Unit 4 Full Notes, The Fun Version 💊Patho · Pharm · Unit 4 · Full Notes
The Complete AntimicrobialCodex 💊
~ your whole packet, every chapter, now actually fun ~
✅ Built from your packet, every section cross-checked.
0Unit 4 Big Picture 🧭
Unit 4 is about choosing the right medication for the right organism, stopping microbes from multiplying or spreading, and protecting the patient from drug harm.
The one pattern that runs the whole unit. Identify the organism 🔎 → give the drug correctly 💉 → monitor early reactions 👀 → prevent resistance 🛡️ → teach the patient to finish therapy 🏁
🦠 Ch 6 Antibacterial drugs
🧬 Ch 7 Antiviral drugs
🫁 Ch 8 Antitubercular + antifungal
🩹 Ch 5 Alternative routes
🧮 Ch 7 pt 2 Individualized dosing
The harm to watch forAntimicrobials save lives but can cause allergic reactions, kidney injury, liver injury, rhythm problems, severe diarrhea, resistance, and unsafe interactions.
1Antibacterials 🦠
Chapter 6 · the biggest chapter
🧫 Bacteria basics & normal flora
Nurse must knowAntibacterials treat bacterial infections only, never viral. Normal flora are helpful resident bacteria that become a problem only when killed off or moved to the wrong body site. Antibacterials are never casual medications.
Confusion alertSevere watery diarrhea with cramps or fever during or after antibiotics points to C. difficile, not just normal flora loss.
IF "how do I know it's working"→lower fever, improved symptoms, improving white blood cell count
🛡️ Resistance
Resistance means bacteria are no longer killed or suppressed by a drug. It happens in the organism, not the patient.
MDR = a multidrug resistant organism, resistant to 3 or more antibacterial classes.
Causes: overuse, using antibiotics for things they don't treat (like viruses), incorrect use, and stopping early.
🦠 Bacteria change, not patients. Overuse, misuse, or quitting early = resistance.
IF "overuse / incorrect use / stopping early"→think antibiotic resistance
💀 Bactericidal vs ⏸️ Bacteriostatic
💀 Bactericidal kills bacteria. Favored when the immune system is weak, because the drug has to do the killing.
⏸️ Bacteriostatic pauses growth and relies on the immune system to finish. Risky in immunocompromised patients.
⚰️ Cide = kill, static = pause. Weak immune system needs a killer.
IF "immunocompromised + serious infection"→favor a bactericidal drug
🌐 Spectrum & culture
Narrow targets few organisms. Broad hits many but does more flora damage.
Culture grows the organism, sensitivity shows which drugs work → enables targeted therapy.
Damage the wall (think bricks and mortar) so bacteria leak and die. May bind wall proteins, block cross-linking, or overactivate autolysins. Works only on bacteria that HAVE a wall. Common uses include skin and mucous membrane infections, respiratory infections, otitis media, urinary tract infections, wounds, gonorrhea, sepsis, endocarditis, and abscesses.
Block the ribosome so bacteria can't build proteins.
🍃 Folate (metabolism)
sulfonamidestrimethoprim
Block the folic acid pathway bacteria need to make DNA.
🧬 DNA
fluoroquinolones
Block DNA synthesis so bacteria can't reproduce.
🧱🏭🍃🧬 WALL · PROTEIN · FOLATE · DNA. Learn the target, then reason to the toxicity.
🤲 General care + anaphylaxis
BeforeAsk about allergies FIRST (the #1 action). Check the IV site is patent. Infuse many IV antibiotics slowly over about 30 to 60 min.
Anaphylaxis on an IV antibioticStop the infusion ⛔ → keep the access 🔌 → change the tubing → support Airway, Breathing, Circulation.
Exam trapDo NOT finish the dose and do NOT pull the line during anaphylaxis. Stop the drug, keep the access.
🚪 Allergies before antibiotics. 🆎 ABC during a reaction.
🧱 Cell Wall Crew, up close
Penicillins & Cephalosporins
Nurse must knowMore allergic reactions here. A penicillin allergy raises cephalosporin allergy risk (similar structure). Separate oral cephalosporins from iron and antacids, giving the cephalosporin 1 hr before or 4 hr after. Never give procaine penicillin IV — it may look milky white.
Cephalosporin generationsFive generations. Later generations broaden coverage, especially more gram negative. The trap is thinking you only memorize them by number.
🧠 Carbapenems
Nurse must knowCan cause CNS changes including confusion and seizures. Ask about seizure history before giving, and clarify safety if the patient has a seizure history.
💥 Vancomycin (glycopeptide)
Nurse must knowInfuse over at least 60 min, never IV push. Too fast causes hypotension, flushing, red man syndrome, and dysrhythmias. Nephrotoxic + ototoxic, so monitor kidney function and hearing.
🧪 Vancomycin = slow, or you glow. 🔴 Penicillin allergy echoes into cephalosporins. 🧠 Carbapenems can CNS you.
IF "red man syndrome"→vancomycin infused too fast
IF "carbapenem + seizure history"→clarify safety before giving
Mid vancomycin infusion: face and chest flushing, BP drops, no airway swelling. Cause?
👀 reveal answer
An infusion reaction from going too fast. Slow the rate.
🏭 Protein Synthesis Squad, up close
👂🫘 Aminoglycosides
Nurse must knowFor serious systemic infections. Effective but toxic. Signature toxicities = nephrotoxicity + ototoxicity. Baseline BUN, creatinine, and hearing (whisper test) before the first dose. Infuse over 30 to 60 min. After, monitor temp, hearing, intake and output, and kidney labs.
Exam trapBroad or extended spectrum. Bacteriostatic at usual doses, bactericidal at higher doses. Prolong QT. + warfarin = ⬆️ bleeding risk. + digoxin = ⬆️ digoxin toxicity. QT danger is worse with other rhythm drugs. Do not automatically pick "stop warfarin" unless the stem says the prescriber ordered it.
IF "macrolide + warfarin"→increased bleeding, monitor
IF "macrolide + digoxin"→digoxin toxicity risk
🦷 Tetracyclines
Nurse must knowBroad spectrum, usually bacteriostatic. No children under 8, no pregnancy or breastfeeding (permanently stain teeth and enamel). Photosensitivity, so teach sun protection. Dairy, antacids, and iron reduce absorption. Give 1 hr before or 2 hr after meals, with a full glass of water.
🦷 Tetra = teeth, timing, and sun. No milk with tetra.
🧠 Less common: lincosamides, oxazolidinones (linezolid), streptogramins
Nurse must knowReserved for severe infections. Can cause kidney toxicity and vein irritation. Oxazolidinones raise blood pressure and lower blood cell counts — monitor BP and CBC.
Exam trap (high yield!)Linezolid has MAOI activity. Combined with a serotonin drug (an SSRI), it raises the risk of serotonin syndrome. Hold and clarify.
🍃 Folate Blockers, up close
Sulfonamides & Trimethoprim
Nurse must knowThree big risks. 💧 kidney crystals (push fluids unless restricted), 🔥 serious skin reactions including Stevens Johnson syndrome, and 🩸 hemolysis in G6PD deficiency. Trimethoprim raises potassium.
Confusion alertSulfonamide + ACE inhibitor or ARB raises potassium even further. Watch hyperkalemia.
Red flagNew spreading rash + blistering + mouth sores + fever = possible Stevens Johnson. Stop the drug, notify the provider.
Core conceptAntivirals suppress viral replication. They usually do not cure and do not replace the immune system. An immunocompromised patient is at higher risk for severe disease, so adherence matters.
Virus basicsAntivirals are usually virustatic (suppress replication), not virucidal (they do not kill the virus directly), so they lower viral activity until the immune system regains control. A virus is an intracellular parasite that cannot reproduce alone, it hijacks a host cell's machinery. It enters through mucous membranes, the genital or urinary tract, broken skin, or blood products. Viral load is how much virus is present. Virulence is how easily or severely it causes disease (high virulence needs fewer viruses to make you sick).
Retro vs nonretroHIV is the retrovirus, managed with lifelong combination therapy. Nonretroviruses include influenza, hepatitis, herpes, and RSV.
Antiviral anaphylaxisSame as antibiotics. Stop the infusion, keep the access, change the tubing, support ABC. The first IV dose is the highest risk window, so watch closely.
🎯 Antiviral therapy goals
Can shorten the duration of illness, decrease its severity, prevent reactivation of dormant infections, and prevent viral multiplication from reaching disease.
Does NOT guarantee lifelong immunity and does NOT always cure the infection.
Teach: take exactly as prescribed, for the full duration, and space multiple daily doses evenly (q12h, q8h, etc.) to keep blood levels steady.
🦅 First IV dose = hawk eyes. Stop the infusion, keep the access. Finish the course, not just the fever.
🧪 Nonretrovirus examples to know
Hepatitis A, B, CRSV (infants, kids, elders)SARS-CoV-2 (COVID-19)West Nile (encephalitis, meningitis)herpes & influenza
🩺 General IV antiviral safety
Nurse must knowAsk about allergies first. IV antivirals carry higher reaction risk than oral. During the first IV dose, assess every 15 minutes for severe allergic reaction. Inspect the IV site at the start, halfway point, and end. If redness or discomfort, slow the infusion, check for blood return, and follow policy (prevents infiltration, irritation, and phlebitis).
Anaphylaxis signsHives at the site, hypotension, rapid irregular pulse, lip or facial swelling, or a reported lump in the throat (airway tightness). Stop the infusion, keep the access, change the tubing so leftover drug does not keep infusing.
💧 Herpes: acyclovir, valacyclovir, famciclovir
Nurse must knowThey act like counterfeit DNA bases and inhibit viral DNA polymerase. Main risk is kidney injury, worse when dehydrated, because the drug can precipitate (form crystals) in kidney tubules. Teach about 3 liters of fluid per day unless fluid restricted (clarify first if restricted). Give IV acyclovir slowly over at least 60 min. Common side effects are headache, dizziness, nausea, and diarrhea. Can reduce the effectiveness of antiseizure medications, so levels may need closer monitoring. Breastfeeding is not recommended (low birth defect risk but the drug enters breast milk).
Look-alike trapDo not confuse Zovirax (acyclovir, antiVIRal) with Zyvox (linezolid, antiBACterial for MRSA). Match the drug to viral versus bacterial.
💦 AFV = Always Fighting Viruses. Acyclovir = always hydrate. Zovirax for viruses, Zyvox for bacteria.
🤧 Influenza
Nurse must knowStart early, ideally within 48 hours. Three neuraminidase inhibitors: oseltamivir (oral), peramivir (IV), zanamivir (inhaled). Baloxavir is the odd one out, an oral single dose that blocks an influenza enzyme needed for gene transcription.
SafetyZanamivir is inhaled and can cause bronchoconstriction. If a bronchodilator is also used, give the bronchodilator FIRST, then wait 5 to 10 min. Baloxavir, peramivir, and zanamivir can cause acute confusion, delirium, or hallucinations.
Peramivir handlingSingle IV dose. Has no preservative, so dilute carefully, give soon after mixing, and do not mix with other IV medications.
😤 OPZ = neuraminidase. Baloxavir is the odd one out. Zanamivir inhaled → bronchodilator first.
⚠️ Ribavirin
Nurse must knowFor RSV and other severe viral infections, often when others fail. Highly teratogenic and toxic. Can be inhaled (aerosolized). Suppresses red and white blood cells and can become toxic to multiple body systems with prolonged use.
Aerosol safety (big exam point)Pregnant people must NOT administer, handle, enter the room during, or care for the patient during aerosolized ribavirin therapy. A mask does not make exposure safe. Keep pregnant staff and visitors away entirely.
🫁 Hepatitis & liver safety
Hepatitis C. Direct acting antivirals chosen by genotype testing, given as a combination. New combinations can reach a sustained virologic response (the virus stays undetectable or controlled after treatment) with low recurrence. Major interactions, so get a full med list, check baseline liver and hematologic function, and watch for anemia and raised liver enzymes and bilirubin.
Hepatitis B. Long term therapy, at least 48 weeks and possibly lifelong, suppressing viral load rather than fully eliminating it. First line drugs are peginterferon alfa 2a, entecavir, and tenofovir.
Avoid alcohol entirely (no alcohol, not just less) to protect the liver. Report jaundice, dark urine, or light stools.
Peginterferon & entecavirPeginterferon can worsen or unmask depression and is contraindicated in thyroid disease (both hyper- and hypothyroidism). Severe mood changes or self harm thoughts are urgent. Warm the vial by rolling gently, never shake (shaking causes foaming), give subcutaneously, and aspirate after needle insertion because it is harmful if given IV. Entecavir goes on an empty stomach, 2 hr before or after food.
🧪 HCV = combo or no go (genotype picks the combo). HBV = 48 weeks, maybe forever. Peginterferon pokes the mood and thyroid.
🦠 COVID 19 therapies
Remdesivir (IV) acts like counterfeit adenine to suppress viral RNA. Renal toxic, raises liver enzymes, can cause anemia. Do not give with chloroquine or hydroxychloroquine.
Casirivimab + imdevimab are monoclonal antibodies that block binding to ACE2 receptors. Monitor for allergic reactions during and at least 1 hr after, teach that delayed reactions can occur up to 24 hr, and avoid vaccinations for 90 days.
Paxlovid = nirmatrelvir + ritonavir (a protease inhibitor plus a booster). Ritonavir slows drug breakdown and can be liver toxic, so interactions matter.
IF "remdesivir + renal insufficiency"→safety concern
IF "after casirivimab + imdevimab"→avoid vaccinations for 90 days
🧬 HIV & antiretroviral therapy (ART)
Nurse must knowHIV is a retrovirus that attacks CD4 positive T cells (the immune system generals). As CD4 falls, opportunistic infections rise. ART is combination therapy, at least 2 and often 3 drugs, because a single drug breeds resistance. The biggest cause of resistance is missed doses.
TeachingGet a full list of all meds and supplements (interactions are common). Take ART exactly as prescribed. Seek emergency care for swelling of the lips, face, or tongue. Avoid alcohol. Do not take oral ART within 2 hr of an antacid.
Name clues for the drug classes
NRTIs end in -sine / -dineNNRTIs have -vir- in the middlePIs end in -navirINSTIs end in -tegravir
💊 ART = at least 2, usually 3, or you breed resistance. Missing doses = resistant HIV. Sine/dine, vir, navir, tegravir.
TB is slow, sneaky, and stubborn. It spreads airborne through coughing, sneezing, laughing, or singing.
The immune response to a TB test can take 2 to 10 weeks after exposure to show.
A positive skin test often stays positive forever and does NOT by itself prove active, contagious disease.
🫁 TB = slow, sneaky, stubborn. Cough confetti spreads it. 2 to 10 week test lag. Positive forever.
IF "positive test, no symptoms"→latent infection, not automatic contagiousness
🔬 Primary vs secondary & active symptoms
Primary TB starts when the organism reaches the lungs (often upper lobes). A strong immune system walls it off, which can scar and show on x ray.
Secondary TB is reactivation later when immunity weakens (HIV, advanced age, immunosuppressants, smoking). Lesions can liquefy and form cavities that spread infection.
Active TB symptomsPersistent productive cough, weight loss, poor appetite, night sweats, bloody sputum, shortness of breath, fever and chills, chest pain with coughing. Active disease → airborne precautions.
😮💨 Cough + calories + cold sweats = active TB (cough, weight loss, night sweats).
🍓 First line therapy: RIPE
Nurse must knowCombination therapy for at least 6 months, even after feeling better. Transmission risk drops after 2 to 3 weeks of therapy plus improvement, but the patient still finishes the full course. Stopping early causes relapse and resistance.
Works even on dormant TB. Causes peripheral neuropathy, worse with malnutrition, diabetes, alcohol. Linked to B vitamin deficiency, so give vitamin B6.
Suppresses TB reproduction. Bacteriostatic only, so it must be combined. Causes optic neuritis and vision changes that can blind if missed. Baseline vision check.
Shared serious risk🫀 Hepatotoxicity. Avoid alcohol and acetaminophen. Report jaundice, dark urine, light stools. Monitor liver function.
Exam trapEthambutol vision changes = serious, report them. Rifampin orange secretions = expected, reassure. Improving after a few weeks is NOT a reason to stop the meds.
🍓 RIPE: RIF = reds in fluids · INH = I Need Hands (neuropathy) · EMB = Eye-MB (vision) · PZA = uric acid gout.
IF "numbness/tingling on isoniazid"→peripheral neuropathy
IF "big toe / joint pain on pyrazinamide"→think gout
👁️🗨️ DOT, VDOT & drug resistant TB
DOT / VDOTDirectly observed therapy means a health worker watches the patient swallow the dose (video version = VDOT). It reduces relapse and resistance, especially for memory problems, adherence problems, or homelessness. It is supportive help, NOT punishment.
Drug resistant TB (MDR / XDR)Caused mainly by nonadherence or mismanagement, can spread, and untreated is highly likely to be fatal. Combination = bedaquiline, pretomanid, linezolid. High alert, intense monitoring. Avoid grapefruit, do not chew or crush the tablets.
🩺 VECKL = Vision, ECG, CBC, Kidney function, Liver function. The baseline safety checks for drug resistant TB therapy.
IF "bedaquiline or linezolid"→QT prolongation, dysrhythmias
IF "pretomanid or linezolid"→vision / optic nerve monitoring
A patient on RIPE is alarmed by orange tears. Best response?
👀 reveal answer
Reassure that reddish orange secretions from rifampin are expected and harmless.
📈 Expected responses, side effects & nursing care
Therapy is working whenCough and sputum decrease, energy improves, weight gain occurs as appetite returns, and sputum cultures turn negative. Improving is NOT a reason to stop the medications.
Common side effectsAcross RIPE: diarrhea, headache, nausea and vomiting, insomnia. Isoniazid also: breast tenderness or enlargement, loss of appetite, difficulty concentrating, sore throat. Rifampin also: abdominal pain, urinary retention, reddish orange secretions. Pyrazinamide also: muscle aches, acne, sun sensitivity. Pyrazinamide and ethambutol raise uric acid (gout).
Nursing before therapyAssess for liver problems and review baseline liver labs. Ask about all prescription, over-the-counter, and supplement use (interactions are serious). Assess urinary retention risk, check baseline anemia before rifampin, ask about gout before pyrazinamide and ethambutol, and do a baseline vision check before ethambutol.
Nursing during and afterMonitor for jaundice (inspect the sclera near the iris, roof of the mouth, and chest), review liver function tests, check sensation in hands and feet for neuropathy, monitor intake and output and urinary retention, encourage hydration (especially with gout risk), and for diabetics check glucose more often and report sustained elevations.
👩🏫 Patient teaching
Take exactly as prescribed, keep a supply on hand, and continue the full course (usually at least 6 months) even after feeling better or becoming less contagious.
Avoid alcohol and acetaminophen the entire course. Report jaundice, dark urine, or light stools.
Expect rifampin's reddish orange secretions, and know soft contact lenses may stain permanently.
Take pyrazinamide or ethambutol with a full glass of water, and aim for about 3 liters of water daily if not contraindicated.
Report joint pain and swelling, especially the big toe (gout).
Sneaky interactionA patient with high blood pressure on isoniazid should avoid caffeine (coffee, tea, chocolate, colas, stay-awake pills), because isoniazid with caffeine can raise blood pressure dangerously.
Fungi have a thick tough wall and a plasma membrane, and some features resemble human cells, which is why antifungals tend to cause more side effects.
Superficial infections (skin, surface) often treated topically. Nail fungus is hard to treat topically because it hides under the nail.
Deep fungal infections can destroy organs, need systemic therapy, and are especially dangerous in immunocompromised patients.
🍄 Fungi = tough wall + human-like features = side-effect-heavy therapy. Deep infection = systemic.
⚙️ Mechanisms & classes
Nurse must knowMost antifungals disrupt ergosterol, the fungal membrane sterol (the source compares it to human cholesterol). Disrupting it makes the membrane leaky. Echinocandins instead block glucan, part of the fungal wall. Antimetabolites like flucytosine act as counterfeit DNA bases.
🧀 Ergosterol is fungal cholesterol. Glucan is wall mortar (echinocandins). Leaky membrane = fungus can't function.
😱 Amphotericin B (high alert)
Nurse must knowNephrotoxic in essentially all patients. Wastes potassium and magnesium. Long half life of about 15 days, so effects linger. Causes infusion reactions with fever, chills, and rigors. Monitor blood pressure at least hourly during the infusion, plus potassium, magnesium, and kidney function.
PriorityWith a systemic antifungal and a potassium below 3.5, report and act, because low potassium can cause dangerous dysrhythmias. Muscle weakness is often the clue pointing at the low potassium.
More antifungal pearlsAzoles interact with grapefruit, raising drug levels. Echinocandins, watch the calves for clot signs. Vaginal antifungals go in at bedtime, avoid sex during treatment, and finish the full course. General antifungal side effects include taste changes and diarrhea.
📋 Side effects, monitoring & teaching
Side effects vs adverse effectsCommon: taste changes, diarrhea, headache, nausea and vomiting, hair thinning with long term use, injection site pain with IV. Ketoconazole, voriconazole, and griseofulvin raise sun sensitivity. Major adverse effects: anemia, liver toxicity, hypokalemia, Stevens Johnson syndrome, dysrhythmias, and reduced kidney function. A widespread rash with fever or tissue necrosis is an emergency.
Nursing before therapyCheck baseline anemia (red blood cells, hemoglobin), liver enzymes, and kidney function (BUN, creatinine). Review all medications and supplements. Teach azole patients to avoid grapefruit, and teach ketoconazole patients to avoid acid reducers such as antacids and proton pump inhibitors, since low stomach acid blocks its absorption.
Nursing during and afterFirst IV dose, assess every 15 min for reaction. Assess skin every shift for rash and blistering, check for jaundice, and take the apical pulse for 1 full minute at least twice daily. Monitor CBC, BUN, creatinine, and potassium (if potassium is below 3.5, call the prescriber). For terbinafine and flucytosine, watch for infection. For echinocandins, assess the calves for deep vein thrombosis. For amphotericin B, monitor blood pressure at least hourly and watch for shock.
👩🏫 Patient teaching
Report jaundice, dark urine, and light stools. Report pulse irregularities (azole patients may check pulse twice daily if instructed).
Avoid grapefruit on azoles. Use sun protection on ketoconazole, voriconazole, or griseofulvin.
On terbinafine or flucytosine longer than a week, avoid crowds and sick contacts (blood cell suppression risk).
Topical: wash hands after applying, helpers wear gloves, clean and dry skin first. Vaginal antifungals can damage condoms and diaphragms, so plan accordingly.
😬 Amphotericin = "ampho-terrible." Kidneys, potassium, and a loooong tail.
Enteral vs parenteralEnteral routes go through the GI tract (oral, sublingual) and can be slowed by food, absorption, and first pass metabolism. Parenteral routes (IV, IM, subcutaneous, intraosseous) bypass the GI tract, act faster, and carry higher stakes. Wear gloves when a route involves mucous membranes, body fluids, or possible contamination, and never contaminate droppers or applicators.
MindsetRoute details are not small details. The closer a medication gets to the bloodstream, the more careful the nurse must be with the rights of medication administration. Wrong technique can cause medication failure, infection, injury, or serious adverse effects.
🩹 Transdermal patches
Slow steady systemic absorption. Common timings ~24 hr, 3 days (Duragesic), 7 days (Catapres), and some contraceptive patches ~1 month. Remove the old patch before applying a new one (no double dose). Wear gloves, cleanse and dry skin, avoid hairy areas, label with date/time/initials, document the site, do not touch the inside of the patch.
💨 Inhalers & nebulizers
Metered dose inhaler (MDI) = press and inhale together. A breath-activated MDI releases the dose on inhalation and needs less coordination. A spacer with a one-way valve helps when coordination is poor. Nebulizers turn medication into a fine mist (mouthpiece or mask) and suit weak patients, older adults, and small children. Dry powder inhalers need a strong inhale (hard under age 6). After a steroid inhaler, rinse and gargle to prevent thrush.
📝 MDI technique, step by step
Insert the canister, test spray if new or unused, shake well, remove the cap. Breathe out, place and seal lips on the mouthpiece, hold the inhaler upright, inhale while pressing the canister once, hold the breath a few seconds, then exhale slowly. Wait 1 to 2 minutes before a second dose. Cleanse the mouthpiece and replace the cap. With a spacer, start inhaling as soon as the canister is pressed and check the valve opens and closes with each breath.
👁️ Eye drops & ointment
Tilt the head back and have the patient look up and away from the dropper. Pull the lower lid down and place drops in the lower conjunctival sac, never on the cornea. Keep the dropper off the eye and lashes. Press the inner corner (medial nasolacrimal canthus) with tissue to cut systemic absorption, then blink once or twice. Wait 5 min between two different drops. Ointment goes about one fourth inch into the sac, then close the eyes 2 to 3 min, expect temporary blur.
👂 Ear drops
Adult, pull the auricle up and back. Child up to age 3, down and back. Lie on the unaffected side and stay positioned 2 to 5 min to prevent leakage. Keep the dropper off the ear canal.
👃 Nasal sprays & drops
Occlude the other nostril, inhale as you squeeze, keep the head positioned for several minutes for absorption, do not blow the nose until upright. Keep the dropper off the nasal membranes. After a steroid nasal spray, drink fluids to reduce microbial overgrowth. Sinus targeting: side to side while supine reaches the frontal and maxillary sinuses, leaning forward with the head toward the knees reaches the ethmoidal and sphenoidal sinuses.
🗣️ Pharyngeal: spray, mouthwash, lozenges
Local effect only, not for treating infection. Spray with the patient upright, aimed at the back of the throat, nozzle outside the mouth, avoid numbing the tongue. Mouthwash is swished and spit, never swallowed. Lozenges are sucked until dissolved, never chewed.
🧴 Topical lotions, creams, ointments
Cleanse and dry the skin first. Lotion, shake if indicated and rub in. Cream or ointment, apply with a sterile tongue blade or gauze using long smooth strokes. Fingertip unit (FTU) = fingertip to first crease on a gloved finger, about 0.5 gram, used to estimate the right amount.
💊 Rectal suppositories
Useful when vomiting blocks oral meds, or for drugs digestive enzymes would destroy. Position left lateral recumbent. Check the rectum is not full of stool (it wastes the dose). Lubricate with water soluble lube, insert narrow end past the sphincter, about 3 inches (7 to 8 cm) in an adult, stay positioned 5 to 10 min.
🌸 Vaginal medications
Often lithotomy position, at bedtime so it stays in place. Insert the applicator downward first, then upward and backward, about 3 to 4 inches (8 to 10 cm). Lie down 5 to 15 min after, use a light pad, and avoid tampons (they absorb the medication).
🦴 Intraosseous (IO) access
Emergency vascular access through bone (cortex into the medullary space, which connects to the venous system) when IV is hard or impossible, common in trauma, pediatrics, and cardiac arrest. Gives immediate venous access for meds, fluids, blood, and blood draws. Devices may be manual, spring loaded, or drill assisted. Temporary, dwell 24 to 48 hours, then get other access. Watch for extravasation, swelling, or pain (a circulation threat, never ignore it). Fluids may run slowly and need a pressure bag. Removal needs specialty training (empty luer lock syringe on the hub, 90 degree angle, rotate clockwise, pull gently).
🧠 Intraspinal access
Delivers narcotics, anesthetics, or antispasmodics near the spinal cord for pain or severe spasms. Epidural sits between the dura mater and ligamentum flavum (common in labor and surgery, can use EPCA). Intrathecal (spinal) goes into the subarachnoid space with CSF, usually lumbar, as a single dose or continuous. Implantable pumps under the abdominal skin deliver intrathecal medication (such as baclofen or ziconotide) for chronic conditions with fewer side effects. Monitor pain scale, sedation level, and head or neck pain, and clearly label intraspinal devices and tubing, since mixing them with other infusion systems is a serious safety event.
Exam trapsInhaler "not working"? Think technique before drug failure. Patch already on? Remove the old one first. Rectum full of stool? The suppository dose is wasted. Vaginal med? Bedtime, no tampons after.
🩹 Patch check: old off, new on, site logged. 🦴 IO = bone IV for 24 to 48 hr. 💊 Rectal = left side + 3 inches.
The mindsetThe nurse is the final safety checkpoint. Never give a dose that looks unsafe, extreme, unusually high, unusually low, or outside a stated safe range. If it looks off, recalculate, verify units, confirm patient variables, and clarify before giving. Small math errors cause major harm.
⚖️ Weight based dosing (the 3 step recipe)
STEP 1 pounds ÷ 2.2 = kilograms STEP 2 mg/kg/day × kg = total daily dose STEP 3 divide LAST, only if divided doses ordered
Convert to kilograms FIRST. Mixing pounds and kilograms creates a dangerous dose.
Divide the total daily dose, never the patient's weight.
2q12h doses/day
3q8h doses/day
4q6h doses/day
🧮 Kilograms first, then dose. Divide last. q12h = 2, q8h = 3, q6h = 4.
🧢 Maximum dose caps
Nurse must knowCalculate the weight based dose, compare it to the maximum, and give the lower number. Never round above the cap. Clarify if the order exceeds the maximum or looks unsafe.
🧢 Cap slaps. Give the lower number.
📐 Body surface area (BSA)
BSA dose key mg/m² × m² = mg
Measured in square meters, better matches metabolic body size, common for chemotherapy (high risk).
Two methods: a square root formula (calculator friendly but error prone if units are mixed) or a nomogram (a visual height-and-weight chart that can estimate or verify BSA, but only if plotting is accurate).
Keep decimals until the end, round BSA to the nearest hundredth (2 decimals), keep the unit system consistent (do not switch between inches/pounds and centimeters/kilograms midway).
mg/m²/day → find the daily dose first. mg/m²/dose → that IS each dose.
📐 BSA = chemo size. Units or it didn't happen. Decimals live until the end.
🧍 Body weight types
IBW male = 50 kg + 2.3 kg per inch over 5 ft IBW female = 45.5 kg + 2.3 kg per inch over 5 ft Adjusted = IBW + 0.4 × (actual kg − IBW)
Ideal body weight (IBW) for drugs that don't distribute well into fat. Only the base number differs by sex.
Adjusted body weight (ABW) for obese or pregnant patients. Actual weight must be in kilograms, never plug in pounds.
Lean body weight (LBW) = bone, muscle, organs without fat. Age and sex specific, with tricky constants, so label units and recheck.
Default to actual kilograms unless the stem asks for ideal, adjusted, or lean.
🧍 IBW = base + 2.3 per inch. Male 50, female 45.5. ABW = IBW + 0.4 of the extra. Scary constants need slow math.
🚧 Safe dose range
Nurse must knowConvert to kilograms, calculate the low end and the high end, compare the ordered dose, and hold and clarify if it falls outside the range, too high OR too low. Never self adjust the dose.
🚧 Safe range is your fence. Outside it (either way) = hold and clarify.
✏️ Worked example, top to bottom
Order: 30 mg/kg/day, 3 divided doses, max 1,800 mg/day. Child weighs 66 lb.
66 ÷ 2.2 = 30 kg → 30 × 30 = 900 mg/day (under the 1,800 cap, so use it) → 900 ÷ 3 = 300 mg/dose.
Safe range 10 to 15 mg/kg/day, patient 70 kg, ordered 500 mg/day. Give it?
👀 reveal answer
No. Range = 700 to 1,050 mg/day. 500 is below the range, so hold and clarify. Too low is unsafe too.