Week 1 Review of the Ps Etc. PDF

Review of the ‘P’s. OTC, Herbals, and Vitamins NUR 2403 – Week 1 Housekeeping Registration Review of syllabus and expectations Kaplan Importance of learning generic names for NCLEX Questions Pharmacological Principles Pharmaceutics Pharmacokinetics Pharmacodynamics Pharmacogenomics Pharma...

Review of the ‘P’s. OTC, Herbals, and Vitamins NUR 2403 – Week 1 Housekeeping Registration Review of syllabus and expectations Kaplan Importance of learning generic names for NCLEX Questions Pharmacological Principles Pharmaceutics Pharmacokinetics Pharmacodynamics Pharmacogenomics Pharmacotherapeutics 3 Pharmaceutics Study of how various drug forms influence the way in which the drug affects the body Dissolution Dissolving of solid dosage forms and their absorption SR SA CR XL XT Thin-film 4 Phases of Drug Activity Pharmacokinetics The study of what the body does to the drug From the time drug is put into the body until the parent drug and metabolites have left the body Absorption Distribution Metabolism Excretion 6 Absorption Bioavailability Bioequivalent Parenteral route: First-pass effect Intradermally Subcutaneously Enteral route Intravenously (IV) 100% Sublingual and buccal routes Intramuscularly Topical route Intrathecally Transdermal route Intra-articularly Inhalation route Intra-arterially 7 Enteral Route The drug is absorbed into the systemic circulation through the mucosa of the stomach, or intestine Oral Nasogastric, g-tube, j-tube Sublingual Buccal Rectal *can also be topical 8 Distribution Transport of a drug by the bloodstream to the drug’s site of action Drugs distributed first to areas with extensive blood supply Heart, liver, kidneys and brain 9  Distribution 10 Distribution: Protein Binding Albumin is the most common blood protein and carries most protein- bound drug molecules. If a given drug binds to albumin, only a limited amount of the drug is not bound. This unbound portion is active and is considered “free” drug. Certain conditions lead to low albumin, increasing the chance of toxicity. (burns) Drug interactions can happen if drugs fight to bind. Blood-brain, blood-placenta barriers 11 Distribution: Protein Binding 12 Metabolism Also referred to as biotransformation Biochemical alteration of a drug into any of the following: an inactive metabolite a more soluble compound a more potent metabolite (as in the conversion of an inactive prodrug to its active form) a less active metabolite 13 Hepatic Metabolism Cytochrome P-450 enzymes AKA microsomal enzymes Lipophilic (“fat loving”) Hydrophilic (“water loving”) Substrates – drug molecules that are targets for enzyme Enzyme inhibitors (meds delay metabolism) e.g. erythromycin Enzyme inducers (speed up metabolism) e.g. phenytoin 14 Excretion Elimination of drugs from the body Primary organ responsible is kidney (GF) Liver and bowel also play a role Renal excretion Biliary excretion 15 Other Pharmacokinetics Terms Half-life: time required for half (50%) of a given drug to be removed from the body Steady state Onset of action Peak effect Duration of action 16 Pharmacokinetics Onset of action: time required till therapeutic response Peak level: highest blood level of a drug Trough level: lowest blood level of a drug Toxicity: occurs if the peak blood level of the drug is too high Therapeutic drug monitoring The length of time until the onset and peak of action and the duration of action play an important part in determining the peak level (highest blood level) and trough level (lowest blood level) of a drug. If the peak blood level is too high, then drug toxicity may occur. 17  Pharmacokinetics 18 Pharmacodynamics The study of what the drug does to the body The mechanism of drug actions in cells and tissues Therapeutic effect The goal of drug therapy Mechanism of action {MOA} Receptor interactions Enzyme interactions Nonselective (chemo) 19 Pharmacotherapeutics The clinical use of drugs to prevent and treat diseases Desired therapeutic outcomes is patient-specific, established in collaboration with the patient Outcome goals need to be realistic 20 Pharmacotherapeutics Contraindications Types of Therapy Acute Maintenance Supplemental (or replacement) Palliative Supportive Prophylactic Empirical 21 Pharmacotherapeutics Monitoring Therapeutic action Beneficial effects Adverse drug event Adverse drug reaction Toxic effects Therapeutic index (low = small gap between therapeutic and toxic) Drug concentration Patient condition 22 Pharmacotherapeutics Tolerance: decreasing response to repeated drug doses Dependence: physiological or psychological need for a drug Physical dependence: physiological need for a drug to avoid physical withdrawal symptoms Psychological dependence (addiction): obsessive desire for a drug 23 Pharmacotherapeutics Drug interactions Additive effects (1+1=2) Synergistic effects (1+1=>2) Antagonistic effects (1+1=