NUR 530|Pharmacology and Pathophysiology| Exam 1 Study Guide.(latest 2022)

Pharm 530 Exam 1 Study Guide Objectives: Module 1: Intro to Pharmacology and Pathophysiology 1. Discuss the four main processes that make up pharmacokinetics. -absorption: the process by which drug molecules move from their site of administration to the blood -distribution: the movement or transport of the drug from the site of absorption to the site of action ***inhalation is the fastest route for drug delivery ***interactions affect distribution, like- blood flow (perfusion), solubility, tissue storage, drug-protein binding (mainly albumin) -metabolism: process used by the body to chemically change a drug, typically to make it easier to excrete that drug (drugs that are converted to a less active or more active form) -excretion: how the body removes drugs mainly through Renal (kidney) other ways are bile (liver) sweat, saliva, breast milk & lungs ***rate of excretion affects blood concentration of a drug/its duration of action 2. Discuss the advantages/disadvantages of the various techniques of drug administration as they relate to pharmacokinetics. enteral route: PO or NG; most intended for general circulation, taking advantage of absorptive properties/surfaces of oral mucosa/small intestine/stomach considered safest because the skin barrier is not compromised onset time is relatively slow (liquid is faster than tablet) extended release capsules (ER) reduce # of doses disadvantage: First-pass effect (Drugs must first pass through the liver before they reach their target sites, liver may inactivate them) decreased motility slows emptying time Foods and medications effects this route sublingual: enteral routes; not swallowed, kept in mouth. Oral mucosaQuickly absorb systemically pros: not exposed to low pH of the stomach rapid onset of drug action cons: swallowing before it dissolves (GI will inactive it) Buccal route: cheek, less rapid absorption than sublingual. Be Careful not to place under tongue! Pros:Buccal allows for sustained release delivery Little to no irritation; little discomfort avoids first-pass effect! avoids low pH topical route: includes meds applied to skin or mucous membranes (skin most common) Pros: slow absorption rate many drugs applied topically to produce a local effect less adverse effects than PO/parenteral Cons: may cause burning transdermal patches: slow release (lipid-soluble), weekly patch changes, avoid first pass effect ophthalmic: treat conditions of eye/surrounding area otic: conditions of the ear Intranasal/Inhale (mouth & nose): nasal or systemic conditions; rapid absorption through gas exchange (potential for damage to ciliated cells); nasal secretions may inhibit drug absorption. Avoids first-pass/stomach acidity (low pH). Inspiratory effects vaginal: local, rich blood supply allows for systemic distribution, discouraged if infectious agents are present rectal: local or systemic; steady and reliable form of delivery, discouraged if stool is present or there is obstruction Parenteral routes: drug admin other than enteral or topical intradermal/SQ: difference is depth of injection(ID: dermis. SQ: deepest layers of skin) ■ drugs easily absorbed (more blood flow due to water-soluble) ■ must rotate injection sites to lessen tissue damage ■ must have adequate tissue perfusion at the site of injection intramuscular: directly into large muscles; rich blood supply allows for more rapid onset than oral, ID, or subQ. In SOME cases, drug is formulated in oily, viscous base to allow for slow absorption rate ■ since muscles are large, allows for larger amount of drug to be delivered intravenous: directly into bloodstream; immediately distributes through the body ■ used for very rapid onset ■ avoid first-pass ■ Cons: most dangerous (invasive); med CANNOT be retrieved once delivered. Pathogens have direct route to bloodstream; antidotes for drugs given must always be readily available 3. Describe blood flow to tissues; the ability of a drug to exit the vascular system, and the ability of a drug to enter cells, and then discuss the characteristics of drug molecules that can alter these processes. Your description should include protein binding and factors that influence protein binding. The heart, liver, and kidneys receive a great % of the blood supply and they receive the highest exposure of the drug. Leaving the skin, bones and tissue to receive a meager blood flow getting less of the drug concentration. Also at the local level receive a site that is injured will not receive adequate perfusion, thus limiting blood flow and drug concentration. *Many of the drugs bind reversibly to plasma proteins, particularly albumin, to form drug-protein complexes. These complexes are too large to cross capillary membranes thus affecting distribution due to prolonged duration of action. This is because the medication will get displaced from the albumin/protein over a longer period of time. Instead of being free to work, the medication is bound to protein and you have to wait for it to slowly diffuse off or for the attraction to not be so great. As the bond between drug and protein breaks, the drug is only then able to reach its site of action. Since this occurs over a prolonged time, the duration of action will also be prolonged. At the same time metabolism of the drug is still occurring. Nothing is stopping the drug from being broken down and the 4 steps of pharmacokinetics is still continuing. Thus, increasing potential adverse effects. 4. Describe the ultimate “goal” of drug metabolism. Discuss the general processes involved in drug metabolism and identify the major or vital organs in which most drug metabolism occurs. The ultimate “goal” of drug metabolism (biotransformation) is to chemically change the drug molecule to a usable form for the body. The products of drug metabolism cause the drug to become either less active or more active. With PO medications there is a first pass (a drug concentration is altered after the first metabolic pass); drugs are absorbed from the intestines and then transported to the liver