ROUTES OF ADMINISTRATION

• Enteral routes


  Involves drug administration via the gastrointestinal tract
• Parenteral routes


  Refers to routes of administration that bypass the GIT
• Enteral routes


  • Oral
  • Sublingual
  • Rectal
• Oral route


  • Most convenient for the client/pet owner
  • Less likely to cause adverse reactions
  • Sterility of drugs is not critical
• Administration of solid oral dosage form in the dog

  Use a pilling gun with a flexible rubber end to hold the solid dosage form and a plunger to deliver the pill to the back of the throat
• Administration of solid oral dosage form in the cat

  Use a pilling gun with a flexible rubber end to hold the solid dosage form and a plunger to deliver the pill to the back of the throat
• Drenching in ruminants

  Administer a large oral dose of liquid medicine
• Rectal route

  • Practical route for antiemetics, anticonvulsants and antibiotics in animals
  • Lower rate and extent of drug absorption vs. the oral route
  • Local irritation is possible with rectally-administered drugs
• Parenteral route


  Usually pertain to the injection route
• Most common injection routes in animals

  • Intravenous
  • Intramuscular
  • Subcutaneous
• Parts of a syringe

  • Plunger
  • Barrel
  • Flange
  • Tip
  • Hub
  • Shaft
• Injections are done with the needle bevel up
• Intravenous route

  • Drug is administered within the vein
  • Most IV-administered drugs are aqueous solutions; a few are emulsions
  • The injected drug must be pure, sterile and free of particles
• Advantages of IV route

  • Rapid onset of action
  • Larger volumes can be given
  • Irritating drugs that are painful via other routes can be given IV
  • Predictable drug concentration is achieved in the blood circulation
• Disadvantages of IV route

  • Increased risk of adverse effects (if drug is rapidly administered, not sterile, or improperly mixed)
  • Perivascular administration may inadvertently occur when giving drug IV
• IV administration techniques

  1. IV bolus administration

  2. Intermittent IV therapy

  3. Continuous infusion
• Intramuscular route

  • The drug is administered within the skeletal muscle
  • The drug should be in aqueous solution or suspension, oily suspension
  • Absorption rate depends on formulation (oil-based is slow)
  • Aspirate the syringe check if the needle did not hit a blood vessel
• Advantages of IM route

  • Relatively rapid onset of action (30 min)
  • Provides reliable blood levels
  • Convenient route for fractious animals
• Disadvantage of IM route


  • IM injections may cause pain
• Subcutaneous route


  • The drug is administered into the connective tissue underneath the skin dermis
  • The absorption rate of the drug would depend on the formulation
• Advantages of SC route

  • Can be used for giving larger volumes of solutions
• Disadvantages of SC route

  • May lead to less reliable blood levels of drug
  • Not for irritating or hyperosmotic solutions
• The angles of needle insertion vary for IM, SC, IV and ID routes
• Other parenteral routes


  • Intraperitoneal
  • Intramedullary/intraosseus
  • Intra-arterial
  • Inhalation
• Other routes


  • Intradermal
  • Intracardiac
  • Intra-articular
  • Intramammary
  • Vaginal
  • Epidural/subdural/intrathecal
• Topical route


  • Drug is applied on skin surface or mucous membranes
  • The drug is applied or placed directly on where its site of action is desired
  • Good skin contact may be inhibited by animal's fur or feathers
• Topical routes


  • Otic
  • Ocular
  • Transdermal