tetracaine

Tetracaine is a local anesthetic belonging to the ester class. It is primarily used in medicine and dentistry to numb areas of the body. It works by reversibly blocking nerve signal transmission. This blockage is achieved by inhibiting the influx of sodium ions into nerve cells, which is essential for the generation and propagation of action potentials.

Medically, tetracaine is most commonly encountered as an ophthalmic solution used for topical anesthesia of the eye. This allows for procedures such as tonometry, gonioscopy, and the removal of foreign bodies without causing pain to the patient. It is also used in some nasal sprays for topical anesthesia in otolaryngology procedures.

In the past, tetracaine was also used for spinal anesthesia, but it has largely been replaced by other agents with a more predictable duration and fewer side effects. As an ester anesthetic, tetracaine is metabolized in the plasma by pseudocholinesterase, leading to its elimination. Allergic reactions, though uncommon, can occur, especially with repeated exposure. Overdose symptoms can include central nervous system excitation or depression, cardiovascular effects, and respiratory distress. Due to its potential for systemic absorption and adverse effects, it should be administered with caution and under appropriate medical supervision.