DRUG DISPOSITION AND FATE OF DRUGS Flashcards
Two types of Drugs
Water Soluble
Lipid Soluble
Advantages of ORAL ADMINISTRATION
Convenient
Cheap
No need for sterilization
Variety of dose forms
Disadvantages of ORAL ADMINISTRATION
Variability due to physiology, feeding, disease, etc.
Intractable patients
First-pass effect
The bolus remains relatively spherical
Liquid soluble Vehicle
Advantages of Subcutaneous Administration
Can be given by the owner(small patients)
Vasoconstrictor can be added to prolong effect at site of interest
Disadvantages of Subcutaneous Administration
Variability
Patient and pharmaceutical Factors
More autonomic control over blood flow
Dehydration, heat, cold, stress
Advantages of Topical
If systemic theraphy-easy painless application
If skin therapy- reduced systemic effects/enhanced skin effects
Disadvantages of Topical
Patients groom themselves(topically applied, orally absorbed)
Toxic skin reactions
Variable blood flow to skin
COMPLEX relationship between drug, vehicle, skin physiology
Process of Topical
Diffusion through stratified epithelium
“Passage” through adnexal structures
Patient and pharmaceutical Factors of Topical
Lipid solubility and molecule size
Skin dehydration and abrassion
Area of application
Ambient an patient temperature
Vehicle effects
“like” vehicles retain drug on skin surface
“ unlike” vehicles leave the vehicle to move on to skin
Advantages of intraperithoneal
Larger absorptive surface are than IM/subcutaneous
Disadvantages of Intraperitoneal
Drugs or vehicles may cause peritonitis
Damage to organs by needles
Injection into organs
Process of Intraperitoneal
Similar to subcutaneous
Greater blood flow
Less flow regulation
