Classification of Anesthesia Pharmacology

Classification of Anesthesia Pharmacology

General Anesthesia :The Drugs from this group are used for Surgical anesthesia. The main effects of general Anesthesia are caused by the inhibition of the intraneuronal (Synaptic) transmission in the CNS The transmission of afferent impulses .

Effects for General Anesthesia – loss of consciousness ,inhibition of sensitivity ( first all pain sensitivity) and reflex  Reactions and the reduction of skeletal muscle tone.  

Classification of General Anesthesia 

1.Inhalation Anesthesia 

1.Liquid volition drugs

• Halothane ( phthorothanum)
• Isoflurane
• Enflurane
• Diethyl ether

2.Gaseous Drugs

• Nitrous drugs

2.Non inhalation (intravenous) anesthesia 

• Propanidid
• Propofol
• Thiopental
• Hexobarbital (Hexenal)
• Sodium Hydroxybutyrate
• Ketamine

Non inhalation (intravenous) anesthesia  (Short Action -anesthesia duration is 15 min)

• Propanidid
• Propofol
• Ketamine

Non inhalation (intravenous) anesthesia  (Medium Action -anesthesia duration is 20-30 min)

• Thiopental
• Hexobarbital (Hexenal)

Non inhalation (intravenous) anesthesia  (Long Action –anesthesia duration is 60 min and more)

• Sodium Hydroxybutyrate

Local Anesthesia : Local anesthetic drugs (anesthesia) cause local Sensory loss. They eliminate painful sensation and and this why they  are mainly used for local pain relief (anesthesia).

Temperature and other type of sensation are blocked, with touch and pressure reception being the last to go.

The Mechanism of action of anesthetics is mainly based on Voltage dependent sodium channel blockade. This prevents both the appearance  and conduction of the action potential.

Classification of Local Anesthesia

1.Drugs used for topical (surface) anesthesia

• Cocaine
• Tetracaine
• Benzocaine
• Bumecaine

2.Drugs mostly used for infiltration and regional anesthesia

• Procaine  Bupivacaine

3.Drugs used for all types of anesthesia

• Lidocaine
• trimecaine

Hypnotics Drugs

Hypnotics facilitate falling asleep and provide necessary sleep duration. The Traditional hypnotics the have been used for long time. are drugs of non-selective depressant  action on the CNS.

In Low doses they have a sedative effects , in medium doses hypnotic effect and high doses – an anesthetic one. They are not used for General Anesthesia due to their narrow margin of safety  and long term action  that make it impossible to control the depth of the General Anesthesia.

Classification of Hypnotics

Hypnotics drugs are classified according to the Principle of the action and Chemical Structure

1.Hypnotics Drugs-agonists of benzodiazepine receptors

1.Benzodiazepine Derivatives

• Nitrazepam
• Lorazepam
• Nozepam
• Temazepam
• Diazepam
• Phenazepamum
• Flurazepam

2.Drugs of different chemical Structure (Non Benzodiazepine Compound)

• Zolpidem
• Zopiclone

2.Hypnotics Drugs Non-Selective CNS Depressants

1.Hetrocyclic Compound

*Derivatives of barbituric acid (barbiturates)

• Pentobarbital (ethaminal, nembutal)

2.Aliphatic Compound

• Chloral hydrate

Pain Reliving Drugs ( Analgesics)

An analgesic drug, also called simply an analgesic, pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain. It is typically used to induce cooperation with a medical procedure.

Pain may be also cause by a dysfunction of the Nervous System itself .These is so called neuropathic pain ,associated with direct injury of peripheral nerves or cerebral tissue  due to ischemia, infection, tumor growth , etc.

Elimination or relief of pain by means of analgesics leads to the improvement in physical and psychological condition of the patient and therefore , favorably affects their Professional and social life.

Classification of Analgesics

1.Drugs of mainly central action

1.Opioid (narcotic) analgesics, 

• Agonists
• Agonists -antagonists and Partial agonists

2.Non- opioid analgesics

• Non-opioid (non-narcotic) analgesics (Para aminophenol Derivatives )
• Drugs from different pharmacological groups with analgesic component of action

2.Drugs of mainly peripheral action

Non-opioid (non-narcotic) analgesics (Derivatives of salicylic acid, Pyrazalone)

1.Opioid (narcotic) analgesics and Antagonists

1.Agonists

• Morphine
• Trimeperidine (Promedolum)
•  Fentanyl
• Sufentanil

2.Agonists -antagonists and Partial agonists

• Pentazocine
• Nalbuphine
• Butorphanol
• Buprenorphine

Most opioid analgesics belong to the first group of drugs. However , agonists-antagonists can also be used as analgesics if they predominantly have agonist properties. Partial agonists cane be used as well.

Morphine : The main effects of morphine is pain-relief .Morphine has a rather selective pain-relieving action. It does not depress other type of Sensitivity ( Touch, temperature, hearing, sight ) in the therapeutic doses.

Neuroleptics , Anxiolytics Drugs ……………