Halothane is a volatile liquid inhalation anesthetic that was commonly used to induce and maintain general anesthesia in both veterinary and human medicine. It has a rapid onset and offset of action, allowing for quick induction and recovery from anesthesia. However, it has been largely replaced by newer agents due to risks like malignant hyperthermia and hepatic toxicity. This document provides details on the physical and chemical properties, pharmacokinetics, dosing, uses, and adverse effects of halothane.

1. HALOTHANE
Submitted by,
Vysakh Mohan M
13-BVM-42

2. HALOTHANE
INTRODUCTION
• General anaesthetic
• Volatile liquid inhalation anaesthetic
• Molecular formula – CF3CHClBr
• IUPAC Name – 2-bromo-2-chloro-1,1,1-
trifluoroethane
• Brand Name – Fluothane
• Induction and maintenance anaesthetic agent

3. HALOTHANE
PHYSICAL AND CHEMICAL PROPERTIES
• Volatile Heavy liquid (Specific gravity – 1.87)
• Boiling point – 50.20C
• Vapour pressure – 243 mmHg at 200C
• Molecular Weight – 197.4 u
• Decomposes when exposed to light (Amber
coloured bottles and addition of thymol)
• Non-explosive and non-inflammable

4. HALOTHANE
MINUMUM ALVEOLAR CONCENTRATION/MAC*
• Dogs – 1.87
• Cats – 1.19
• Cattle – 0.76
• Horses – 0.88
• Humans – 0.76

5. HALOTHANE
DOSE
• Induction (Halothane alone)
– All species : 2.0 – 4.0% (of inspired air)
• Maintenance (Halothane alone)
– Small animals : 0.5 – 1.5%
– Large animals : 1.0 – 2.0%

6. HALOTHANE
PHARMACOKINETICS
• Rapidly absorbed and rapidly excreted
through lungs
– 20% : Biotransformation in liver and excreted
through lungs
– 60% : Excreted unchanged through lungs
– 20% : Excreted via other routes, either unchanged
or metabolised and stored in body for many hours
to days

7. HALOTHANE
ADVESE EFFECTS
• Vasodilatation, hypotension, shivering and
tremors on recovery
• Malignant hyperthermia
• Cardiac arrhythmias
• Cardiopulmonary depression and cardiac
arrest

8. HALOTHANE
CONTRAINDICATIONS AND PRECAUTIONS
• Not used for pig breeds like Poland China and
Pietrain
• Used with caution in animals with increased
CSF, head injury, etc.
• Not used in animals having problems after
previous halothane exposure

9. HALOTHANE
CLINICAL USES AND ADMINISTRATION
• Capable of induction and maintenance of
anaesthesia without assistance from other
CNS depressants
• Used in a closed rebreathing system with
precision thermo-stable or thermo-
compensated, calibrated vapourisers
• Open and semi-open systems are used only in
case of very small dogs, cats and laboratory
animals

10. HALOTHANE
RELATED SUBSTANCES
• Enflurane, isoflurane and sevoflurane.
• Incidence of hepatic reaction with these
agents is lower
• Lower blood solubility resulting in faster
induction of and recovery from anaesthesia

11. HALOTHANE
AVAILABILITY
• Available as a volatile liquid,
at 30, 50, 200, and 250 ml per
container
• In many developed nations is
not available having been
displaced by newer agents.

12. REFERENCES
• Veterinary Pharmacology and Therapeutics –
Harpal Singh Sandhu
• Veterinary Anaesthesia and Pain Management
Secrets – Stephen A Greene
• Wright’s Veterinary Anaesthesia and Analgesia –
L W Hall
• Veterinary Anaesthesia – William V Lumb and E E
E Wynn Jones
• http://www.drugs.com/pro/Halothane
• http://en.wikipedia.org/wiki/Halothane