Key Elements of a Prescription✔️✔️1) Prescriber Name
2) License Number
3) Contact Information
4) DEA number of prescriber and supervising physician
5) Patient Name
6) Patient DOB
7) Patient Allergies
8) Name of Medication
9) Indication for Medication
10) Strength of Medication
11) Dosing Frequency
12) Number of tablets/capsules to disepense
13) Number of refills
14) SIG or instructions for the prescription (E.g. "Take one tablet by mouth daily")
3 primary reasons for drug monitoring✔️✔️1) determine therapeutic dosage
2) evaluating medication adequacy: desired effect achieved
3) identifying adverse effects: presence of patient harm
Pharmacokinetics✔️✔️Study of drug movement throughout the body
Includes drug metabolism and excretion
Passage across cell membrane
,Absorption✔️✔️Drug's movement from site of administration to the blood
Rate=how soon effects begin
Amount=how intense the effects will be
Rate of absorption depends on✔️✔️rate of dissolution
surface area
blood flow
lipid solubility
pH partitioning
Distribution✔️✔️Drug's movement from blood into interstitial space and then into cells
Metabolism✔️✔️"Biotransformation"
Enzyme mediated alteration of the drug structure
Excretion✔️✔️How drugs and metabolites move out of the body
Elimination✔️✔️combination of metabolism and excretion
Movement of drugs✔️✔️GI Tract/Site of administration-->Blood-->Liver/Kidney/Site of
action/Other Sites-->Bile/Urine-->Outside of body
3 ways for drugs to cross cell membrane✔️✔️1) Channels and pores
2) Transport systems (P-glycoprotein)
3) Direct penetration of the membrane - **Most common**
, P-Glycoprotein✔️✔️Transmembrane protein that transports a wide variety of drugs out of cells
Liver to Bile; Kidney to Urine, Placenta to Maternal blood; Brain to Blood
Passage of drugs across membrane✔️✔️"Like dissolves like"
cell membrane composition lipid - lipid soluble drugs can cross membrane without help
Must be Non-Ionized to cross from one side to the other
Ions✔️✔️drug will accumulate on side which favors ionization ("pH partitioning or Ion trapping")
pH dependent ionization - acid (proton donor) ionizes in basic/alkaline media; base (proton
accepter) ionizes in acidic media
quarternary ammonium compounds - contain at least one atom of nitrogen and carry a positive
charge
Factors Affecting Drug Absorption✔️✔️Rate of dissolution
Surface Area
Blood Flow
Lipid Solubility
pH Partitioning
Routes of Administration: Intravenous (IV)✔️✔️Advantages: Instaneous absorption, rapid onset
Disadvantages: Expensive, invasive, inconvenient