Pharm Final Review PDF

# Final Review ## Know the variety of reasons meds are prescribed - **Prevention:** Some meds are used to prevent diseases or conditions from developing. - Ex. Vaccines are given to prevent infectious diseases. - **Diagnosis:** Some meds, like contrast dye, can help healthcare providers diagn...

# Final Review ## Know the variety of reasons meds are prescribed - **Prevention:** Some meds are used to prevent diseases or conditions from developing. - Ex. Vaccines are given to prevent infectious diseases. - **Diagnosis:** Some meds, like contrast dye, can help healthcare providers diagnose specific conditions. - **Symptom Treatment or Management:** Relieves symptoms without necessarily curing underlying conditions. - Ex. Analgesics like aspirin are used to treat pain. - **Curative:** Curative meds aim to eliminate the cause of the disease. - Ex. Antibiotics kill bacteria causing infections. - **Health Maintenance:** Meds taken regularly to maintain health. - Ex. Meds to control blood pressure, like metoprolol, which is used for hypertension. - **Contraception:** Meds to prevent reproduction, i.e. pregnancy, like birth control pills. ## Know the rights of medication administration **Note:** Not all meds fit neatly into one category, and some meds can have multiple uses. - **10 Rights of Med Admin:** Ensure safe med practices and uphold patient rights, which are: - **Right Med:** Verify the med matches the prescriber’s note, order, and the patient's needs. - **Right Dose:** Ensure the dose is accurate and appropriate for age, weight, and condition. - **Right Patient:** Confirm the patient's identity using identifiers (e.g., name, birthdate) before administering meds. - **Right Route:** Administer med via route prescribed (e.g. oral, IV, IM). - **Right Time & Frequency:** Give the med at the scheduled time and frequency, adhering to the prescriber’s instructions. - **Right Documentation:** Record the med admin accurately + accurately in the patient’s med record. - **Right Reason** Understand rationale for the med and its intended therapeutic effect. - **Right to Refuse:** Respect the patient's right to decline med, explaining potential consequences. - **Right Education:** Inform the patient about med name, purpose, potential side effects, administration instructions, and med assessment. - **Right Evaluation:** Monitor the patient’s response to meds, assessing therapeutic effects and adverse effects. ## Know how meds are legislated - What allows meds to be sold? The primary legislation governing meds in Canada are the *Food & Drugs Act* and the *Controlled Drugs & Substances Act (CDSA)*. - **Food & Drugs Act:** - Came into effect in 1876 and mandates that all meds approved for use in Canada must meet prescribed standards. - Requires standards for: - Production - Testing - Manufacturing - Usage - Marketing - The act recognizes specific formularies, which are lists of meds approved for use. (Meds listed in formularies are considered safe and effective for their intended use.) - The Act establishes various schedules for meds to categorize meds based on their risk and potential for misuse. - **Controlled Substances and Drug Act:** - Enacted in 1997 and replaced by the *Narcotic Control Act*. - Sets stricter regulations for controlled substances. - Dictates requirements for drug classification, specifying the levels of control for different meds based on potential for addiction and misuse. ## What allows meds to be sold? - **Compliance with Legislation:** Drugs can be sold in Canada only if they meet the standards outlined in the *Food & Drugs Act* and *CDSA*. This means they've been rigorously tested, manufactured according to regulations, and deemed safe and effective for intended use. - **Marketing Authorization:** Health Canada grants marketing authorization to meds that have successfully completed the regulatory process. - **Proper Dispensing:** Medications must be dispensed by licensed healthcare professionals (pharmacists) in accordance with regulations. ## Know the difference between prescribed and OTC meds? - **Prescription and OTC Meds differ in:** accessibility, regulations, associated risks. - **Prescription Meds:** - Require a valid prescription from a licensed healthcare professional (e.g., physician, NP). - Prescription meds are typically stronger and have a higher risk of side effects or interactions, necessitating professional oversight. - Dispensed by licensed pharmacists to ensure proper dispensing, accurate dosage, and appropriate labeling. - Subject to stricter regulatory oversight, Health Canada evaluates these meds rigorously for safety and efficacy before granting marketing authorization. - Patient-specific instructions and prescriptions contain detailed info about dosage, frequency, route of admin, and any special instructions tailored to the patient's need. - **OTC Medications:** - Available without a prescription. Consumers can purchase OTC meds directly from pharmacies or other retail outlets. - This accessibility reflects that these types of meds are generally low risk. - Regulated by Health Canada, but less stringent requirements than prescription drugs. - Standardized labeling. OTC meds feature a “Drug Facts” table on their packaging, which provides information on purposes, use, storage, dosage, warnings, and potential adverse reactions. - This informs the customer about safe and appropriate med use. - Potentially risky if misused: OTC meds can pose risks and if misused, taken in excessive doses, or combined with meds without consulting a healthcare professional. ## Know the different naming formats and types of classifications - **Chemical name:** Describes the chemical structure of the drug. - **Generic Name:** Describes the drug’s pharmacological or chemical characteristics. - There is only one per drug. - Not capitalized, and may be written in smaller letters. - **Trade name:** Is the name of the company who manufactures and sells the drug. - Trade names are capitalized and written after the generic. - Ex. Generic name for Valium is diazepam, so it’s written: Diazepam (Valium) ## Know how drugs are classified - **Therapeutic Class:** A broad category based on drugs’ therapeutic effect. - Examples include: analgesics and sedatives. - They include several pharmacological classes. - For example, the therapeutic class "antihypertensives" has at least 13 pharmacological classes. - **Pharmacological Class:** Drugs grouped by therapeutic class work in different ways, are not chemically similar, and have different mechanisms of action. - Only include other drugs that have the same mechanisms of action. - Ex. Angiotensin-converting enzyme inhibitors (ACE): Work by inhibiting the enzyme that converts angiotensin I to angiotensin II. - They describe a drug's property in a specific way and are necessary when determining treatment. - Generic drugs within the same pharmacological class typically have the same suffix. - Ex. ACE inhibitors end in “pril,” like captopril (Capoten), enalapril (Vasotec), lisinopril (Zestril), and ramipril (Altace). ## Know what needs to be included in a doctor’s note Before a nurse can administer drugs, there must be a written med order from a doctor on a patient’s chart or prescription - **Med orders contain:** - Patient Full Name - Date and Time Order was written - Med Name - Dose (amount or strength of med) - Never use a trailing zero with med orders (e.g., 1.0 mg), but always use a leading zero for decimal dosages (e.g., 0.1 mg). - Route of Admin - Time & Frequency of Admin - Signature of Prescriber - Additional information may include: the pharmaceutical preparation (e.g., solution, suspension, capsule), directions for checking with the doctor, # of refills, labeling instructions, and the physician’s registration #. ## Know which sources are best to locate med info A nurse must find, interpret, and apply drug info to provide safe and effective care. Sources include: - **Pharmacology Textbook:** Such as *Pharmacology for Canadian Health Care Practice* because it provides foundational knowledge about drugs, drug classifications, mechanisms of action, indications, contraindications, adverse effects, and nursing implications. - **Drug Handbooks:** Like *Davis’s Drug Guide* offers comprehensive and concise info about specific meds, usually organized alphabetically by generic name and provide detailed info including dosages, admin routes, adverse effects, and drug interactions. - **Pharmacists:** Can provide valuable info about drug interactions, side effects, and appropriate dosages. They can answer questions about specific meds and help clarify any confusion about a med order. - **Electronic Database:** Such as *E-CPS (Electronic Compendium of Pharmaceuticals and Specialties)*, *Lexicomp*, *Nursing Central* provide up-to-date info about meds, including approved uses, dosages, admin routes, contraindications, precautions, adverse effects, and interactions. ## Know how the nursing process is used, including what tasks are used for each in drug admin 1. **Assessment:** - **Data Collection:** The nurse should gather subjective and objective data about the patient including med history, documenting all meds the pt is using including prescription, OTC, med profile, allergies, and any relevant lab results. - **Ex:** Obtain a thorough med history by documenting all meds used including prescriptions, over-the-counter, and non-prescription (NAP.) - Assess the patient's understanding of their meds and potential side effects. - Review lab results such as liver and kidney function tests to identify and potential contraindications or dosage ex: Nursing diagnosis 2. **Analysis of Data:** The nurse analyzes collected info to formulate nursing diagnoses that identify the patient’s actual or potential problems related to med therapy. - **Ex:** Deficient knowledge related to med regimen as evidenced by pt verbalization of misunderstanding of med instructions. - **Risk for injury related to potential side effects**, such as: drowsiness or dizzy. - **Constipation related to opioids** due to the decrease in bowel movement and straining. 3. **Planning:** Setting goals/outcomes - The nurse develops a plan of care that includes measurable and achievable goals and outcome criteria that are specific to the patient’s needs. - **Ex:** Goal: Patient will not experience any adverse effects from their meds. - **Outcome criteria:** Patient will report any side effects to the nurse immediately. 4. **Implementation (Interventions)**: Carrying out the plan of care - the nurse implements planned interventions, including patient med admin, education, and monitoring for therapeutic and adverse effects. - **Ex:** Administer med according to the 10 Rights of Med admin. - Provide clear and concise patient education on med purpose, dosage, route of admin, schedule, potential side effects, and any special instructions. - Monitor the patient’s response to med therapy, including both desired therapeutic and adverse effects. 5. **Evaluation:** - **Determining Effectiveness:** The nurse evaluates the effectiveness of the interventions by assessing whether the patient has achieved the desired outcome goals. The nurse also identifies any new problems or needs that require modification of the care plan. - Ex. Evaluate patient understanding of their med regimen by asking them to repeat back med therapeutic effect such a pain relief, BP control, or improved motility. - Assess for any adverse effects and document appropriately. - If adverse effects occur, notify the prescriber and implement appropriate interventions. ## Know the variety of routes of admin - How they differ as well as med types - **There are 3 basic routes:** - **Enteral (Via GI tract):** Oral meds are swallowed and absorbed through the stomach or small intestine. - Ex. A doctor may order metoprolol 50 mg PO BID to treat patient’s BP. - **Sublingual:** Meds are placed under the tongue and absorbed through the mucous membranes. DO NOT swallow. - **Buccal:** Meds are placed between the cheek and gums, absorbed through mucous membranes. - **Rectal:** Meds are inserted into the rectum and absorbed through mucous membranes. - They can have local effects, such as lubricating stool, or systemic effects such as relieving nausea or pain. - **Parenteral:** Administration bypasses the GI tract, often involving injections: Injectable forms include solutions, suspensions, emulsions, and powders that are reconstituted before admin. - **Topical:** Meds are applied to skin or mucous membranes. - Different pharmaceutical preparations are used for topical admin such as: - **Ointments:** Semisolid preparations that keep med in contact with the skin for a longer duration. - **Creams:** Semisolid emulsions applied to skin, easily removable by water. - **Pastes:** Thick semisolid preparations for topical application. - **Powders:** Finely ground particles for topical application. - **Solutions:** These can be topical preparations for the skin or mucous membranes ## OD - Overdose - **Foams:** Meds dispensed in a foam form for topical application. - **Gels:** Semisolid systems for topical application, often providing a cooling sensation. - **Transdermal Patches:** Deliver medication through the skin over an extended period of time. Requires removal of old patch to prevent potential OD. - **Inhalers:** Devices that deliver meds to the lungs through inhalation. - **Different formulations affect the rate of absorption:** - Ex. IV admin provides the fastest absorption as meds enter the bloodstream directly; enteric-coated tablets dissolve in the intestine, slowing down absorption and protecting the meds from stomach acid or irritating the stomach is reduced. - **The absorption rate reflects the time it takes for the med to reach the bloodstream.** ## Know the 3 Checks for Med Admin 1. **Before removing the med from the med drawer:** This initial check verifies the **correct med** is selected before any prep begins. 2. **Before opening or pouring the drug:** The 2nd check confirms the **med and dosage form** (also checks the expiry date). 3. **After opening or pouring the drug** - Provide another opportunity to verify the **correct med and dosage** before administering to the patient. ## Know how meds are stored and accessed - **Unit Dose System:** Meds are individually packaged and labeled in the pharmacy and each patient has a designated drawer with their initials. - Pharmacy refills drawers every 24 hours. - This system enhances safety and accuracy by minimizing handling of meds on the clinical unit. - **Traditional System (Stock Supply):** Where meds are stored in bulk, multi-dose containers on the clinical unit. - This system may be convenient, but it can increase the risk of med errors due to nurses needing to measure and prepare individual doses. - **Automated Systems:** Use computerized controls for med dispensing. Nurses access these systems with a code and enter the patient’s ID # to select med dose and route electronically. - These systems can improve accuracy and efficiency but require careful monitoring and maintenance to ensure proper functioning. ## Regardless of system used, narcotics and controlled meds are always securely locked on the clinical unit to prevent unauthorized access. - Nurses with access have keys to the locked areas and careful documentation is required for every dispensed dose. ## Know the types of orders and what they look like on the MAR 1. **Routine Orders:** These are standard orders for meds given on a regular schedule, such as daily or multiple times a day. - On the MAR, they often have specific times or a timeframe for admin. - Ex. “Every 6 hours” or “BID (twice a day)” or “Tetracycline 500 mg PO Q6H” or “Decadron 10 mg PO daily x 5 days. 2. **PRN Orders:** “PRN” stands for “pro re nata” meaning as needed. - These orders allow the nurse to administer meds as needed for patients within specified parameters. - The MAR will typically indicate med, dose, route, and timeframe for which it’s prescribed. - Ex: Morphine sulfate 5 mg SC q3-4H PRN for incision pain 3. **Single (One-time) Orders:** These orders are for med admin only once at a specific time. - The MAR will clearly state the med, dose, route, and designated time for admin. - Ex. “Valium 10 mg PO at 0900.” 4. **Stat Orders:** “STAT” means “immediately” and indicates an urgent need for meds. - On the MAR, stat orders are written with the med, dose, and route, emphasizing immediate admin. - Ex. “Give morphine 5 mg IV STAT.” 5. **Now Orders:** Similar to stat, “Now” orders require promptadmin. However, they may allow for a slightly longer timeframe than stat orders. - These orders are documented on the MAR with med, dose, route, with “NOW” highlighting the need for prompt action. - Ex. “Give Ceftriaxone 1 g IV NOW.” 6. **Standing Orders:** These are pre-written orders for specific situations or conditions, allowing nurses to administer meds without obtaining a new order from the prescriber. - Standing orders are detailed on the MAR, in a particular set ink. - It’s important to refer to the agency’s policy and procedure manual. - Students cannot take verbal or phone orders. - Should never modify a physician’s order without clarification. ## Know when med rec needs to be done and why it’s important - **Med Reconciliation (Med Rec):** Is a process to prevent med errors and ensure patient safety and involves comparing a patient’s current med list with any new med orders or changes made to existing regimens. - This process is crucial at various points during a patient’s healthcare journey. - **Admission:** When a patient enters a hospital or health care facility, obtaining a complete med hx including prescriptions, OTC meds, and non-prescription (NIHP). - This process helps identify potential drug interactions and ensures continuity of care. - **Transfer:** When a patient moves to a different unit or level of care within a facility (e.g. from ICU to general ward) or transfer to another healthcare facility, med rec is crucial. - This step ensures meds are appropriately adjusted for the patient’s changing conditions and prevents omission or duplication from hospital or healthcare facility. - **Discharge:** Before a patient is discharged from a hospital or healthcare facility, it’s essential to reconcile their meds again. - Includes providing a clear, updated med list to the patient and their primary caregiver, facilitating a seamless transition back to their usual care routine. - **The primary goal of med rec is to avoid med discrepancies that could lead to adverse drug events.** - **Med rec is critical for ensuring med safety, preventing adverse drug events, and promoting optimal outcomes.** - **If med rec is not performed, omissions of necessary meds for pre-existing conditions during hospitalization, failure to switch from IV to oral meds during transfer, lack of communication about new prescribed meds during hospitalization to the patient’s primary caregivers/providers, leading to potential discontinuation of essential drugs; accidental continuation of meds that should’ve been stopped; insufficient education about new meds and potential interactions before surgery, increasing the risk of injury/complications; meds w/ existing meds, resulting in unintentional double dosing.** ## Know the types of side effects for meds - **Adverse Drug Event (ADE):** Encompasses any undesirable clinical problems resulting from med use, including med errors and adverse drug reactions. - **Med Errors (MEs):** These are preventable events that may lead to inappropriate med use or patient harm while the med is under the control of healthcare professional, patient, or consumer. - MEs can involve the wrong med, dose, route, or time of administration. - **Adverse Drug Reactions (ADRs)**: These are unintended undesirable responses to a med that occur at a normal dose. ADRS can range from mild to severe and some may be predictable based on meds known side effects. - **Allergic Reactions:** These involve the patient’s immune system recognizing a drug or substance as dangerous, which triggers the release of histamine and other inflammatory substances leading to symptoms such as itching, rash, swelling, and difficulty breathing. Anaphylaxis is a severe allergic reaction characterized by a massive release of histamine, potentially causing life-threatening symptoms like airway constriction, a drop in BP, and edema (swelling). - **Idiosyncratic Reactions:** These are unpredictable and unusual responses to a med, often caused by a genetic difference in how a person metabolizes the drug. These reactions may not be related to the pharmacological action and can be difficult to predict. - **Toxic Effects:** Toxicity refers to harmful effects caused by excessive med levels in the body. - These effects can damage organs and systems and risk of toxicity increases with higher dosages or prolonged med use. - Teratogenic, mutagenic, carcinogenic effects are terms describing the potential of a med to cause specific types of harm: - **Teratogenic Effects:** Harmful to a developing fetus, causing birth defects. - **Mutagenic Effects:** Alterations in DNA, increasing the risk of mutation. - **Carcinogenic Effects:** Cancer-causing potential. ## Know Meds: Digoxin, Dimenhydrinate, Pantoprazole Sodium, Diphenhydramine Hydrochloride - **Digoxin:** - **Classification:** Cardiac glycoside. - **MOA:** Increases the force of myocardial contraction, slows heart rate, and improves CO. - **Indications:** Used to treat heart failure and certain types of irregular heartbeats (atrial fibrillation). - **Important Admin Considerations:** Calculation is important. - **Consideration for older adults:** There is an increased risk of adverse effects in older adults due to age-related changes in drug processing. In older adults, kidney function is lower which can lead to toxicity. - **Side Effects:** Digoxin has a narrow therapeutic index which increases the risk of toxicity. Common side effects include GI disturbances (nausea, vomiting, and diarrhea); CNS effects (fatigue, weakness, and visual disturbances (blurred vision, seeing halos around lights]). *More serious side effects (often signs of toxicity) include cardiac arrhythmias, bradycardia. - **Dimenhydrinate (Dimenhydramine Hydrochloride):** - **Classification:** Antihistamines, Dimenhydrinate is known as Gravol. - **MOA:** Blocks H1 receptors preventing Ach from binding to receptors in vestibular nuclei (Can area in the brain). Involved in balance and motion sickness). - **Indications:** Primarily used for motion sickness and nausea, and vomiting. Dimenhydrinate is also used for productive cough, sedation, rhinitis, and allergy symptoms. - **Side Effects:** Can cause drowsiness, dizziness, confusion, blurred vision, dry mouth, and urinary retention. - **Important Considerations:** It’s important to remember the difference between similar sounding drug names. - **Pantoprazole:** - **Classification:** Proton pump inhibitor (PPI). - **MOA:** Irreversibly binds to the H+/K+ ATPase enzyme, blocking the movement of hydrogen ions from parietal cells into the stomach, resulting in a temporary halting of gastric acid secretions (achlorhydria). - **Indications:** Used to treat various acid-related disorders such as gastroesophageal reflux disease (GERD), erosive esophagitis, peptic & duodenal ulcers, Zollinger-Ellison Syndrome, and stress ulcer prophylaxis, also used in combination with antibiotics for *H. pylori* infections. - **Admin Considerations:** The granules from pantoprazole capsules can be administered via nasogastric tubes and the capsules can be opened and mixed with apple juice, but delayed-release granules should not be crushed or chewed. - **Side Effects:** Common ones include headache, diarrhea, abdominal pain. *More serious, though less common side effects include*: predisposition to *Clostridium difficile* infections (which is important to consider in hospital settings), osteoporosis, and increased risk of fractures (wrist, hip, spine) with long-term use, pneumonia, depletion of magnesium. - **Drug Interaction:** Can increase the risk of bleeding when used with warfarin, with clopidogrel, it can affect platelets. ## Know the difference between local us systemic effects of meds - **Local Effects:** - They occur near the site of admin where the med’s applied or enters the body. - The med primarily acts on the targeted area without significant absorption into the bloodstream. - Examples of meds with local effects include: - Topical skin prep for rashes or infections. - Nasal sprays for congestion. - Vaginal creams or suppositories. - Rectal suppositories for constipation or hemorrhoids. - Inhaled meds for asthma. - Eye drops for eye infections or glaucoma. - Ear drops for ear infections or earwax buildup. - Throat lozenges for a sore throat. - **Systemic Effects:** - Occur when the med is absorbed into the bloodstream and distributed throughout the body. - The med acts on cells and tissues in various parts of the body, not just the site of admin. - Examples of meds with systemic effects include: - Oral meds (like pain relievers, antibiotics, or BP meds). - Injections (IM, subcutaneous, IVs). - Transdermal patches (e.g., nicotine patches, nitroglycerin). - Some rectal suppositories (e.g., antiemetics, analgesics). - Some inhaled meds (e.g. general anesthetics). - Sublingual meds (absorbed under the tongue). ## Know the pathway of meds in the body - The pathway of meds through the body is known as pharmacokinetics which involves how the body absorbs, distributes, metabolizes, and excretes, referred to as ADME. - **Absorption:** Movement of a drug from its admin spot into the bloodstream. - **Factors affecting absorption**: Include route of administration, for example, drugs given IV have 100% bioavailability as it enters the bloodstream immediately. - **Drugs given orally**: Have reduced bioavailability because the first pass through the liver, before reaching systemic circulation, which is called the first pass effect reducing the amount of active drug reaches the bloodstream. - **Distribution:** Process by which a drug is transported from the bloodstream to its -target site of action in various tissues and organs. - **Work of Plasma Proteins:** Many drugs bind to plasma proteins, primarily albumin in the blood. - **Drugs bound to proteins are pharmacologically inactive; only the free, unbound portion of a drug can exert itself and its effects.** - **The degree in which a drug binds to proteins influences its distribution and duration of action.** - **Factors like the drug’s affinity for albumin and the patient’s overall protein levels can affect this binding.** - **Metabolism:** Also known as biotransformation, this process involves the chemical alteration of a drug to make it more easily excreted from the body. - **Primary site is the liver** where metabolism is done and the liver is responsible. - **Enzymes:** The liver contains enzymes (the cytochrome P450 system ) that catalyzes these metabolic reactions. - **Outcomes of metabolism:** Drugs can be converted into active metabolites; drugs can be converted to inactive metabolites with their own pharmacological effects; drugs can be made more water-soluble facilitating their excretion by the kidneys. - **Factors Affecting Metabolism:** Genetic differences in enzyme activity; liver disease; age; interactions with other meds can alter drug metabolism rates, leading to either increased or decreased drug effects. - **Excretion:** Removal of drugs and their metabolites from the body. - The **primary organ is the kidneys** and drugs get excreted through urine. - **Other routes:** Bile (feces), lungs (exhaled air), sweat, breast milk. - **Factors Affecting Excretion:** Kidney function, urine pH, drug interactions can impact excretion rates. - **Half-Life:** The time it takes for 1/2 of the drug to be eliminated from the body. - **Clinical Significance:** The half-life determines dosing frequency and the time it takes for a drug to reach steady-state when the amount of drug entering the body equals the amount being eliminated. Drugs with lower half-lives require less frequent dosing, but it also takes longer to reach steady-state to be completely eliminated from the body. ## Understanding the pharmacokinetic pathway of meds is crucial for nurses to: - Anticipate drug actions and potential side effects. - Determine appropriate dosing schedules. - Recognize factors that may influence drug response in individual patients. - Monitor drug therapy effectively. ## Know agonist and antagonist, etc., for types of meds - **Receptor Interactions:** - Many drugs exert their effects by interacting with receptors, which are reactive sites found on the surface and inside of cells. - A drug with stronger affinity for the receptor will elicit a greater response from the cell. - **Agonist:** A drug that binds to a receptor and activates it, producing a biological response. It mimics the action of naturally occurring substances (e.g. hormone, neurotransmitter) that normally binds to the receptor. - **Partial Agonist:** Binds to a receptor and activates it but produces a weaker response compared to a full agonist. - **Antagonist:** Binds to a receptor and doesn’t activate it. Instead, it blocks the receptor from being activated by other substances, including agonists. Antagonists can be further classified as: - **Competitive Antagonists:** This type of antagonist competes with agonists for the same binding site on the receptor. If the antagonist binds, it prevents the agonist from binding and producing a response. - **Noncompetitive Antagonist:** A noncompetitive antagonist binds to a different site on the receptor than the agonist. Its binding alters the receptor shape, preventing the agonist from binding effectively, even if the agonist binding site is available. ## Examples of drug-receptor interactions: - **Agonists:** Albuterol (Ventolin): This med is beta-adrenergic receptor. It binds to β-2 receptors in the lungs, causing bronchodilation, which relieves asthma symptoms. - **Antagonists:** Beta-blockers (e.g. metoprolol): These block the effects of adrenaline and nonadrenaline on the heart, reducing HR and BP. ## Remember Med Math 1. Orders for *hydromorphone* 6 mg PO. Available forms are 1 mg, 2 mg, 4 mg. What do you give and how many tablets provide the ordered dose? - 1 mg = 1 - 2 mg = 1 - 4 mg = 1 - **You would give 1 mg and 1 mg.** 2. The order is for *Lipitor* 75 mg PO, and the available tablets are 25 mg. How many tablets will you give? - DD = 75 mg - AD = 25 mg - V = 1 tablet - **You would give 3 tablets.** 3. You have *Docusate Sodium Liquid* 100 mg/mL. The order is for 30 mg. How much mL would you give? - DD = 300 mg - AD = 100 mg - V = 10 mL - **You would give 3 mL of the med.** 4. The Dr. orders *gentamycin sulfate* 25 mg PO for your 40-year-old client. The label reads 40 mg/mL. How many mL will you administer? - DD = 25 mg - AD = 40 mg - V = 1 mL - **You would give 0.6 mL to your client.** ## Remember: - Show all your work. - Double check calculations. - Write numerical answers correctly. - Round off answers according to instructions: - Nearest tenth (0.1) for adults.   - Nearest hundredth (0.01) for children. - Write out answers in a sentence. - Use only approved calculators. ## Know mechanisms of action for the various anti-emetics, antacids, laxatives, antihistamines: - **Antiemetics:** Block various pathways in the vomiting process, which involve the vomiting center (VC) and the chemoreceptor trigger zone (CTZ) in the brain. - **Anticholinergics:** - **MOA:** Blocks Ach receptors in vestibular nuclei and reticular formation, areas of the brain involved in balance and motion sickness. - **Ex:** Scopolomine - **Antihistamines:** - **MOA:** Block H1 receptors preventing Ach from binding receptors in the vestibular nuclei. - **Ex:** Diphenhydramine, meclizine. - **Antidopaminergics:** - **MOA:** Block dopamine receptors in the CTZ and may also block Ach. - **Ex:** Prochlorperazine hydrochloride, promethazine hydrochloride. - **Prokinetics:** - **MOA:** Blocks dopamine receptors in the CTZ and/or stimulate Ach receptors in the GI tract, increasing motility. - **Ex:** Metoclopramide hydrochloride. - **Serotonin Blockers:** - **MOA:** Block serotonin receptors in the GI tract, CTZ, and VC. - **Ex:** Granisetron hydrochloride, Ondansetron hydrochloride dihydrate, Palonosetron hydrochloride. - **Tetrahydocannabinoids:** - **MOA:** The precise mechanism is complex and not fully understood, but it’s thought to involve cannabinoid receptors in the brain and GI tract. - **Ex:** Medical Marijuana - **Antacids:** Neutralize stomach acid. - **Aluminum Salts:** - **MOA:** Neutralizes stomach acid, but can cause constipation. Often combined with magnesium to counteract. - **Magnesium Salts:** - **MOA:** Neutralizes stomach acid but can cause diarrhea. Avoid in renal failure. - **Calcium Salts:** - **MOA:** Neutralizes stomach acid, but can cause kidney stones and rebound hyperacidity. - **Sodium Bicarbonate:** - **MOA:** A highly soluble antacid with a quick onset but short duration of action. May cause metabolic alkalosis, and is not ideal for patients with heart failure, HTN, or renal insufficiency due to sodium content. - **All Antacids work to raise gastric pH and reduce pain.** - **Laxatives:** Promote BM. - **Bulk-forming laxatives:** - **MOA:** Absorbs water in the intestine, increasing stool mass and stimulating peristalsis. - **Ex:** Methylcellulose. - **Emollient laxatives (Stool softeners/lubricant laxatives):** - **MOA:** Softens stool and facilitates passage by reducing surface tension. They coat the stool, making it slippery. - **Ex:** Docusate sodium. - **Hyperosmotic laxatives:** - **MOA:** Increases osmotic pressure in the intestinal lumen, drawing water into the intestine and softening stool. - **Ex:** Lactulose. - **Saline laxatives:** - **MOA:** Attract and retain water in the intestinal lumen, increasing stool volume and stimulating peristalsis. - **Ex:** Magnesium sulfate. - **Stimulant laxatives:** - **MOA:** Irritate the intestinal mucosa, increasing peristalsis and promoting BM. - **Ex:** Senna. - **Antihistamines:** Blocking histamines - **Traditional (1st Gen) Antihistamines:** - **MOA:** Block histamine receptors at both peripheral (e.g. BV, GI tract) and central (e.g., brain) H1 receptors, which leads to a broader range of effects, including sedation and anticholinergic effects (dry mouth, blurred vision, etc.) - **Ex:** Brompheniramine, chlorpheniramine, dimenhydrinate, diphenhydramine, and promethazine. - **Non-sedating (2nd Gen):** - **MOA:** Primarily block histamine at peripheral H1 receptors, resulting in fewer CNS side effects and less sedation. - **Ex:** Loratadine, Cetirizine, fexofenadine. ## Know how natural/alternative remedies differ from prescribed meds - **Regulations:** Prescribed meds - are regulated under the *Food & Drug Act* and the *Controlled Drugs and Substances Act* which ensure meds undergo rigorous testing for safety, efficacy, and quality control before they’re available to the public. - **Natural/alternative remedies:** Safety profiles are not as well-established as prescribed meds. - Some NHPs may contain ingredients that can cause allergic, toxic reactions, adverse effects, and a risk of interactions with prescribed meds. - **Efficacy:** - **Prescribed meds:** Undergo clinical trials to demonstrate effectiveness for specific conditions. - **NHPs:** Are based on traditional use or anecdotal evidence rather than rigorous scientific research. More research is needed for efficacy and safety for certain conditions. - **Safety:** - **Prescribed meds:** Risks are generally well-defined through