This section provides a brief overview of the pharmacology of drugs commonly used here at UAF in laboratory animal medicine, animal research, and in wildlife biology.
The drugs described herein are only a fraction of the drugs available and, depending on research objectives and animals being used, use of other drugs may be desirable.
This section is not intended to substitute for reading pharmacology and anesthesia texts but is intended to give you a reasonable starting point. You are expected to read further about the specific drugs that you are using. A true professional understands the pharmacological action of the drugs that he or she is administering. There is much more to anesthesia and animal immobilization then looking up a dose and learning how to get it into an animal!
This section is subdivided into classes or groups of compounds. You should familiarize yourself with the pertinent definitions also available in this module.
Drugs are categorized by class or under "primary use" categories commonly used in anesthesiology textbooks. Drugs presented here only represent those commonly used within UAF studies. For information or advice on drugs not mentioned here you are referred to the many anesthesiology textbooks available or you may contact the UAA Attending Veterinarian.
Tranquilizers:
Sedatives:
- Alpha 2 Agonists
- Alpha 2 Antagonists (not sedatives but these reversal agents are presented here for convenience)
Opioids:
- Agonists , Agonist-Antagonists, Antagonists
Injectable Anesthetic Agents:
- Cyclohexamines (i.e. ketamine and tiletamine)
- Barbiturates
Inhalant Anesthetics:
- Halothane, Isoflurane, Methoxyflurane, Ether , Chloroform, and Others
Generic Name
Common Trade Names
Description
xylocaine Lidocaine Most commonly used local anesthetic at UAF. Comes as xylocaine only but is also availabel with 2% epinephrine. Epinephrine is added to cause local vasocontriction that increases the effective local anesthetic time. However, this combination has been difficult to obtain. Others -caine Any drug ending in the suffix -caine has local anesthetic properties.
PARALYTICS CANNOT BE USED AS THE SOLE AGENT FOR THE CHEMICAL CAPTURE OR RESTRAINT OF ANIMALS!
There are a variety of compounds that cause muscle paralysis by blocking the neuromuscular junction. For our purposes, the most important thing to recognize about these drugs is that they cause immobilization with absolutely no action on the central nervous system. Therefore, although an animal cannot move, it is fully aware of what is going on and there is no analgesia (pain relief). Additionally, paralytics have a low margin of safety and death can occur from paralysis of the muscles needed for respiration (intercostal muscles and diaphragm). For these reasons, use of paralytic agents is restricted to animals under general anesthesia. Any other use of these compounds is considered inhumane. Although there are compounds of historical interest (nictotine, curare) the primary paralytic used is succinyl choline chloride. The discussion that follows refers to this drug.
Legal: Succinyl choline chloride is not controlled.
Indications: For use when muscle paralysis in conjunction with general anesthesia is required. For example, muscle paralysis may be needed during some surgical procedures. However, positive pressure ventilation must be available. May be used as a euthanasia agent only if the animal is already under deep general anesthesia.
Side effects: Low margin of safety. Overdose leads to respiratory failure and death. May affect the heart, particularly if there is already muscle damage. There is muscle soreness upon recovery. May cause bronchospasm, hypotension, salivation, and bronchial secretion.
Absorption, Fate, and Distribution: These drugs are generally fast acting (3-5 minutes) and duration of effect is brief (15-30 minutes). Hydolysed by butyrlcholinesterase in liver and plasma.
Contraindications: Not to be used except for approved protocols when animals are already under general anesthesia and there is an available means of positive pressure ventilation.
Generic Name
Common Trade Names
Description
succinyl choline chloride Sucostrin Anectin
Scoline
Etc.
Inexpensive compound used for muscle paralysis during deep anesthesia. NOT FOR USE AS A SOLE IMMOBILIZING AGENT OR AS A EUTHANASIA AGENT.
Please read about humane euthanasia and review the 2000 REPORT OF THE AVMA PANEL ON EUTHANASIA.
Some inhalant anesthetic agents are used for euthanasia. We use halothane for euthanasia of small birds and rodents. For use of other gases and physical methods of euthanasia you are required to read the 2000 REPORT OF THE AVMA PANEL ON EUTHANASIA and if necessary, the appropriate field guidelines.
Legal: Variable classification from OTC, prescription to scheduled. Keep all euthanasia agents locked up!
Indications: For the humane euthanasia of live vertebrates.
Contraindications/Precautions: Follow instructions carefully. Never use barbiturates for euthanasia unless you can incinerate the carcass. A barbiturate laced carcass can cause substantial mortality in scavengers (fox, bald eagles, etc) if not properly disposed of.
Generic Name
Common Trade Names
Description
pentobarbital Euthasol Beuthanasia
Others
Euthanasia solutions for intravenous or intraperitoneal injection containing multiple substances including pentobarbital (6gr/ml). The mixture of components is designed to cause rapid unconsciousness and death. DO NOT TRY TO USE THESE PRODUCTS FOR RECOVERY ANESTHESIA! These are the preferred compounds for euthanasia of large animals held in captivitiy at UAF. We may anesthetize the animal with ketamine/xylazine or Telazol prior to intravenous injection of one of these compounds.
Can be used for euthanasia in small rodents by intraperitoneal injection.
potassium chloride Potassium chloride is cardiotoxic and will cause the heart to stop following intravenous infusion. However, never administer potassium chloride to an animal unless it is already under deep anesthesia. T-61 A mixture of electrolytes and their salts designed to rapidly render an animal unconscious followed by a rapid death. This compound has no scheduled substances in it therefore did not have the same regulatory issues assocaited with pentobarbtial based euthanasia compounds. No longer available in the USA.
Drugs used in pre-anesthesia (most are dealt with elsewhere)
Tranquilizers
Phenothiazines (not used at UAA)
Sedatives
Parasympatholytic agents
May include atropine or glycopyrrolate to protect the heart and to reduce secretions.
Pain Management
Nonsteroidal Antiinflammatory Drugs (NSAIDs)
Antibiotics
Prophylactic antibiotic usage (see also aseptic technique and surgery in module 3)