Pharmacology Exam 1 Flashcards

What is the difference between a therapeutic effect vs a therapeutic objective?

Therapeutic Effect: Beneficial effect of a medication (opposite of adverse effects, which are harmful or unintended).

Therapeutic Objective: The ability for medications to protect from disease, help with symptoms, or prevent pregnancy. This is the goal of the therapeutic effect. Providing maximum benefit with minimal harm.

What is a prototype drug?

The first medication of its kind; it’s developed to be a “blank slate” for other medications representative of its mechanisms of action and class that acts as an example drug. This is what newer drugs are compared against as the standard.

What is the difference between a generic name and a brand name?

Generic: A global, standardized medication name. There’s only one generic name for a medication. They’re in all lowercase, indicate the drug class in the suffix or prefix, and have consistent active ingredients. Used in clinical practice.

Brand: Names that are produced from pharmaceutical companies. There can be multiple names. These are capitalized and easier for patients to understand. They vary in active ingredients and may not have the same efficacy.

• This is important because incongruence between brand and generic names can lead to medication errors or overdose.

How do brand names contribute to medication errors?

1. Multiple brand names for a single drug. Also easy to confuse the medication.

2. Different active ingredients, even in the same “name” of drug. May cause poor symptom relief to overdose.

3. Brand names differ between countries, which means you could get an entirely different class of medication with the same name.

What are the properties of an “ideal” drug?

1. Effectiveness: The most important. When medications do what they’re supposed to do.

2. Safety: When medications have a reduced capacity to cause harm long-term. Not always avoidable.

3. Selective: The effect that elicits a desired response without widespread effects or side effects. Almost no drug is 100% selective.

   1. No drug is truly ideal due to cost, interactions, patient adherence, and side effects. The goal is therapeutic objective, or causing the most benefit with the least amount of harm.

What are some other properties of ideal drugs?

Reversible Action: Medications wear off or we can give something to stop it.

Predictable: Produce effects you want it to produce in most-to-all patients.

Easy to Administer: Patient adherence and education.

Minimal Interactions: With drugs and other foods.

Cost Effective: Can be easily affordable and accessible.

Chemically Stable: Shelf life.

What is the difference between scheduled, PRN, STAT, and standing orders?

Scheduled Order: Times include before and after. Medications given once a day are given within 2 hours. Medications given more than once daily should be given within 1 hour. If a medication comes more frequently than q4h, provide within 25% of the dosing time (15, 30, 45 minutes). Time critical medications are given within 30 minutes, or immediately.

PRN: Given as needed after a patient meets a predetermined set of circumstances.

STAT: An order that takes priority over other orders. Must be given within 30 minutes.

Standing Order: A pre-approved order that allows medication administration prior to a specific set of circumstances, often in critical situations.

What are the components of a medication order? Give an example.

Medication name, dosage, route, and frequency.

Exp: Potassium Chloride 20mg PO twice daily.

What are all of the routes of medication? What are the pros and cons?

PO - Oral - Asses swallowing ability, GI status, give with water (XR/enteric no crush).

SL - Sublingual - Under tongue/cheek, quick response (5-10min), dissolvable, sip water first.

IM - Intramuscular.

IV - Intravenous - Continuous, piggyback, push. Quick onset that bypasses GI, but technical and vesicants.

SUBQ - Subcutaneous.

Rectal/Vaginal - Suppositories. Need water-based lube.

Inhalant - Rapid or XR. Inhalers, spacers, ET tubes are all examples.

Topical - Ointments, lotions, etc. More localized effects.

Transdermal - Patch, medication goes from skin to bloodstream. Take off old patch, not on hairy areas, don’t touch underside, and write date/time.

Intrathecal - In the spinal canal, not in the nurses’ scope.

How are eye, ear, and nose medications administered?

• Eyes: Lay flat (supine). Pull down lower lid, place drops or ointment, and have patient blink.

• Ears: Lay on side (lateral). Warm solution, tug up and out (for adults), and place drops while patient stays on side for at least a minute. Massage below the ear.

• Nose: Elevate bed (fowlers). Clamp suction of NG tube, flush, place liquid meds and crushed pills, flush again. Do one drug at a time.

What are the various types of drug preparations?

• Solid: Tablet (powder in a disc), capsule (holds drug in container), lozenge (dissolves to release drug), powder (ground), suppository (firm for perineal insertion).

• Liquid: Solution (drugs in water), suspension (larger particles).

• Semi-Solid: Gel (liquifies on skin), paste (thicker than ointment), lotion (emollient), ointment (greasy solution).

• Aerosol (air pressure)

What are the steps you should take if you made a medication error?

1. Assess the patient.

2. Notify provider, preceptor, charge RN.

3. Document in the chart and an incident report.

What are all of the time/frequency abbreviations?

q - Every.

AC - Before Meals.

PC - After Meals.

HS - At Bedtime.

What are the phases of clinical testing?

1. Pre-Clinical Testing: Completed over 1-5 years. Animals are tested to see the harm and benefits of medications.

2. Phase I: Phases 1-3 are completed over 2-10 years. Healthy volunteers are tested to check metabolism, pharmacokinetics, and drug effects of medications.

3. Phases 2 & 3: Patients are tested to analyze therapeutic effects, dosage range, safety, and effectiveness. Note that serious adverse reactions may still not be evident at this stage.

   1. Applications are given to the FDA for approval.

4. Phase 4: General public is surveyed indefinitely to see if any previous points need to be tweaked.

What are three different methods for how to control for confounding factors in clinical trials?

1. Controls: One group is placebo and the other is given the medication; provides scientific baseline for drug effectiveness.

2. Randomized: Equal chance of getting picked for certain groups at the beginning of the study for reducing confounding factors and being more representative of the population.

3. Blinding: Groups are unaware of 9testing boundaries along with the tester in double-blind) to reduce bias and confounding factors.

What are some of the main drug regulations acts?

1. The Pure Food & Drug Act (1906) required clear labelling on products.

2. Later, in 1938, the Food, Drug & Cosmetic Act pushed for approval from the FDA first.

3. The Controlled Substances Act of 1970 established different drugs that can be abused.

4. The FHA Administration Modernization Act (1997) allowed the fast-tracking of drugs.

5. The FDA Amendments Act of 2007 allowed post-market surveillance of medications.

What are limitations of the drug approval process for women and children?

Women: Excluded from clinical trials due to risk of pregnancy, effects on the menstrual cycle.

Children: Excluded from clinical trials due to risk of adverse effects. This is also because of co-surveillance because children cannot advocate for themselves as well.

What is the difference between a leading and trailing zero? Other examples of documentation errors?

• Leading Zero: A lack of a zero in the tens place of a decimal number. “.5” can look like “5,” so you need to write “0.5” instead.

• Trailing Zero: An unnecessary zero in the tenths place of a whole number. “2.0” can look like “20,” so you need to write “2” instead.

• Unspecific Units: Using a non-measurable unit when describing a medication dosage. “cc” should not be replaced with mg/mL, because it doesn’t indicate the amount of medication per volume.

• Uncommon Abbreviations: Any deviations from the standard abbreviations. Using “u” instead of “units,” or "qd” instead of daily.

What are some common medication conversions?

Mass/Linear:

2.2lb = 1 kg.

1 ft = 12 in.

1 in = 2.5 cm.

Liquids:

1 tsp = 5 mL.

3tsp = 1 tbsp = 15mL.

2 tbsp = 1 oz = 30 mL.

0.5 cup = 4 oz = 125 mL.

1 cup = 8 oz = 250 mL.

What are the 6 rights of medication administration?

1. Right Person. Check charts, room numbers, scan wristbands, and verify name and DOB with the patient.

2. Right Medication. Check label and verify medication name. Limit abbreviations.

3. Right Dose. Provide the prescribed dose, and double check with other member of care team. Double-check unit conversions; don’t be afraid of asking questions.

4. Right Route. Provide the prescribed route, and see if it’s appropriate for a patient.

5. Right Time. Check frequency of medication, and make checklists.

6. Right Documentation. Chart within a reasonable timeframe or in the room with the patient, and limit distractions. Provide patient education.

How are medications processed differently between men and women?

• Women have less acidic gastric pH and have slower peristalsis, making absorption slower.

• Women have less enzyme activity in the stomach, so alcohol levels are higher than men even with the same amount of alcohol.

• Men have higher BMI and organs, so they may require larger doses. Women often require smaller doses.

• Women have higher amounts of fat, so lipid-soluble drugs have a longer duration.

• Women have less CYP enzyme activity, causing them to break down medications slower. Women also have lower GFR, lowering excretion.

• Women have a higher overall risk of drug interactions.

How are medications processed differently from members of different ethnic groups?

• Diet and genetics can impact pharmacokinetics and dynamics, which increases risk of adverse effects in certain populations.

• Research has focused on psychotropics and antihypertensive medications, and focuses on both hyper-metabolizers and poor-metabolizers.

• Even members of the same race can have variation in responses to medications.

• Patient adherence and bias can impact how a medication is taken and how often it may be taken.

• Nurses should monitor patients, use inclusive language, and utilize medical interpretation to help with adherence.

How are medications processed differently in older adults?

• Older adults have delayed gastric emptying and pH, causing slower absorption.

• Older adults have higher adipose tissue but less body water, which negatively impacts lipid-soluble medication, and positively impacts water-soluble medication.

• Older adults have less hepatic blood flow and size, which decreases half-life.

• Older adults have less effective renal function, lowering GFR and excretion.

• Improper dosages, multiple medications, poor adherence, comorbidities, high risk medication usage, and improper self-reporting increases med error risk.

• The Beers Criteria is used to note medications that are higher risk in older adult populations, which also includes drug-drug interactions and comorbidities.

• Nurses should provide proper patient education, check to see if patients have access to the medication, and teach the patient methods for better adherence (like pill organizers).

How are medications processed differently in children, infants, and neonates?

• The highest risk for infant adverse drug reactions is organ immaturity. This is why neonates and infants are at the highest risk for drug sensitivity, prolonged drug effects, and longer drug levels.

• KIDs lists are used to note medications that may be inappropriate for pediatric populations.

• Absorption is slower with IM injections, but quicker with transdermal patches.

• Infants have less proteins, leading to less protein-binding with medications, which may result in elevated levels.

• The blood-brain barrier is not fully developed at birth, which increases risk with medications that affect the CNS.

• Infants and neonates have decreased capacity to metabolize medications until they are 1 year old. This is the same for excretion, with renal blood flow, GFR, and tubular secretion being reduced until age 1.

• Children (1-12 yrs) have faster drug metabolism, and have drug sensitivity comparable to adults.

How are medications processed differently in pregnant and/or breastfeeding people?

• Renal blood flow, hepatic metabolism, and GI transit time all increase in pregnancy. This can make drug levels much higher than normal in some cases, and can cause medications to be excreted too quickly in other cases.

• Teratogens are toxic substances that affect the fetus, which can cause malformations, disabilities, or death.

• Even if a medication indicates no level of harm, it’s highly dependent on the pregnant person’s serum levels and physiological state whether or not they will experience an adverse effect.

• The Pregnancy and Lactation Labeling Rule dictates medication safety for the pregnant and/or lactating person, the developing fetus until after birth, and individuals who are of reproductive age.

What is the difference in action between polar ions and nonpolar medications?

Polar: Polar molecules themselves have uneven positive and negative charge, but they have an equal amount of protons and electrons. Ionization is not equal, and either has a positive or negative charge, depending on the gain or loss of electrons.

• These are water-soluble, so they cannot cross the plasma membrane easily. They can utilize channels (high to low concentration) or use facilitated diffusion (low to high concentration).

Nonpolar: Nonpolar molecules are uncharged. They have the opposite effect of polar molecules in their mechanisms for medication administration.

• These are lipid-soluble, so they easily cross the plasma membrane. They often travel through direct penetration (high to low concentration) and facilitated diffusion (low to high concentration).

What do pharmakinetics impact?

Absorption and distribution impact onset of action. They affect how a medication is processed before effects can be utilized.

Metabolism and excretion affect duration of action. They impact the mechanisms of how long a medication will stay in the body.

How do nurses maintain medication safety?

1. Nurses are the final line of defense for patient safety regarding medication administration. It is our job to verify orders for accuracy from prescribers and dispensers. It’s important to ensure this is an informed and focused task.

2. Nurses are responsible for adhering to the 6 rights of medication administration, as well as providing education for the patients regarding symptoms, therapeutic effects, storage, and restrictions.

3. Nurses must check patients prior to and after medication administration, along with health history to note high-risk patients. See if the regimen is appropriate for the patient. And, educate the patient to prevent further errors, and establish the goals of care.

How are medications absorbed?

Absorption happens when medications travel until they reach the bloodstream:

• Dissolution Rate: More dissolution, more absorption. Drugs need to be dissolved before absorption.

• Surface Area: The larger the surface area, the quicker the absorption. This is why they are mostly absorbed in GI (villi, microvilli).

• Blood Flow: The higher the blood flow, the higher the absorption. Increase in concentration gradients, like in GI and skin.

• Lipid Solubility: The higher the lipid solubility, the higher the absorption. They can pass through plasma membranes.

• pH Partitioning: The higher the pH difference the higher ionization rates, the more absorption. The stomach and duodenum have low pH, absorbing acidic medications. The small intestine absorbs more alkaline medications.

• Bioavailability: The amount of medication available for use in the bloodstream after absorption. Oral meds have a bioavailability of around 50%, while IV’s have 100%.

What are the fastest absorption rates versus the slowest, in order?

IV, SL, IM/SUBQ, NG, PO, rectal/vaginal, eyes/ears/nose, topical/transdermal.

What are the different forms of medication absorption?

• IV: No barriers in absorption because of direct bloodstream access. This is rapid, controlled, and allows irritant drug usage. But, costly, inconvenient, and irreversible mistakes.

• IM/SUBQ: Only barrier is the capillary wall. Medications pass through muscle cells easily from big gaps. Can be rapid or slow absorption. Great for poorly soluble medications/depot preparations. Can be an inconvenience.

• SL: Almost quick as IV absorption, and the second-fastest route due to the high vasculature under the tongue. Buccal routes are similar, but administered between the tongue and cheek.

• PO: Barriers are GI cells and capillary wall. Drugs can only pass through cells instead of going around them. Absorption depends on pH, solubility, emptying time, food, other drugs, and drug coatings. They pass through to the portal vein into the liver. They’re easier to do yourself and effects are more reversible, but can cause irritation and variable absorption.

What types of medications prolong absorption?

Enteric-Coated (EC): Medications have coating so they don’t dissolve in the stomach, which helps stomach upset. Do not crush.

Sustained Release (SR, XL): Medication is located in little beads inside the medication, allowing for slower absorption and steady drug levels.

Transdermal Patch: Allows for steady and prolonged absorption over 1-7 days.

How are medications distributed?

Distribution happens when medication moves from the bloodstream into cells:

• Blood Flow: More blood flow, more distribution. Medications go from the blood into the target tissue, so the speed of that is determined by the amount of flow.

• Exiting Vascular System: Easier route of exit, more distribution. Medications need to leave through capillary beds (easier from pores).

• Protein Binding: More protein binding, less distribution. Medications often bind to albumin (made in liver, essential for kidneys) in the bloodstream and don’t detach from their bond until they reach their designated site. If there are multiple protein bound drugs, this increases distribution, while singular protein bound drugs lower it.

• Entering Cells: Non-polar molecules can enter cells far easier than polar ones, increasing distribution. Lipid-soluble, small, and non-polar enter easier than water-soluble, larger, and polar.

What is the difference in distribution between the blood-brain barrier and the placenta?

The blood-brain barrier has tighter capillary walls, so medications can only pass when they can go directly through the wall, making this process more difficult. They also have PGP pumps, which push medications back to the bloodstream. This is similar with the placenta, which has PGP pumps to prevent polar medication from reaching it; otherwise, it’s not a great barrier, because bigger medications can slip through (except heparin and insulin).

How are medications metabolized?

Metabolism happens when medications are altered by enzymes:

• P450 Enzymes: Created in the liver through cytochrome P 450. There are 9 enzyme families that break down fats, and 3 enzyme families that break down medications (by converting drugs to water-soluble forms for excretion) but it can cause drug-drug interactions and food interactions.

  • Induction: Increases enzymes and metabolism, causing less active drugs.

  • Inhibition: Decreases enzymes and metabolism, causing more active drugs.

  • Competition: Drugs compete for activity, causing lower metabolism and increased therapeutic effect for longer (may contribute to toxicity).

Why shouldn’t patients have grapefruit juice?

Grapefruit juice inhibits 2 of the 6 major CYP enzymes for medication metabolism, which causes an increase in drug serum levels, potentially leading to toxicity or overdose of certain medications. It’s best to encourage patients not to consume grapefruit in any form to reduce adverse effect risk.

What is the first pass effect?

When the liver rapidly causes the inactivation of some oral drugs due to their potential to rapidly increase metabolism (because they pass through the portal vein). These medications become inactivated before entering circulation. This is solved through higher initial doses, or through parenteral/SL routes.

What are the consequences of drug metabolism?

• Increased Excretion: Turning lipid-soluble medications into water-soluble medications.

• Drug Inactivation: Converting from active to inactive form, decreasing toxicity.

• Drug Activation (Prodrugs): Prodrugs are inactive as administered and become activated from metabolism.

• Increased Toxicity: Too much of a drug accumulates, leading to overdose.

What are normal AST and ALT levels?

AST: 5-40 units. The enzyme that breaks down amino acids.

ALT: 7-56 units. The enzyme that turns protein into energy.

• If each are high, it indicates liver impairment. Patients with liver impairment should avoid hepatotoxic medications to reduce damage. Liver impairment results in less P450 enzymes, leading to higher drug levels over time.

How are medications excreted?

Medications are excreted through bile, urine, sweat, air, and other avenues. The most important organ for excretion is the kidney:

• Filtration: Filtration starts at the glomerulus, which have small pores. If GFR is low, there is less excretion, leading to higher drug levels. Does not filter drugs bound to albumin.

• Passive Reabsorption: Vessels deliver blood from the glomerulus into the distal tubule, which has lower concentrations of drugs. This gradient moves drugs from the nephron back into the blood if they are lipid-soluble (can cross walls easy).

• Active Secretion: Transport systems in the kidney move water-soluble drugs from the blood to urine directly, one for acids and another for bases.

• pH Ionization: Increases drug excretion, making previously lipid-soluble medications water-soluble.

  • This can be manipulated through ionization of the urine itself, with acidic medications ionizing in more basic urine, and vice-versa.

• Competition for Transport: Decreases drug excretion, because pumps can only hold so many molecules, making the process slower.

What are normal BUN and Creatinine levels?

BUN: 10-20 units. Helps to assess kidney and hydration status.

Creatinine: 0.6-1.3 units. Helps to assess GFR. Anything over 4 indicates serious impairment.

• If each are high, it indicates kidney impairment. Patients with kidney impairment should avoid nephrotoxic medications to reduce damage. Kidney impairment results in lower GFR, leading to higher drug levels over time due to decreased excretion.

What is the difference between affinity, efficacy, potency, and selectivity?

• Affinity: The higher the affinity, the higher a drug is attracted to its receptor. These are more portent by increasing effects at lower doses.

• Efficacy: The higher the efficacy, the higher the intrinsic activity (how much a drug activates after binding), the higher the drug activity and response to the medication, producing an intended response. This is the largest effect a drug can produce (bigger isn’t always better).

• Potency: The more potent the medication, the lower the dose is needed to provide an effect, This is the amount of drug needed to give an effect.

• Selectivity: The more selective, the more medications can bind to a receptor; the more a receptor interacts with bodily processes, the more likely there is for unintended effects, making them less selective.

What are the goals of pharmacodynamics?

The measure of how a medication effects are given over time with a specific dose. The goal is to achieve the therapeutic objective (maximum response) with the lowest dose and least amount of side effects.

How does receptor theory relate to pharmacodynamics?

Receptors are proteins the allow drugs to bind to it, which is reversible. Our bodies have our own molecules that bind to receptors (endogenous) or we use drugs to mimic that mechanism (exogenous). Receptors relate to affinity, efficacy, and selectivity.

What is the difference between an agonist and an antagonist?

Agonist: Molecules (not just medications) that activate receptors. Drugs do this when they mimic receptors’ effects. They represent affinity and efficacy.

Antagonist: Block the activation of receptors, preventing anything to bind from them and trigger responses. They represent affinity without efficacy (because there is no effect).

What are some non-receptor effects?

• Neutralizing Chemicals: Direct chemical reactions neutralize effects, like antacids (pH change).

• Anticoagulants: Neutralizing electrical charges in plasma proteins to prevent clotting, like warfarin.

• Promoting Osmosis: Promoting the movement of fluid to produce an effect, like laxatives.

What is the difference between peak and trough?

The level of medication in the blood to indicate the dosage, and therefore interpret the effects. These are representative of steady state. Peak levels are 1-2 hours after the medication is given, and trough levels are done before the next dose. This can be modified through IV infusion or through modifications of dosage and frequency of administration.

What factors make up the therapeutic range?

• Therapeutic Index: The wider the index, the larger the gap is between the MEC and the toxic concentration. If a therapeutic index is narrow, they are high alert medications, which require regular monitoring and a dual sign-off. Monitor patients for signs of toxicity, and report to a provider.

• Minimum Effective Concentration: The lowest level of a drug that can produce a therapeutic response.

• Toxic Concentration: The threshold above the therapeutic range that increases negative effects (overdose).

• Half-Life: The longer the half life, the less frequently Half-life is the time it takes for half of a drug to leave the body, which indicates how often a medication should be given to maintain therapeutic range.

What are the 4 main types of therapeutic treatments?

• Acute: Short-term conditions.

• Maintenance: Chronic conditions.

• Palliative: Relieve symptoms; no cure.

• Prophylactic: Prevents problems.

What is the difference between a side effect, an adverse effect, and an allergic reaction?

• Side Effect: An unavoidable, secondary effect at therapeutic levels of a medication. This can be beneficial or harmful.

• Adverse Effect: An undesired, unpredictable effect from normal dosages of a medication. Effects can be minor or delayed.

• Allergic Reaction: A negative immune-response dependent on the degree of sensitization to a drug. Can range from mild symptoms to anaphylaxis, regardless of dose.

What are some types of adverse effects?

1. Idiosyncratic: An uncommon, adverse drug reaction that stems from genetic predispositions.

2. Tolerance: When a medication becomes less effective over time, requiring higher doses.

3. Physical Dependence: A state where the body has adapted to a drug wherein absence will lead to abstinence syndrome, which can cause withdrawal symptoms and has a potential for harm.

4. Resistance: Pathogens will develop resistance to medications, making them ineffective over time.

5. Antidote: An antagonist to a drug’s effects, reversing residual effects.

6. Carcinogenic: The ability for medications or environmental chemicals to cause cancer.

7. Hepato/Nephrotoxic: Medications that damage the liver or kidneys. Compounds are converted into toxic products that can injure the individual cells, which can result in liver or kidney failure. This effect is increased with concurrent alcohol consumption.

8. Vesicant: An IV drug that destroys local tissues.

What can nurses do to reduce the risk of allergic reactions in patients?

1. Review medications multiple times, as well as looking at armband and MAR.

2. Check in on patient after medication administration.

3. Look for active ingredients, and make note of cross-sensitivity (like people with latex allergies also being allergic to bananas).

What is a black box warning?

The strongest safety warning a medication can carry and still remain on the market. These are FDA labels that are on medications with the possibility of producing serious or life-threatening effects.

How should nurses address the possibilities of adverse effects from medications?

1. Patient education.

2. Careful monitoring of vulnerable populations.

3. Anticipate more common reactions.

What are drug interactions?

When another substance interacts with a medication’s efficacy, effects, and/or safety.

What are the consequences of drug-drug interactions?

1. Potentiate Effects: Can cause beneficial, therapeutic effects, or unbeneficial interactions that cause adverse effects.

2. Inhibitory Interactions: Can cause beneficial interactions that decrease adverse ones, or can cause unbeneficial interactions that decrease therapeutic ones.

3. Unintended Effects: Unique interactions that are completely unique from the medications’ base effects.

What increases the risk of drug interactions?

1. Certain medications can interact with one another which can inactivate both medications.

   1. Precipitate: When solids form in liquid medications, like IV solution. These should be discontinued.

2. Two medications can be toxic to the same organ, increasing interactions (hepatotoxic and nephrotoxic).

How do drug-drug interactions effect pharmacokinetics?

• Absorption: Can change gastric pH, affecting absorption. Can also change peristalsis, which affects blood flow.

• Distribution: pH partitioning and increased extracellular pH increases ionization of acidic drugs, drawing them out of cells. Can also cause more competition for protein binding.

• Metabolism: Changes CYP enzymes by inactivating them, decreasing metabolism (induction, inhibition, competition).

• Excretion: GFR can decrease, lowering the amount of medication that passes through filtration. Can also alter urinary pH, which affects pH ionization (passive reabsorption). And, can affect competition for active transport.

How do drug-drug interactions effect pharmacodynamics?

Interactions at the same receptor are purely inhibitory and happen when antagonist drugs block agonist drugs in a receptor (decrease therapeutic effects or toxicity). And, if different receptors are responsible for controlling the same system, then interactions will influence the same physiological response (inhibitory, prohibitive).

How do food-drug interactions effect pharmacokinetics?

• Decreased Absorption: Food can decrease absorption (rate, onset of action) and extent, which can result in a lack of therapeutic effect.

• Increased Absorption: Peak effects are increased, causing them to be more intense.

• Decreased Metabolism: CYP enzymes are inhibited, which increase serum levels of medications (causing toxicity or therapeutic effects).

How can nurses prevent drug interactions?

• Nurses should… Provide medication reconciliation. Overlook each medication (+OTC), see how often they’re taken, what dosage they are, and if there are any discontinued medications.

• Nurses should… educate patients on interactions through side-effects and various resources. Check for early signs of toxicity.

• Nurses should… Pay attention to meal timing surrounding medication administration. If food reduces absorption, give on an empty stomach. If it increases it, give it surrounding meals.

• Nurses should… Warn patients about grapefruit juice, and their ability to cause toxicity and overdose from the inactivation of liver enzymes.

What is the difference between behind the counter and over the counter medications? What are the consequences?

• Behind the Counter: Medications that are received with a prescription, through insurance, from a pharmacist. These require patient education prior to administration. Can treat minor to major conditions, and are far more regulated.

  • These medications are far more likely to be abused.

• Over the Counter: Medications that are purchased without a prescription, with or without the discretion from a doctor, and may not include patient education unless requested. Often treats minor conditions, and less regulated depending on states.

  • Ask doctor before taking the medication, follow package instructions.

What is the difference between vitamins and supplements?

• Vitamins: Micronutrients that are used by the body for metabolism. These are organic compounds that help with growth and health. They do not create energy. Can be fat-soluble or water-soluble.

  • Vitamins and supplements are not regulated under the FDA.

• Supplements: Intended for ingestion and contain dietary ingredients for further nutritional value (vitamins, minerals, enzymes, fiber, etc.)

  • Most people that take these are already healthy, and evidence is mixed.

What is the difference between recommended dietary allowance and upper intake level?

• Recommended Dietary Allowance: The average daily intake for healthy individuals to maintain nutrition. These are variable and not fixed.

• Upper Intake Level: The highest nutritional intake from everyone that they can take without the risk of adverse effects.

What are some vitamins that cause negative symptoms?

• Vitamin A: Increases the risk of toxicity in pregnant women; acts as a teratogen.

• Vitamin E: Increases platelet aggregation (clotting) which increases hemorrhage risk.

• Vitamin C: Increases GI irritation (nausea, cramps, diarrhea).