Exam 1 Terms Flashcards
Topical Route of Drug Administration
Dermal, Intranasal, Mucous Membrane, Eyes
Enteral Route of Drug Administration
Buccal, Sublingual, Oral, Rectal
Parenteral Route of Drug Administration
Intravenous, Intramuscular, Subcutaneous, Transdermal, etc.
Membrane proteins that control the influx of essential nutrients and ions and the efflux of cellular waste, environmental toxins, and drugs.
Transporters
Include Organic Anion Transporting Polypeptides (OATPs), Organic Anion (OATs), and Organic Cation (OCTs) transporters.
SLC (Solute Carrier)
Active transporters that rely on ATP Hydrolysis to actively pump their substrates across membranes.
ABC (ATP Binding Cassette)
Pharmaceutical factors involved in GI absorption via passive diffusion.
Solubility/Concentration, Stability, and Controlled Release Preparations
Chemical properties of drugs involved in GI absorption via passive diffusion.
Molecular Size, Lipid Solubility, and Ionization Coefficient (pKa)
Drugs that cross membranes by passive diffusion tend to accumulate in compartments where the degree of ionization is the greatest.
Ion Trapping
Relates the amount of drug in the body to the concentration of drug in the vascular compartment.
Volume of Distribution (Vd)
Normal Vd in the vascular compartment.
3-5 L
Normal Vd in the extracellular compartment.
10-20 L
Normal Vd in the total body water compartment.
35-50 L
Important plasma proteins for drug binding.
Albumin (acidic drugs), Alpha1 Acid Glycoprotein (basic drugs), Lipoproteins, Specific hormone carrier proteins
Consequences of drug binding to plasma proteins.
Reduces the concentration of unbound drug, may slow the distribution and elimination of the drug (depot), and represents a potential site of drug interaction.
There is an increased risk of an adverse drug reaction (ADR) with:
Increased protein binding, decreased Vd, and decreased elimination kinetics.
Reaction that results in relatively minor chemical modification of the parent compound.
Phase I Reaction; metabolite more polar
These reactions are conjugations.
Phase II Reaction; metabolites are pharmacologically inactive
Enzyme located in liver and several other organs that oxidatively metabolizes most drugs.
Cytochrome-P450; localized in the sER; dependent on NADPH and molecular O2; low degree of specificity
Quantitatively most important phase II reaction.
Glucuronidation
Type of drugs that can be secreted by the liver into the bile (Biliary-fecal route).
Amphipathic, lipid-soluble conjugated metabolites, with a MW > 300
Enterohepatic Cycle
- Active drug or metabolite can be excreted in the feces
- Drugs can be secreted and subsequently reabsorbed
- Metabolites can be secreted and then reconverted to the active drug in the intestinal lumen by bacterial enzymes and reabsorbed (e.g. oral contraceptives)
Renal Clearance
Cl = (U x V) / P
Intrinsic ability of the liver to eliminate a drug in the absence of limitations imposed by blood flow.
Intrinsic Clearance
Orally administered drugs must pass through the liver before gaining access to the systemic circulation.
First Pass Effect
Cl = 0
Drug filtered and completely reabsorbed
Cl = ~120 ml/min
Drug filtered and not reabsorbed
Cl = ~650 ml/min
Drug filtered and maximally secreted