GPAT Study Material related to Pharmacology of General and Local Anesthetics

This Study Topic is also helpful for Other Competitive
Exams like PGCET, GATE etc....

Pharmacology of General and Local Anesthetics :

- General Anesthetics in Hospital Context


   Combination of inhaled gases, IV and IM


   Synergistic effects allow use of less meds

- Pre-hospital Context at associated with RSI for Intubation or analgesia


- Overton-Meyer theory - “The greater the solubility in lipids, the greater the effect”


- Nerve Cells have high lipid content
 
 
Types of Anesthetics :
 
- Inhalation- volatile gases or liquids vaporized in oxygen



   Prehospital - Nitrous Oxide


-  Intravenous- adjunctive agents

                Induction -- Opioids - Fentanyl


                Amnesiac -- “Benzos” - Valium, Versed


                Anticholinergic -- Atropine


                Pain control -- Opioids - MS, Demerol


                Amnesia / Sedation -- Vistaril, Phenergan
 
 
Side / Adverse Effects of  General and Local Anesthetics :
 
- Halogenated gases may cause hepatotoxicity



- Nitrous Oxide may cause sedation (usually self limited due to self administration)


- Opioid side effects (Respiratory, Cardiac depression
- Malignant Hyperthermia


Toxicity of  General and Local Anesthetics :


- Most agents have short half-life



- Used in controlled circumstances with ACLS - trained personnel present


- Nitrous Oxide self limiting


- Antagonists -- Narcan of Opioids, Romazicon for Benzodiazepines


- Succycholine -- short half-life (15 min)
 
 
Action of Local Anesthetics :
 
- Block conduction and sensation in nerve fiber



- Epidural, infiltration, nerve blocks, spinal, and topical


- Used in Dental procedures, suturing, spinal anesthesia and diagnostic procedures


- “Caines”, ethyl chloride, dyclonine