Module 1 Study Guide PDF

Study Guide: Module 1 Unit A Full Prescriptive Authority The right to prescribe medications without limitation. Prescriptive Authority Determination Determined by the laws in the state of practice. Food and Drug Administration (FDA) A federal agency responsible for regulating medic...

Study Guide: Module 1 Unit A Full Prescriptive Authority The right to prescribe medications without limitation. Prescriptive Authority Determination Determined by the laws in the state of practice. Food and Drug Administration (FDA) A federal agency responsible for regulating medications and medical devices. FDA's Role Ensures the safety, efficacy, and security of drugs, biological products, and medical devices. Monitors the safety of these products. FDA Drug Approval Criteria Safety: The drug must be safe for its intended use. Efficacy: The drug must be effective for its intended use. Drug Enforcement Administration (DEA) A federal agency that enforces the controlled substances laws and regulations of the United States. DEA Number Requirement Required for prescribing controlled/scheduled drugs. Every prescription must include a valid DEA number. FDA Phases of Human Drug Studies Phase 1: Purpose: Evaluate safety. Subjects: 40-50 healthy volunteers. Phase 2: Purpose: Evaluate efficacy. Subjects: 10-100 patients with the target disease/disorder. Phase 3: Purpose: Test safety and efficacy. Subjects: Several hundred to several thousand patients, controlled and uncontrolled trials. Randomized and blind. Phase 4: Purpose: Post-market surveillance. Subjects: Varies, continued monitoring. Drug Classifications Over-the-Counter (OTC) Medications: Sold directly to the consumer without a prescription.  Used for self-diagnosed conditions and do not require medical supervision. Prescription (Noncontrolled) Medications: Sold only with a valid prescription from a healthcare provider. Controlled (Scheduled) Medications: Classified into 5 schedules based on medical use and abuse potential. Schedule I: Highest abuse potential (e.g., Heroin, LSD). Schedule V: Lowest abuse potential. Why Some Drugs are Controlled/Scheduled Due to their high potential for abuse and potential for severe psychological or physical dependence. Refills Allowed for Scheduled Drugs Schedule I: No refills, no accepted medical use. Schedule II: No refills, new prescription required. Schedule III & IV: Refillable up to 5 times within 6 months. Schedule V: Refills as authorized by the prescriber. Elements of a Bona Fide Patient-Provider Relationship Complete medical history. Physical examination. Documentation of findings and treatment plan. Off-Label Prescribing  Legal if it benefits the patient and is based on scientific evidence. Not illegal, contraindicated, or investigational. Quality of Evidence Pyramid Systematic Reviews and Meta-Analyses: Highest level, comprehensive synthesis of multiple studies. Randomized Controlled Trials (RCTs): Gold standard for testing efficacy, second highest level. Cohort Studies: Follow groups over time, establish sequence of events. Case-Control Studies: Compare those with a condition to those without, identify risk factors. Cross-Sectional Studies: Analyze data at one point in time, identify associations. Case Series and Case Reports: Detailed observations, low level of evidence. Expert Opinion and Editorials: Based on clinical experience, least reliable. Unit B Rational Drug Selection Define the patient’s problem: Clearly identify the medical issue. Specify the therapeutic objective: Determine if the goal is curative, symptom relief, or management. Choose the treatment: Consider allergies, drug/drug interactions, cost, and availability. Educate the patient: Provide necessary information about the medication and its use. Monitor effectiveness: Follow up to ensure the treatment is working as intended. WHO’s 6 steps for Rational Prescribing 1. Identify the patient’s problem. 2. Specify the therapeutic objective. 3. Choose the appropriate drug. 4. Start the treatment. 5. Provide information, instructions, and warnings. 6. Monitor the treatment and adjust as needed. Shared decsion-making and prescribing Shared decision-making involves the patient's preferences, which predict therapeutic alliance and treatment adherence, leading to better outcomes. Eight standard Questions for Safe & Effective Prescribing  1. What pathology should be altered? (Goal of therapy) 2. What drug categories are available to treat the pathology, and how are they different? (Related drug classes) 3. How do the different drugs address the pathology? (Mechanism of action) 4. What are the distinguishing features of specific drugs in the class? 5. How does the drug get into the body and how well is it absorbed? (Pharmacokinetics) 6. How is the drug distributed and metabolized in the body? (Pharmacokinetics) 7. How does the drug leave the body? Are there issues with clearance or excretion? (Pharmacokinetics) 8. What is the safety profile of the chosen drug? (Side effects, drug interactions, pregnancy, breastfeeding, patient education) Patient History & Prescribing Patient history helps avoid polypharmacy and drug interactions. Remember the AVOID acronym: A - Allergies V - Vitamins and herbs O - Old or OTC medications I - Interactions D - Dependency (need for a contract) M - Mendel (family history of drug reactions or benefits) What is medication reconciliation, and how does it improve patient care? Medication reconciliation is creating an accurate list of all medications a patient takes, including name, dosage, frequency, and route. It ensures patient safety by avoiding errors at every patient encounter. Reconciling medications must occur for every patient and at every patient encounter. Required Elements of a Prescription Patient's name, date of birth, and address. Inscription: Drug name and concentration. Form of the drug (tablet, capsule, liquid). Strength of the medication. Sigma (SIG): Instructions for use. Dispense: Quantity of medication. Number of refills. Prescriber’s signature, DEA number (if applicable), and state license number or NPI. Office address and telephone number. E-prescribing, paper prescribing, and verbal prescribing safety E-prescribing: Most popular, reduces errors from poor handwriting, integrates with electronic medical records.  Paper prescribing: Less common, requires tamper-resistant pads, clear handwriting is crucial. Verbal prescribing: Used for urgent needs, requires the receiver to repeat back the order to avoid errors. Maximizing safety: Clear communication, using standard formats, and verification by repeating orders back in verbal prescribing. Bioavailability, Chemical Equivalence, & Brand vs. Generic Drugs Bioavailability: The rate and extent to which a drug is absorbed and available at the site of action. Chemical equivalence: Two drug preparations with the same amount of identical chemical compounds. Importance in prescribing: Knowing bioavailability differences between brand and generic drugs is essential. State laws often allow generic substitution unless bioavailability issues are known. Unit C Pharmacokinetics Definition: The movement of a drug through the body, including four main processes: absorption, distribution, metabolism, and excretion. Absorption Absorption and distribution determine the route of medication administration. Lipid Solubility: Highly lipid-soluble drugs are absorbed more rapidly than drugs with low lipid solubility because they can readily cross membranes separating them from the blood. Blood-brain Barrier: Unique anatomy of CNS capillaries with tight junctions prevents drug passage. Only lipid-soluble drugs or those with a transport system can pass. PGP pumps drugs back into the blood and away from the brain. Not fully developed at birth. Placental Drug Transfer: Placental membranes do not constitute an absolute barrier; most drugs cross via simple diffusion. Protein Binding: Drugs can form reversible bonds with proteins, mainly plasma albumin. Protein binding restricts drug distribution and can lead to high free concentrations and toxicity. Protein-bound drugs are inactive. Oral Medications: Need to be absorbed through the GI tract, impacted by factors like pH levels.  Enteric-coated Medications: Designed to dissolve in a higher pH after leaving the stomach. Routes of Administration: Different routes (oral, rectal, sublingual, etc.) are chosen based on absorption and distribution needs. Metabolism Hepatic Drug Metabolizing Enzymes: Most liver metabolism is performed by the hepatic microsomal enzyme system (P450). Prodrug: A compound pharmacologically inactive as administered but metabolized to an active form. Active drug is available immediately and does not need tobe metabolized first. Special Consideration in Age: Infants have limited drug-metabolizing capacity, and the liver does not fully develop until 1 year old. CYP Induction: Increases the rate of hepatic metabolism, decreasing serum concentrations of other drugs metabolized by the same enzyme. CYP Inhibition: Decreases the rate of hepatic metabolism, increasing serum concentrations of other drugs metabolized by the same enzyme. Substrate: The substance on which an enzyme acts. First Pass Effect: Rapid hepatic deactivation of certain oral drugs before they reach systemic circulation, altering the drug dose.  Genetic Variations: Genetic differences can affect drug metabolism rates (poor, intermediate, extensive, ultra-rapid metabolizers). Excretion Renal Drug Excretion: Kidneys are the primary site for drug excretion, limiting drug duration in healthy individuals and increasing duration and intensity in those with impaired renal function. Glomerular Filtration: Moves drugs from blood to urine; drugs bound to albumin do not pass. Passive Tubular Reabsorption: Reabsorption of lipid-soluble drugs back into the blood. Active Tubular Secretion: Active transport of drugs into urine. Nonrenal Excretion: Includes excretion through breast milk, bile, lungs, sweat, and saliva, but has minimal clinical significance. Time Course of Drug Responses Plasma Drug Level: Amount of drug in the blood correlates with therapeutic and toxic responses. Minimum Concentration: The lowest plasma drug level at which therapeutic effects occur. Toxic Concentration: The plasma level at which toxic effects begin. Therapeutic Range: The plasma drug level range between the minimum concentration and toxic concentration.  Drug Half-life: The time required for the amount of drug in the body to decrease by 50%; dosing is based on half-life. Area Under the Curve (AUC): A measure of total systemic exposure to the drug, representing the total drug exposure over time. Dose-Response Maximal Efficacy: The largest effect a drug can produce, indicated by the height of the dose-response curve. Relative Potency: The amount of drug needed to elicit an effect, indicated by the position of the dose-response curve along the x-axis. Drug-Receptor Interactions Affinity: The strength of attraction between a drug and its receptor. Activation: The drug's ability to cause the receptor to activate after binding. Agonist: Drugs that bind to the receptor and mimic the action of endogenous molecules. Antagonist: Drugs that block the action of endogenous molecules, preventing activation; no effect if no agonist is present. Partial Agonist: Drugs that bind to the receptor and have only a moderate expression of the endogenous molecule's action. Therapeutic Index  Definition: A measure of a drug's safety. A wide/large/high therapeutic index indicates a relatively safe drug; a small/low/narrow therapeutic index indicates a relatively unsafe drug. Unit D Terminology in Prescribing Side Effects Definition: Nearly unavoidable secondary drug effect produced at therapeutic doses. Examples: Headache, nausea, vomiting, diarrhea. Characteristics: Generally predictable and dose-dependent. Note: Side effects can be either good or bad. For instance, ibuprofen can reduce menstrual flow as a side effect when used for menstrual cramps. Adverse Effects Definition: Noxious, unintended, undesired effects occurring at normal drug dosages. Range: From mild (nausea, headache) to severe (anaphylactic reaction). Serious Adverse Effects: Include outcomes such as death, life-threatening events, hospitalization, significant incapacity, or congenital anomalies. Precautions  Definition: Identifies adverse reactions and other clinically significant reactions that have implications for prescribing and management. Importance: Helps in considering risk, benefits, and alternatives. Black Box Warning Definition: FDA's most stringent warning for drugs and medical devices. Purpose: Alerts to serious side effects such as injury or death. Examples: Cardiovascular risks with NSAIDs, risks of combining benzodiazepines with opioids. Relative Contraindications Definition: Risk of not using the medication may outweigh the risk of using it. Example: Tetracycline in children, where the risk of spots on teeth may be outweighed by the need to treat a serious infection. Absolute Contraindications Definition: Do not prescribe as it could cause severe or life-threatening conditions. Example: Prescribing penicillin to a patient with a known type 1 penicillin allergy. Drug Interactions Receptor Sites Agonist: Activates receptor to produce a response.  Antagonist: Blocks receptor to prevent a response. Partial Agonist: Produces a partial response. CYP Induction and Inhibition Substrate: Chemical being metabolized by cytochrome enzymes. Inhibitor: Substance that decreases enzyme activity, slowing metabolism of substrates. Inducer: Substance that increases enzyme activity, speeding up metabolism of substrates. Gastric pH and Drug Absorption Antacids increase stomach pH, potentially causing enteric-coated medications to break down prematurely. Some drugs require absorption further down the GI tract, which can be affected by altered pH. Allergic Reactions Type 1 (Immediate Hypersensitivity) Cause: IgE mediated. Symptoms: Anaphylaxis, angioedema, bronchospasm. Timing: Immediately to a few hours after re-exposure. Treatment: Epinephrine, bronchodilators, H1 blockers, glucocorticoids. Note: Occurs after re-exposure to the substance. Type 2 (Antibody-Dependent Cytotoxicity)  Cause: IgG or IgM mediated. Symptoms: Hemolysis, thrombocytopenia, neutropenia, interstitial nephritis. Example: Heparin-induced thrombocytopenia. Treatment: Discontinue medication. Type 3 (Immune Complex Hypersensitivity) Cause: Immune complexes. Symptoms: Serum sickness, fever, arthritis, lymphadenopathy. Example: Serum sickness. Treatment: Discontinue medication. Type 4 (Cell-Mediated or Delayed Hypersensitivity) Cause: T cell-mediated. Symptoms: Skin reactions, ranging from rash to Stevens-Johnson Syndrome. Timing: 48-72 hours after exposure. Treatment: Can be severe; may require burn unit care. Pseudo Allergies Cause: Non-IgE mediated mechanisms, likely mast cell degranulation. Symptoms: Range from mild to severe. Common Triggers: NSAIDs, muscle relaxants.  Note: Do not worsen with repeated exposure. Anticholinergic Reaction Mechanism: Antagonizes action of acetylcholine, inhibiting parasympathetic nerve impulses. Responsible for transmitting messages that effect muscle contractions and memory Risk Groups: Elderly (more pronounced side effects), long-term use linked to dementia. QT Prolongation Definition: Longer than normal interval between depolarization and repolarization. Puts patient at risk for arrythmias - torsades or polymorphic v-tach. Non-modifiable Risk Factors: Female (genetic, hormonal, anatomical factors). Modifiable Risk Factors: Hypokalemia, hypomagnesemia, hypocalcemia, renal or hepatic issues, drug interactions (other QT prolonging drugs), CYP3A4 inhibitors (e.g., grapefruit juice). Food-Drug Interactions Grapefruit: Decreases the intestinal metabolism of certain drugs, raising their blood levels & causing peak effect to be more intense.. Leafy Greens: Contain vitamin K, which can counteract warfarin. Prophylactic Use Definition: Action taken to prevent disease.  Examples: Immunizations, medications taken at lower doses to prevent outbreaks. Chelation Definition: Bonding of ions between molecules to metal ions. Examples: Medications binding to metals like iron, magnesium, calcium, aluminum can be deactivated before they work. Space out supplements with metal from such drugs by at least 2 hours. Drug Allergy History Documentation Essential Questions: How old were you when the reaction occurred? Describe the reaction. When did the reaction occur in relation to the medication? How was the drug administered? Were other medications taken at the same time? What happened when the drug was stopped? Have you taken the drug since the reaction? Important Considerations: Distinguish between true allergies and side effects. Document clearly for accurate risk stratification. Use history to determine the type of reaction and appropriate actions. Unit E Metabolizer Differences Ultra-Rapid Metabolizers: Increase drug metabolism requiring higher dosages for effectiveness. Intermediate & Slow Metabolizers: Decrease drug metabolism causing drug accumulation and potential toxicity, necessitating lower dosages. Genetic Variants: Genetic variants can alter enzyme activity affecting drug metabolism. Example: Warfarin and clopidogrel require genotyping to guide dosage due to genetic variations in CYP2C9 and CYP2C19. Drug Interactions vs. Genetic Alterations in Metabolism Drug-to-Drug Interactions: Inducers: Increase metabolism of other drugs. Inhibitors: Decrease metabolism of other drugs. Substrates: Drugs metabolized by the same enzyme, leading to competition. Genetic Alterations: Poor Metabolizers: Slow drug metabolism. Extensive Metabolizers (Normal): Standard drug metabolism. Ultra-Rapid Metabolizers: Fast drug metabolism. Pharmacotherapeutic Considerations by Population Children: Metabolism influenced by developmental stages of kidney and liver. Infants have an undeveloped blood-brain barrier. Elderly: Decreased glomerular filtration, liver mass, and hepatic blood flow. Risk of polypharmacy. Pregnant and Lactating People: Medication safety for fetus/baby. Risk vs. benefit analysis is crucial. Current Evidence: Between 65 to 94% of pregnant people take at least one prescription drug during pregnancy, with 70% taking medication in the first trimester during organogenesis. Sex Differences: Women have a higher risk of adverse drug reactions (75% higher than men). Differences in metabolism and volume of distribution affect drug efficacy and safety. Historical Context: The exclusion of women in clinical trials until 1986 has led to gaps in understanding drug safety and efficacy  for women. Research shows significant biological and physiological differences in drug metabolism between sexes. Drug Classification Systems Letter System (For OTC Medications): A: No risk to fetus. B: No risk in animals or humans. C: Inconclusive data; use if benefits outweigh risks. D: Evidence of fetal risk; use if benefits outweigh risks. X: Contraindicated in pregnancy due to fetal abnormalities. PLLR (For Prescription Drugs): Subsections: Pregnancy (includes labor and delivery). Lactation Female and Males of Reproductive Potential. Purpose: Provides detailed information to assist in shared decision-making and patient counseling. Example Comparison: Tetracycline: Old system (Category D) vs. PLLR (risk summary, clinical considerations, data). Fluconazole (Diflucan): Old system (Category C for single dose, Category D for multiple doses) vs. PLLR (detailed risk summary and data). Key Terms Teratogen: Substance causing malformations by damaging fetal development. Teratogens are characterized by their effect and the time in gestation the exposure occurs. Criteria for drugs to be designated teratogens: 1. Drug must cause characteristic set of malformations 2. Must act only during a specific window of vulnerability (organogenesis - weeks 3-8 in a fetus) 3. Incidence of malformation should increase with increasing dosage and duration of exposure All or Nothing: High doses during preimplantation cause death, while sublethal doses allow recovery. The teratogen will either cause a miscarriage or resorption of the conceptus, or the conceptus will survive without damage. Organogenesis: Formation of organs during embryogenesis weeks 3-8; a critical period for congenital anomalies, highest risk for teratogenic effects. Congenital Malformation: Structural defects present at birth due to genetic or environmental factors. Maternal Conditions and Medication Use Conditions Requiring Medication Despite Risks: Asthma: Controlled asthma is better for both mother and fetus. Seizure Disorder (Phenytoin): Category D, may still be needed during pregnancy.  Hypertension (ACE Inhibitors): Should be replaced with safer alternatives. Listed Teratogens: Accutane (Category X), androgenic agents, ACE inhibitors, statins, warfarin, phenytoin, valproic acid, lithium carbonate, methotrexate, large doses of vitamin A, tetracycline, alcohol, anti-thyroid drugs, DES, statins, misoprostol. BEERs List Identifies drugs likely to cause adverse effects in older adults. Avoid in adults over 65 unless benefits outweigh risks. Significance: Helps reduce inappropriate medication use in the elderly. Polypharmacy Common in geriatric patients. Defined as the use of five or more medications concurrently, including OTC and herbal products. Unit F FDA Approval of Over-the-Counter Medications Requirements: The drug must be considered safe and have a low risk for misuse. Patients must be able to self-diagnose in order to take it.  The drug must be for a condition that can be self-managed. The product can be labeled with adequate instructions for use. Over-the-counter medications are drugs and must have a proven safety track record. The FDA ensures low risk for harm and potential misuse or abuse. Insurance companies may require trials of over-the-counter options before prescribing legend drugs (e.g., for GERD, using antacids, H2 blockers, or PPIs first). Patients use over-the-counter medications due to availability, lower cost, and self-care autonomy. Patient education should include awareness of potential side effects and interactions with prescription medications. Encourage patients to choose products with fewer ingredients to minimize risk. Recommended Daily Allowances (RDA) Definition and Education: RDAs are guidelines for nutrient intake developed for healthy individuals under normal conditions. The percentage of the RDA is usually listed on product labels, essential for assessing the content of vitamin or mineral preparations. Special populations (pregnant women, those with chronic diseases, alcoholics, teenagers, and infants) may have specific and additional needs. RDAs have a known margin of safety; exceeding 150% of the RDA is generally not recommended. Patients should be educated to look at the active ingredients in supplements. Advise patients on the risks of overdosage and the importance of correct dosing. Highlight the potential for interactions between over-the-counter supplements and prescription medications. Fat-Soluble Vitamins Vitamins and Implications: Fat-soluble vitamins include A, D, E, and K. These vitamins can be stored in the liver and fatty tissues, leading to a risk of toxicity with excessive intake. Deficiency of fat-soluble vitamins occurs after prolonged deprivation. Mega-doses can lead to hypervitaminosis more quickly than water-soluble vitamins. Excessive vitamin A intake is teratogenic, causing malformations in fetal development. Contamination of Unregulated Supplements Potential for Contamination: Herbal products and supplements are exempt from FDA standards that require proof of safety and efficacy. There are no standards for potency, efficacy, or purity of marketed herbal medicines. Unregulated supplements may contain unlabeled active pharmaceutical ingredients, leading to potential drug interactions and health risks. Educate patients on the risks associated with unregulated supplements. Highlight the importance of checking for active pharmaceutical ingredients and potential interactions. Active Pharmaceutical Ingredients in Unregulated Supplements Definition and Application: Active pharmaceutical ingredients (APIs) are substances in drugs that are biologically active. Unregulated supplements may contain APIs without proper labeling. Companies might deliberately add active ingredients and omit them from the label, posing risks to consumers. Active drugs in supplements can cause interactions with other medications. Advise patients to be cautious about supplements that may contain hidden APIs. Emphasize the importance of choosing reputable brands and consulting healthcare providers before starting new supplements.