Pharma 1M Intro PDF

INTRODUCTION TO PHARMACOLOGY Pharmacology – study of the drugs and how the body reacts to it ◾ Pharmacokinetics – movement of drugs inside the body; what the body does to the drug ⇨ 4 Pharmacokinetic Process 1. ABSORPTION ▹ “ how will it get in? ” ▹ movement of t...

INTRODUCTION TO PHARMACOLOGY Pharmacology – study of the drugs and how the body reacts to it ◾ Pharmacokinetics – movement of drugs inside the body; what the body does to the drug ⇨ 4 Pharmacokinetic Process 1. ABSORPTION ▹ “ how will it get in? ” ▹ movement of the drug into the bloodstream after administration ▹ takes place in the duodenum of the small intestine ▹ disintegration (drug is broken down into small particles in an acidic environment like the stomach) and dissolution (small particles combined with liquid) only happens in oral medication ▹ excipients mixed with the drugs to enhance drug dissolution, an example would be simple syrup, vegetable gums, aromatic powder, honey, and various elixirs ABSORPTION METHOD ✓ Passive Transport - does not require energy to move drugs across the membrane ∙ Diffusion – high concentration to low concentration (no help) ∙ Facilitated diffusion – relies on a carrier protein to move the drug to high concentration to low concentration ✓ Active Transport - requires a carrier, such as an enzyme or protein, to move a drug against a concentration gradient. Energy is required for this process ✓ Pinocytosis - cells carry a drug across their membranes by engulfing the drug inside a vesicle MUST KNOWS 1. Drug to liquid form are more rapidly available for GI absorption than in solid form because they don’t undergo disintegration 2. Drugs are disintegrated and absorbed faster in acidic fluid with a pH of 1 or 2 rather than alkaline fluids 3. Infants (very young) and older adults have less gastric acidity thus drug absorption is generally slower for there drugs are absorbed primarily in the stomach (give IM or IV instead) 4. Food in the GI tract may interfere with gastric mucosa, so fluids or food may be necessary to dilute the drug concentration and provide protection 5. Blood flow, pain, stress, hunger, food, fasting, and pH affect drug absorption 6. Drugs given rectally are absorbed slower than drugs administered in the oral route 7. Parenteral routes: IM, IV, SUBQ, and ID ** Following absorption of oral drugs from the GI tract they pass from the intestinal lumen to the liver via portal vein ** ▹ First Pass Effect - drug → portal vein → liver (has enzymes that inactivates the drug) → ↓ biovailability ▹ bioavailability refers to the percentage of administered drug availability for activity (oral is always less than 100%) 2. DISTRIBUTION ▹ “ where will it go? “ ▹ movement of the drug from the circulation to the body tissues ▹ increased drug distribution = highly perfused organs (heart, kidneys, liver) ▹ decreased drug distribution = slightly perfused organs (muscles, fat, peripheral organs) FACTORS AFFECTING DISTRIBUTION ✓ vascular and cellular permeability ✓ regional blood flow and pH ✓ cardiac output ✓ tissue perfusion ✓ binding ability of the drug – proteins act like magnets; drugs bind to the protein and gets inactivated thus excreted (i.e albumin, lipoproteins) (check albumin levels first) ⇨ highly protein bound drug ⇨ weakly protein bound drug 3. METABOLISM ▹ “ how is it broken down? “ ▹ biotransformation ▹ body chemically changes a drug into a form that can be excreted ▹ liver is the primary site of metabolism ▹ drug rate is decreased, excess drug accumulation may lead to toxicity ▹ prodrug are compounds that are metabolized into an active pharmacologic substance. These drugs turn into an active form once they enter the body inactive → liver → active ▹ P450 system is an enzyme in the liver that turns lipid soluble into water soluble that can be excreted ▹ half-life is the time it takes for the amount of drug in the body to be reduced by half. The amount of drug administered, the amount of drug remaining in the body from the previous dose ▹ steady state refers to when the amount of drug being administered is the same amount of drug being eliminated (rate in = rate out). It takes about 4 days to achieve steady state ▹ loading dose refers to the administration of large initial dose that is significantly higher than the maintenance dosing to ensure quick therapeutic response. Usually given in emergency cases (given once, first dose) 4. EXCRETION ▹ “ how does it leave? “ ▹ main route of excretion is through the kidneys ▹ also excreted through bile, lungs, saliva, sweat, and breast milk ▹ urine pH influences drug excretion ⇨ alkaline urine excretes weak acid drug ⇨ acidic urine excretes weak base drug ▹ prerenal (before it reaches the kidney i,e. Dehydration and hemorrhage), intrarenal (within the kidney i.e, chronic kidney disease), and postrenal (after the kidneys i.e, Kidney stone) conditions affect drug excretion ▹ BUN and Creatinine are common tests to determine renal function ◾ Pharmacodynamics ◦ what the drug does to the body ◦ involves receptor binding, postreceptor affects, chemical reactions ◦ biologic or physiologic response results from the pharmacodynamic phase ◦ drugs act within the body to mimic the actions of the body’s own chemical messenger Drug Response ◦ Primary effect – desirable response (reason why you are taking the drug) ◦ Secondary effect – desirable or undesirable effect (depending how your body reacts to the drug) Dose - Response Relationship – the body’s physiologic response to changes in drug concentration at the site of action (how the body responds to the given medication) Potency ◦ amount of drug needed to elicit a specific physiologic response to a drug  ◦ expression of the activity of a drug in terms of the concentration or amount of the drug required to produce a desired effect Maximal Efficacy – the point at which increasing drugs’ dosage no longer increases the desired therapeutic level ◦ Efficacy - maximal response to a drug can produce ◦ Potency - measure of dose required to produce a response Therapeutic Index – describes the relationship between the therapeutic dose (ED50) of a drug and the toxic dose (TD50) of a drug Onset – time it takes the drug to reach the minimum effective concentration Peak – occurs when it reaches its highest concentration in the blood ( more drug in the body = strong effect) ◦ peak drug level - highest plasma concentration of a drug at a specific time and indicates the rate of absorption (measures rate at which drug is eliminated) ◦ trough drug level - lowest plasma concentration of a drug and measures the rate at which the drug is eliminated Duration – length of time the drug exerts a therapeutic effect Agonist – drugs that activated receptors and produce a desired response Partial Agonist – drugs that elicite only moderate activity when binding to receptors Antagonist – drugs that prevent receptor activation and block a response Side Effects Adverse Effects Can be both therapeutic and harmful Generally harmful and undesirable Generally do not hinder the main effect Can hinder the treatment and lead to of the drug more complications Mild and self-resolving compared to More severe and life threatening adverse effects Drug toxicity – occurs when drug levels exceed the therapeutic range Tolerance – refers to the decreased responsiveness to a drug over the course of therapy, an individual with drug tolerance will require a higher dosage to achieve the same therapeutic response Tachyphylaxis ◦ an acute, rapid decrease in response to a drug, may occur after the first dose after several doses (acute tolerance) ◦ rapidly diminishing response to successive doses of a drug, rendering less effective Placebo Effect ◦ psychological in origin, the response can be physiologic ◦ person’s physical/mental health appears to impose after taking a place or “dummy” treatment  MECHANISM OF DRUG ACTION a. Drugs that enhances intrinsic activity – stimulation b. Drugs that decreases neural activity and body function – depression c. Drugs that produces noxious effects – irritation d. Drugs that actually replace a particular hormone – replacement e. Drugs that selectively kill invading parasites/cancers – cytotoxic f. Drugs that prevent, inhibit, or kill infectious organisms – antimicrobial g. Drugs that modify, enhance, or depress the immune system – modification of immune status PHARMACODYNAMIC INTERACTIONS ✓ Additives - when two drugs are administered in combination, and response is increased beyond what either can produce. Sum of the effects of the two drugs ✓ Synergistic - the clinical effect of two drugs given together is substantially greater than that of either drug alone ✓ Antagonistic - when two drugs are administered together, one drug reduces or blocks the effect of the other Pregnancy Category Old classification → Traditional FDA drug classes CATEGORY EXPLANATION A Controlled studies shows no risk to fetus B No evidence of risk in humans C Risk cannot be ruled out D Positive evidence of risk X Contraindicated in pregnancy Latest Classification Over-the-counter (OTC) drugs ◦ nonprescription drugs ◦ nursing responsibility is to ensure the client understands and reads OTC labels which includes: product’s active ingredient and purpose of the drug  DRUGS FORMS AND ROUTES FOR DRUG ADMINISTRATION ☐ Solid Forms → tablet - composed of compressed powder; must be swallowed → meltlet - same as the tablet but melts in your mouth → softgel/gel cap - made up of gelatin, easier to take in → capsule - outer covering is made up of gelatin but the inside is powder → caplet - smooth counted tablets that are shaped like capsules → effervescent tablet - dissolves in water ☐ Liquid Preparation → syrup - thick, concentration aqueous preparation of sugar/sugar substitute with or without flavouring agents → elixir - less sweet than syrups and less viscous and with alcohol → suspension - heterogeneous mixture containing solid particles that are sufficiently large for sedimentation → emulsion - mixture of 2 or more liquids that are normally immiscible ☐ Others → transdermal - drug stored in the patch and applied on the skin and is absorbed through the skin (goes through the blood vessel) → topical - applied to the skin by painting or spreading the medication over an area (near the surface) → instillations - liquid medication usually administered as drops, ointments, or sprays → inhalation - metered dose inhalers → suppositories ▹ rectal - cone or spindle shape ▹ vaginal - globular or egg shape → parenteral ▹ intramuscular (IM) - 90 degree angle ▹ subcutaneous (SUBQ) - 45 degree angle ▹ intravenous (IV) - 25 degree angle ▹ intradermal (ID) - 10 to 15 degree angle → others methods: nasogastric tubes, orogastric tubes, and nasoduodenal tubes FIVE + FIVE RIGHTS IN MEDICATION ADMINISTRATION 1. Right patient 2. Right drug 3. Right dose 4. Right route 5. Right time 6. Right assessment 7. Right to refuse 8. Right teaching 9. Right evaluation 10. Right documentation NURSE’S RIGHTS IN ADMINISTERING MEDICATION 1. Right to a complete and clear order 2. Right to have the correct drug route (form) and dose dispense 3. Right to have access and information 4. Right to have policies to guide safe medication administration 5. Right to administer medications safely to identify problems in the system 6. Right to stop, think, and be vigilant when administering medications  Medication Reconciliation ◦ important component of culture safety ◦ was developed to provide drug continuity during care transitions, thereby, promoting patient safety ◦ process of identidying the most accurate list of all medications that the patient is taking at transition in care, includes admission and discharge from a hospital to another healthcare setting The Joint Commision National Patient Safety Goals ◦ do not use abbreviations ◦ only use list of acceptable abbreviations Black Box Warning by US FDA – serves as a warning to be careful because it can be fatal Sharps Safety – Needlestick Safety and Prevention Act (NSPA) Counterfeit Drugs ◦ has no active ingredient, wrong active ingredient, wrong amount of active ingredient ◦ purchase only from licensed pharmacies to prevent exposure to counterfeit drugs High Alert Medications ◦ medication that bears a heightened risk of causing significant patient harm when these medications are used in error ◦ major affections in cardiovascular, respiratory, and neurological systems Medical Plants – bawang, sambong, tsaang gubat, ampalaya, yerba buena, ulasimang bato, bayabas, alkapulko, lagundi, niyog-niyogan Republic Act 9711 (FOOD AND DRUG ADMINISTRATION ACT OF 2009) – BFAD → FDA ; aims to protect and promote the right to health of all Filipino People Republic Act of 9502 (UNIVERSALLY ACCESSIBLE CHEAPER & QUALITY MEDICINES ACT OF 2007) – promote and ensure access to affordable quality drugs & medicines for all Republic Act 6675 (GENERIC ACT OF 1988) – identified by their generic name