Routes of Drug Administration

1
Routes of Drug Administration

• I.M. (intramuscularly)
• Use at least a one inch needle to assure that the
  drug is placed deep in the muscle for proper
  absorption.
• The diameter or gauge (g) of the needle should be
  as small as possible to prevent the drug from
  running up the needle tract and down the side of
  the animal.
• This route allows for the second fastest rate of
  absorption
• Site of injection is important, particularly in
  food producing animals, when possible use the
  muscles in the neck. Injection site abscesses can
  develop.

2

• I.V. (Intravenous)
• Provides the fastest route of absorption of the
  drug
• In large animals use a 1.5 inch X 16g needle
• In large animals the jugular vein in the neck is
  most often used
• Always read the label, some drugs cannot be
  administered I.V.
• Drugs should be close to body temperature before
  administration
• Drugs should be administered slowly (drip) when
  given I.V.

3

• Sub-Q (subcutaneous)
• Drug administered between the skin and muscle
• Injections or implants
• Provides for a slower , sustained release of the
  drug
• Less likelihood of causing tissue damage at the
  injection site in food producing animals
• Can cause permanent knots that disfigure the
  animal, sometimes lessening its value.

4

• I.D. (intradermal)
• Drug injected into the skin
• Very slow rate of absorption
• Ex. Tuberculosis skin test
• Use 20 to 26g needle

5

• I.P. (intraperitoneal)
• Drug injected directly into the peritoneal cavity
• Slow absorption rate
• In large animals a 1.5in X 16g needle I generally
  used
• Often used in combination with I.V. injections to
  prolong the availability of the medication to the
  animal ex. Milk fever- Cal-Dex given both I.V.
  and I.P.

6

• I.R. (intrarumenal)
• Similar to I.P. ,but into the rumen (1st stomach
  in ruminant animals)
• When the needle is properly placed gas wiil flow
  out
• Can only be accomplished on the left side of the
  animal

7

• I.M.F. (intramammary infusion)
• Drug is injected into the teat canal using a
  plastic teat infusion canula
• Used in the treatment of mastitis

8

• I.N. (intranasal)
• Drug is squirted up the nostril
• Some vaccines can be administered this way ex.
  Nasogen for IBR vaccination
• Many pharmaceutical companies are currently
  developing vaccines and other drugs that can be
  administered I.N. to avoid injection site
  problems and to satisfy animal rights activist.

9

• I.U. (intrauterine infusion)
• Drug in infused into the uterus by passing a
  pipette through the cervix
• Often used to treat metritis (uterine infection)

10

• Topical
• Drug applied to the skin or surface of the body
• ex. Salves, ointments, pour-on wormers, dusts,
  etc.

11

• Oral (drench)
• Drug administered through the mouth in the form
  of a bolus (pill) or liquid
• Liquids or pastes can be placed in the mouth and
  the animal allowed to swallow them or a stomach
  tube can be used to place the drug directly in
  the digestive system