ANESTHETIC AGENTS
Anesthetic agents depress the central nervous system causing a loss of con-
sciousness. They are classified as general and local.
Anesthetic agents were introduced in surgery in the early 1800s in the form
of nitrous oxide (laughing gas), which continues to be used today for dental pro-
cedures. Other anesthetic agents became widely used by the mid-1800s. These
included ether and chloroform. Ether is a highly flammable liquid with a pun-
gent odor that causes nausea and vomiting and is seldom used today. Chloroform
is toxic to the liver and is no longer used.
General anesthetics are used for general surgery, cardiac surgery, neuro-
surgery, and pediatric surgery. They are administered by an anesthesiologist or a
nurse anesthetist. They are inhaled through a mask or breathing tube.
A general anesthetic can consist of one medication or a combination of med-
ications—called balanced anesthesia—depending on the patient’s age, weight,
medical history, general health, and allergies.
This balanced approach is used when administering general anesthetics to
patients in phases to minimize cardiovascular problems, decrease the amount of(^276) CHAPTER 15 Nervous System Drugs
Other Barbiturates (continued)
Other Chloral hydrate No hangover and less Pregnancy category C;
Class IV respiratory depression; PB 70%–80%; half life
give with meals or 8–10 hours; PO 250 mg
fluids to prevent tid before meals;
gastric irritation Hypnotic: PO
500 mg–1g h.s.
Other Paraldehyde Exhaled via the lungs; Status epilepticus and
Class IV strong odor and tetanus to control
disagreeable taste; convulsions; Pregnancy
seldom used; has category C, PB UK;
been used to control half life 7.5 hours;
delirium tremens Sedative PO 5–10 mL
(DTS) in alcoholics; q4–6h PRN in water
can be used for or juice; maximum dose
drug poisoning of 30 mL; Hypnotic:
PO 10–30 mL h.s.