NURS 5334 PHARM Module 1

What are the the BON rules and regulations for prescriptive authority for the advance practice nurse? - defer depending on the state prescriptive authority= ability to prescribe without oversight from MD texas has limited prescriptive authority Describe the pharmacokinetic processes of absorption, distribution, metabolism and elimination and how differences in these areas affect drug action. - Absorption: movement of drug into the blood Distribution: movement of the drug into interstitial space of tissues into cells Metabolism: enzymatically mediated alteration of drug structure Elimination: excretion + metabolism all of these things work together to determine drug concentration Compare and contrast pharmacokinetics and pharmacodynamics of special populations—pediatrics, older adults and those that are pregnant. - infants and children have organ immaturity where an elderly person has organ degeration Identify medications with a narrow therapeutic index requiring drug level monitoring. - warfarin, lithium, opioids, and immunosuppressive drugs like tacrolimus and sirolimus Discuss the effect of ionization and pH on absorption. - ionization of drugs is pH dependent. when the pH and fluid on one side of the membrane differs from the other side the drug molecule tends to accumulate on the side that factors ionization. Discuss factors affecting drug distribution - competition for protein binding and alteration of pH ex: When 2 drugs bind to the same site on plasma albumin, coadministration of those drugs produces competition for binding. As a result, binding of one or both agents is reduced causing plasma levels of fee drug to rise. Discuss barriers affecting drug distribution—such as placental membrane, blood brain barrier and volume of distribution. - placental membrane: not an absolute barrier to the passage of drugs. Most drugs cross the placenta via simple diffusion Blood brain barrier: its tight! to leave the blood and reach the site of action within the brain the drug has to be able to cross the capillary wall. Only drugs that are lipid soluble or have a transport system can cross the blood brain barrier significantly Discuss the "first-pass effect"—what effect can this have on distribution of a drug? - the first pass effect refers to the rapid hepatic inactivation of certain oral drugs. When the drugs are absorbed from the GI tract, they are carried directly to the liver through the hepatic portal vein before by enter systemic circulation. If the capacity of the liver to metabolize the drug is extremely high, this drug can be completely inactivated on its first pass through the liver Discuss the significance of the Cytochrome P450 system on metabolism of drugs. - most drug metabolism takes place in the liver by the hepatic microsomal enzyme system known as the p450 system three of the cyp 450 families are designated as CYP1, CYP2, and CYP3 which metabolize drugs. The other nine families metabolize endogenous compounds such as steroids and fatty acids Discuss the major hepatotoxic drugs and possible effects on drug metabolism. - Drugs to treat TB like isoniazid and rifampin are both hepatotoxic. Giving them both together increases risk of liver injury. List various routes of drug elimination—review normal renal function including glomerular filtration, passive tubular reabsorption and active tubular secretion; describe the implications on drug clearance and how elimination affects prescribing. - the kidneys are the major organs of drug excretion if kidney function decreases then you need to reduce dose if drug is metabolized by kidneys the kidneys CANNOT excrete lipid soluble drugs renal excretion begins at the glomerulus Discuss terms used to describe drug actions-agonist, partial agonist, antagonist. - Agonist: drugs that activate receptors by mimic the action of the body's own molectules ex: dopamine- drug that mimics action of norepinephrine at the cardiac receptors Antagonist: prevent receptor activation. drugs like these love the receptor but do not cause high intrinsic activity. ex: antihistamines- bind to histamine receptors which block the response to allergies Partial agonist: moderate intrinsic activity.