Routes of administration of drugs and Posology (Exam 1) Flashcards
2 factors affecting selection of the route of administration
- therapeutic factors
2. drug factors
therapeutic factors
- onset and duration of action
- site of action
- adverse reactions
drug factors
- irritation
- solubility
- pH
routes of administration
- local
2. systemic
local routes of administration
site of administration is where action is
skin, nasal, conjunctival, urethral and bladder, vaginal, rectal, mammary, sublingual, GI tract, otic, epidural, intraspinal, intrasynovial (intra-articular), intramedullary (into bone marrow)
systemic routes of administration
distributed all over the body to reach site of action
- oral (per os, enteral)
- paternal or by injection (IV, SQ, IM, IP)
- inhalation (gases, vapors, aerosols)
What does IP stand for?
Intraperitoneal
advantages of oral administration
- safe
- convenient in some animals
- economical
- no problem of infection
disadvantages of oral administration
- inactivation of some drugs by gastric acidity, digestive enzymes or rumen microflora
- the presence of food may affect absorption
- the presence of drugs may affect absorption
- activity of the GI tract affects absorption
- irritant drugs may cause vomiting and diarrhea
- onset of action is slow
- unpalpability of some drugs
advantages of intravenous
- accurate
- fast onset of action
- irritating, hypertonic, acidic or basic drugs can be given
- large volumes can be given
disadvantages of intravenous
dangerous (leak, overdose, can’t find vein, costly)
advantages of intramuscular (IM)
- rapid absorption
- Duration of action is longer than intravenous
- suspensions can be injected
disadvantages of IM
irritant, hypertonic, acidic or basic drugs may cause tissue damage
advantages of subcutaneous (SQ)
- slow absorption but constant
2. longer duration of action
disadvantages of SQ
- slow onset
2. irritating drugs can not be used
