pharmacology

Lecture 1
Pharmacokinetics
Pharmacokinetics refers to what the body does to a drug, whereas pharmacodynamics
describes what the drug does to the
body. Four pharmacokinetic properties determine the onset, intensity,
and the duration of drug action
• Absorption: First, absorption from the site of administration permits
entry of the drug (either directly or indirectly) into plasma.
• Distribution: Second, the drug may then reversibly leave the bloodstream
and distribute into the interstitial and intracellular fluids.
• Metabolism: Third, the drug may be biotransformed by metabolism by
the liver or other tissues.
• Elimination: Finally, the drug and its metabolites are eliminated from
the body in urine, bile, or feces.
Using knowledge of pharmacokinetic parameters, clinicians can design
optimal drug regimens, including the route of administration, the dose,
the frequency, and the duration of treatment.
ROUTES OF DRUG ADMINISTRATION
A. Enteral
B. Parenteral
C. Other
ABSORPTION OF DRUGS
Absorption is the transfer of a drug from the site of administration to the
bloodstream. The rate and extent of absorption depend on the environment
where the drug is absorbed, chemical characteristics of the drug,
and the route of administration (which influences bioavailability). Routes
of administration other than intravenous may result in partial absorption