2. Agenda
2
I. Intravenous Induction Drugs
a. Indications
b. Dosage
c. Effects
II. Inhalational Drugs
a. Indications
b. Dosage
c. Effects
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
3. Agenda
3
III. Muscle Relaxants
a. Indications
b. Dosage
c. Effects
IV. Analgesia
a. Opioids
a. Indications
b. Dosage
c. Effects
V. Adjuvants to Anesthesia
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
4. I. Intravenous Induction Drugs
4
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
5. Intravenous Induction Drugs
5
• Ketamine
• Propofol
• Thiopentone
INCLUDES:
DEFINITION
Intravenous anesthetic drugs can be used for induction and
maintenance of anesthesia
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
6. Intravenous Induction Drugs
6
KETAMINE
• Induction & maintenance of anesthesia
• Can be used as sole anesthetic agent
• Agent of choice in hypotensive/shocked patients
• Maintains respiratory & cardiovascular stability
• Good for short procedures
• Analgesic properties
• Increases secretions & lowers seizure threshold
• Causes emergence phenomena
• Dosage:
1-2mg/Kg IV 5-10mg/Kg I.M 0.2-0.5mg/Kg
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
7. Intravenous Induction Drugs
7
PROPOFOL
• Whitish, milk-like emulsion, containing
10mg/ml of propofol
• Causes More Cardiorespiratory
depression
• Gives a smooth induction, maintenance
and emergency from anesthesia
• Dosage: 2-4mg/kg IV induction
• Caution in egg, soya and nut allergies
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
8. Intravenous Induction Drugs
8
THIOPENTONE
• Whitish powder
• Must be reconstituted & given as 2.5%
solution intravenously
• Fast onset of action ideal for RSI
• Causes less cardiorespiratory
depression than propofol
• Risk bronchospasms, contraindicated in
asthmatics
• Has anticonvulsant properties
• Dosage: 3-5mg/Kg IV Induction
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
10. Inhalational Drugs
10
• Halothane
• Isoflurane
• Sevoflurane
INCLUDES:
DEFINITION
Inhalational anesthetic drugs can be used for induction and
maintenance of anesthesia
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
11. Inhalational Drugs
11
GENERAL INFORMATION
• Induces anesthesia following inhalation
• Causes unconsciousness
• Unknown mechanism of action
• Potency depends on MAC
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
12. Inhalational Drugs
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MAC VALUES
Nitrous Oxide 105.00
Halothane 0.75
Isoflurane 1.20
Sevoflurane 2.00
Desflurane 6.00
Minimum Alveolar Concentration (MAC)
• Minimum alveolar concentration required to prevent reaction to a
standard surgical incision in 50% of patients at steady states
• The lower the MAC, the more potent the agent
• Different agents have varying MACs and other physical properties
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
13. Inhalational Drugs
13
HALOTHANE
• Highly potent inhalation, used for induction
& maintenance of anesthesia
• Sweet smelling - an ideal agent for
gaseous induction
• Causes significant cardiorespiratory
depression
• Risk of arrhythmias, especially when used
concurrently with adrenaline
• Beware of deep halothane anesthesia in
children
• Hepatotoxic following repeated exposure
• Potent bronchodilator, useful in asthmatics
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
14. Inhalational Drugs
14
ISOFLURANE
• Widely used for maintenance of
anesthesia
• Unpleasant, pungent smell - not
recommended for gaseous induction
• Respiratory depressant
• Less myocardial effect but there is
compensatory tachycardia due to
decrease in SVR
• Increasingly becoming common
• Safer than halothane
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
15. Inhalational Drugs
15
SEVOFLURANE
• Among the modern inhalational
agents
• Expensive
• Has a better safety profile than
halothane
• Sweet odor - well tolerated as an
induction agent
• Predictable respiratory depression
• Myocardial sparing, but may cause
hypotension due to fall in SVR
• Gives a smooth induction and rapid
emergence
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
17. Muscle Relaxants
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• Suxamethonium
• Pancuronium
INCLUDES:
DEFINITION
Muscle relaxants are drugs affecting skeletal muscle function
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
18. Muscle Relaxants
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• Relaxes skeletal muscles
• Facilitates tracheal intubation, ease of ventilation and
provides optimal surgical operating conditions
• Neuromuscular blocking drugs (NMBDs) are grouped into
two:
• Depolarizing (e.g. suxamethonium)
• Non-Depolarizing (e.g. pancuronium, atracurium, rocuronium,
Vecuronium)
• Most commonly used are suxamethonium, pancuronium and
atracurium
GENERAL INFORMATION
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
19. Muscle Relaxants
19
SUXAMETHONIUM
• The only depolarizing NMBD
• Principally used for induction
• Ideal for RSI due to its rapid onset of action
• Given in a dose of 1-2mg/kg IV
• Side effects include:
• Muscle pain
• Bradycardia
• Hyperkalemia
• Anaphylaxis
• Malignant Hyperthermia
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
20. Muscle Relaxants
20
PANCURONIUM
• Long acting NMBD
• Muscle paralysis to facilitate such surgery
• Can be used for tracheal intubation in
elective cases
• Given in a dose of 0.02-0.04mmg/kg IV
• Reversal of paralysis usually required with
an anticholinesterase
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
22. ANALGESIA
22
ANALGESIA
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
• Key component of balanced anaesthesia
• Pain is generally poorly managed in most cases of GA
• Multimodal approach should always be considered:
• Opioids – e.g. pethidine, fentanyl, morphine, tramadol
• NSAIDS – diclofenac IV/IM/suppository
• Paracetamol – IV/suppository
• Ketamine – IV/IM
• Regional block
• Local wound infiltration – e.g. bupivacaine, lignocaine
23. OPIOIDS
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• Potent and strong analgesic drugs known
• Used to treat moderate to severe pain
• Includes: morphine, pethidine, fentanyl, alfentanyl, ramifentanyl
and sufentanyl
• Effects:
• Analgesia, sedation
• Addiction, tolerance
• Respiratory depression
• Cardiovascular suppression
• Constipation
GENERAL INFORMATION
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
24. OPIOIDS
24
PETHIDINE
• Commonly used opioid in low
resource settings
• Used to treat moderate to severe
pain
• Can be given IV, IM ,SC
• Given in a dose of 1-2mg/kg up to a
max of 400mg/day
• Can cause respiratory depression,
cardiovascular suppression, allergic
reaction
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
25. OPIOIDS
25
MORPHINE
• Naturally occurring (found within the opium poppy)
• Standard opioid against which all other opioids are
compared
• Long acting opioid
• May be used to provide sedation, additive for
epidural/spinal anesthesia
• Given in a dosage of 0.05-0.1mg/kg IV
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
26. OPIOIDS
26
FENTANYL
• Synthetic opioid
• 100 times more potent than morphine
• Can be given IV, IM, SC, PO, Intrathecally
• Some of the uses include: analgesic,
added to LA in spinal anesthesia, patches,
obtund reflexes during laryngoscopy
• Given in a dose of 1-2mcg/kg IV
• Like other opioids, it’s a potential
cardiorespiratory depressant.
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
27. V. ADJUVANTS TO ANESTHESIA
27
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
28. ADJUVANTS TO ANESTHESIA
28
ADJUVANTS
UAM Simulation-based Training I Lecture Content | Anesthesia Pharmacology
• Vasopressors-should always be available and drawn up for emergency
purposes (e.g. adrenaline in 10mcg/ml and 100mcg/ml concentrations)
• Antisialogogue: e.g. atropine and glycopyrrolate: not given as routine unless
indicated
• Anxiolytics: Benzodiazepines (e.g. diazepam, midazolam) may be
administered as premedication for anxious patients
• Antiemetics: for postoperative N&V (e.g. dexamethasone ondansetron,
metoclopramide)
