tetracaine

tetracaine /tet·ra·caine/ (tet´rah-kān) a local, topical, and spinal anesthetic, used as the base or the hydrochloride salt.

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anesthetic [an″es-thet´ik]

1. pertaining to, characterized by, or producing anesthesia.

2. a drug or agent used to abolish the sensation of pain, to achieve adequate muscle relaxation during surgery, to calm fear and allay anxiety, and to produce amnesia for the event.

Inhalational anesthetics are gases or volatile liquids that produce general anesthesia when inhaled. The commonly used inhalational agents are halothane, enflurane, isoflurane, and nitrous oxide. Older agents, such as ether and cyclopropane, are now used infrequently. The mechanism of action of all inhalational anesthetics is thought to involve uptake of the gas in the lipid bilayer of cell membranes and interaction with the membrane proteins, resulting in inhibition of synaptic transmission of nerve impulses. For surgical anesthesia, these agents are usually used with preanesthetic medication, which includes sedatives or opiates to relieve preoperative and postoperative pain and tranquilizers to reduce anxiety. Neuromuscular blocking agents are used as muscle relaxants during surgery. They include tubocurarine, metocurine, succinylcholine, pancuronium, atracurium, and vecuronium.

Intravenous anesthetics are sedative hypnotic drugs that produce anesthesia in large doses. The most common of these are the phenol derivative propofol and ultra–short acting barbiturates such as thiopental and methohexital; these can be used alone for brief surgical procedures or for rapid induction of anesthesia maintained by inhalational anesthetics.

Other intravenous methods of anesthesia are neuroleptanalgesia, which uses a combination of the butyrophenone tranquilizer droperidol and the opioid fentanyl; neuroleptanesthesia, which uses neuroleptanalgesia plus nitrous oxide; and dissociative anesthesia, which uses ketamine, a drug related to the hallucinogens that produces profound analgesia.

Local anesthetics are drugs that block nerve conduction in the region where they are applied. They act by altering permeability of nerve cells to sodium ions and thus blocking conduction of nerve impulses. They may be applied topically or injected into the tissues. The first local anesthetic was cocaine. Synthetic local anesthetics are all given names ending in -caine; examples are procaine and lidocaine.

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tetracaine

a member of the procaine series of compounds. It is a local and spinal anesthetic used in the form of the hydrochloride salt. Can be administered by local injection but is also useful by topical application to conjunctiva, mucosae and skin. Called also amethocaine.