Anesthetics

• General anesthesia involves administering drugs to induce unconsciousness or loss of sensation throughout the body.
• Propofol:formulated as an oil-in-water emulsion.

  
• INJECTABLE GENERAL ANESTHETICS: Ketamine

  
• THE LOCAL ANESTHETICS: Cocaine

  
• THE LOCAL ANESTHETICS: Procaine

  
• THE LOCAL ANESTHETICS: Chloroprocaine

  
• THE LOCAL ANESTHETICS: Tetracaine

  
• The local anesthetics-Benzocaine

  
• The local anesthetics-Lidocaine

  
• The local anesthetics- Bupivacaine

  
• The local anesthetics- Levobupivacaine

  
• inhaled anesthetic: Nitrous Oxide

  
• inhaled anesthetic: Halothane

  
• inhaled anesthetic: Methoxyflurane

  
• Inhaled anesthetics:Enflurane

  
• Inhaled anesthetic-Isoflurane

  
• Inhaled anesthetic-desflurane

  
• Inhaled anesthetic-Sevoflurane

  
• Stage 1: Analgesia

  Stage 2: Excitement

  Stage 3: Surgical anesthesia

  Stage 4: Impending death
• The cardiotoxicity of bupivacaine was found to be significantly more prominent with the “R” isomer, or the racemic mixture, thus the “S” stereoisomer is now on the market as levobupivacaine.
• Levobupivacaine is the pure “S” enantiomer of bupivacaine and in vivo and in vitro studies confirm that it does not undergo metabolic inversion to R bupivacaine.
• causes cardiotoxicity?


  Bupivacaine and Levobupivacaine
• Lidocaine , The first amino amide synthesized in 1948 and has become the most widely used local anesthetic.
• Some formulations of lidocaine contain a methylparaben that may cause allergic reactions in PABA-sensitive individuals.
• Benzocaine is a unique local anesthetic because it does not contain a tertiary amine.
• Benzocaine it is uncharged, it is not water soluble but is ideal for topical applications
• Tetracaine was developed to address the low potency and short duration of action of procaine and chloroprocaine
• The addition of the butyl side chain on the para nitrogen increases the lipid solubility of the drug and enhances the topical potency of tetracaine.
• chloroprocaine has a more rapid metabolism than procaine.
• Procaine was synthesized in 1904 to address the chemical instability of cocaine and the local irritation it produced.
• ester hydrolysis produces PABA, the compound responsible for the allergic reactions common to the ester anesthetics.
• Cocaine the first agent used for topical anesthesia.
• Cocaine isolated from the coca leaves that native people of the Andes Mountains chew for multiple effects including local anesthesia and stimulant properties to ward off fatigue.
• The Nitrogen

  -Useful LA have a secondary and tertiary amine form
• -Most of the local anesthetics contain tertiary nitrogen with pKa between 7.5 and 9.5.
• -When the number of carbon atoms in the linker is increased, the lipid solubility, protein binding, duration of action and toxicity increases.
• Linker-Usually an ester or an amide group with hydrophobic chain
• Aromatic Ring- Adds lipophilicity to the anesthetic and helps the molecule penetrate through biological membranes.
• Substituents on the aromatic ring may increase the lipophilic nature of aromatic ring.
• Lipophilic substituents and electron-donating substituents in the para position increased anesthetic activity with ester type local anesthetic.