Routes Of Administration And pharmacokinetics Flashcards
What is pharmacokinetics?
-what the body does with a drug
-the movement of a drug through the body
What is pharmacodynamics?
-what a drug does to the body
-the body’s response to the drug
What is ADME?
Absorption, Distribution, Metabolism, Elimination
Site of absorption for oral drugs ?
Mouth / Gi tract (gastrointestinal)
Site of absorption for respiratory tract?
Nasal passages or lungs
Intravenous (IV) site of absorption ?
Directly into venous blood
Intramuscular site of absorption ?
Muscles
Buccal (cheeks, teeth, gums) site of absorption?
Oral mucosa
Transdermal (patches, gels, gums) site of absorption?
Skin
What is the Gi tract?
The gastrointestinal tract, a series of hollow organs joined in a long tube
What is in the GI tract?
Mouth, oesophagus, stomach , small intestine, large intestine, anus
What is drug absorption?
The movement of drugs into the blood stream
Modes of transport for drug absorption?
-Filtration through pores
-passive diffusion through membrane
-active transport
-facilitated diffusion
-phago/pinocytosis
What is active transport?
The movement of particles against the concentration gradient using energy (atp)
What is passive transport?
The movement of particles along the concentration gradient without energy
The path of drug absorption (oral)
GI tract - liver - right heart - lungs - left heart - arterial circulation
Drug absorption path (inhalation)
Lungs -left heart -arterial circulation
Factors that affect drug distribution?
-rate of distribution
-membrane permeability
-blood perfusion
What is bioavailability ?
The fraction of drug that reaches systematic circulation in an unchanged form
What is bio transformation?
Biochemical modification or degradation through specialised enzymatic actions
What is phase 1 in metabolism?
Non-synthetic reactions which can lead to either the activation or inactivation of the drug
What is phase 2 metabolism?
Conjugation or synthetic reactions
3 methods of elimination?
-pulmonary -air
-bile- faeces
-renal -urine
What is the hepatic portal system?
The hepatic portal system is a series of veins that carry blood from capillaries the stomach, intestine, spleen and pancreas to capillaries in the liver. Main function is to deliver deoxygenated blood to the liver to be detoxified before taken back to the heart
What is drug half life ?
The time taken for the concentration of the drug in blood to fall by half
Common drug tests?
Blood , urine and hair
Equation for the estimation of blood alcohol concentration ?
(Total alcohol consumed - amount of alcohol metabolised ) / volume of distribution
