anesthetic, its use is restricted to topical application to the eye, nose, throat, tracheobronchial tree and rarely for spinal or caudal anesthesia of long duration.

Tetracaine is mainly used in ophthalmology before some medical procedures such as tonometry, gonioscopy, removal of corneal foreign bodies etc. It is used in minor surgical procedures and usually, it is not prescribed to use at home, but sometimes this medicine is prescribed to use as antipruritic agent.

Before using Altacaine, you must know all about the risks and complications associated with it. Each and every time, the risks of taking a drug should be kept in mind. Here, both the doctor and the physician take part to make a decision for choosing a drug. The risk and benefit ratio should be considered before starting a drug therapy.

If you have had any allergic reactions to any medicine, then you must inform your doctor about that. Always be free to tell your physician if you have any heart diseases or respiratory problems like bronchial asthma. You should be more careful before administration of such preparation because it may cause severe eye irritation.

Moreover, serious reactions may take place when it is used with another. Concurrent use of vasoconstrictors (e.g. adrenaline) prolongs the duration of action of LA by decreasing their rate of removal from the local site when you are receiving tetracaine eye drops, which increases the chances of subsequent local tissue edema and necrosis as well as delays wound healing by reducing oxygen supply and enhancing oxygen consumption in the affected area. Additionally, it may raise blood pressure and promote arrhythmia in susceptible individuals.

The clinically used local anesthetics have no or minimal local irritant action and block sensory nerve endings, nerve trunks, neuromuscular junction, ganglionic synapse and receptors. They also reduce release of acetylcholine from motor nerve endings. As a result, paralysis of the voluntary muscles supplied by that nerve may also occur but rarely.

Local anesthetic like tetracaine often fails to afford adequate pain control in inflamed tissue.

The most likely reasons are:

• Blood flow to the inflamed area is increased, that’s why tetracaine or other local anesthetic is removed more rapidly from the site.
• Inflammation lowers pH of the tissue resulting in greater fraction of the local anaesthetic like tetracaine becomes inactive as it is in the ionized form hindering diffusion into the axolemma.
• Certain inflammatory products produced by the cells may oppose the anesthetic action of tetracaine.

Altacaine, an ester-linked local anesthetic has less intense analgesic effect because of its short duration of action. For this reason, it is rarely used for infiltration or nerve block, but still used topically on mucous membranes. Actually, this drug is used by an ophthalmologist to cause numbness or loss of feeling before surgery or medical tests.

This eye preparation is commonly given to the patients directly in the eye by a nurse or other trained health professional under the direct supervision of an ophthalmologist.

In case of self or home usage, clean hands should be ensured before administration. Try to take the drug as prescribed by your physician.

Before using Altacaine, there are some precautions you must take.It is always better to remain ready to face any undesired effects after taking any drug.

Some important measures should be taken if you feel any discomfort after administration of such medication into your eye.

• Firstly, you have to stop using this drug and then consult with your physician immediately.
• In case of children, be careful not to exceed the maximum safe dose.
• You should not take certain medicines during this drug therapy. It is safe to consult with your doctor if you are in need of some drugs for another health problem.
• Beta-blockers like propanolol may reduce the metabolism of tetracaine or other local anesthetics by reducing hepatic blood flow, which causes decreased effectiveness of tatracaine.
• Vasoconstrictor (e.g. adrenaline) containing local anesthetic should be avoided for patients with ischemic heart disease, cardiac arrhythmia, thyrotoxicosis, uncontrolled hypertension, and those receiving beta-blockers or tricyclic antidepressants.

As with many medications, there are several potential side effects associated with Altacaine. Sometimes, you may need to consult with the doctor if you feel any discomfort like blurred vision, trembling or shaking of the limbs, chest pain or discomfort, feeling of irregular heart beat etc.

Usual side effects need no medical attention, but in some conditions may demand emergency resolution as in unconsciousness or seizure. However, toxicity after topical application or regional injection is influenced by the relative rates of absorption and metabolism.

You should seek medical help when the following problems become significant –

• Cardiovascular toxicity of tetracaine is manifested as bradycardia, hypotension, cardiac arrhythmias and vascular collapse.
• Problems affecting central nervous system (CNS) are light-headedness, dizziness, auditory and visual disturbances, mental confusion, disorientation, shivering, involuntary movements, finally convulsions and respiratory arrest. This can be prevented and treated by diazepam.
• Hypersensitivity reactions like rashes, angioedema, dermatitis, contact sensitization, asthma, and rarely anaphylaxis may occur.
• Often methylparaben added as preservative in certain local anesthetic solutions is responsible for the allergic reaction.