Pharmacokinetics (antibiotics): The study of the movement of drugs throughout the body after administration
The random walk throughout the body
Excretion
Done through the kidney. Ionized forms of the drug do not get reabsorbed so having acidic urine will lead to the drug staying in the blood longer.
Distribution
Distribution is greatly affected by the 3 factors: tendency to ionize, lipophilicity, and affinity for proteins
Ionization: the pH of the tissue will greatly affect whether or not the drug will be active there.
Absorption
Dissolution and disintegration
Pathway of drug after taking it PO (important to know because we should be aware of what organs are going to "see" the drug no matter what and what organs are less likely to come in contact with it)
Gut (must diffuse across the cell membrane of the enterocytes and then enter the capillaries to enter the blood stream)
Types of transport across cell membrane: affected mostly by lipophilicity, affinty for proteins, and ability to ionize (these factors are going to affect the RATE of absoprtion)
Passive diffusion (important!)
Active transport via enzymes called transferases
Some oral antifungal agents are meant to stay in the gut and exert their action there
Liver (via the portal vein and may go back into the GI lumen via the biliary system)
Vena cava
Heart
Lungs
Systemic circulation
