NLE Fundamentals of Nursing & the Nursing Process — Medication Administration & Dosage CalculationSummary

Pharmacokinetics describes what the body does to a medication through four sequential processes: (1) Absorption—the drug enters the bloodstream through the route of administration (oral drugs absorbed from the GI tract, IV drugs achieve 100% bioavailability immediately); (2) Distribution—the drug travels via the circulatory system to target tissues and organs, with factors like plasma protein binding and lipid solubility affecting distribution; (3) Metabolism—predominantly in the liver through enzymatic processes that transform the drug into active or inactive metabolites; and (4) Excretion—mainly through the kidneys (urine), with some through bile, lungs, or other routes. Understanding pharmacokinetics helps nurses predict drug onset, peak effect timing, and duration of action—crucial for scheduling doses and monitoring therapeutic and adverse effects.

Pharmacodynamics describes what a medication does to the body—its mechanism of action and effects. Drugs interact with specific receptors on cells (agonists stimulate the receptor; antagonists block it), producing therapeutic effects (the desired, beneficial response) and side effects (predictable, usually mild, unintended responses like drowsiness with antihistamines). An adverse effect is a harmful or undesirable response (e.g., hepatotoxicity, nephrotoxicity) that may require dose adjustment or discontinuation. Allergic reactions are immune-mediated responses ranging from mild rash to life-threatening anaphylaxis (airway swelling, hypotension, shock). Drug toxicity occurs when drug levels exceed the therapeutic window, producing serious harm. The therapeutic window is the range of blood concentration between the minimum effective dose and the toxic dose—narrow therapeutic windows (e.g., digoxin, theophylline) require careful monitoring.

Medications may be administered via multiple routes, each with distinct advantages, onset times, and risks: (1) Oral (PO)—safest and most convenient; slower onset (30 min to 2 hours); includes regular tablets/capsules, sublingual (under the tongue for rapid absorption, e.g., nitroglycerin), and buccal (against the cheek). Never crush enteric-coated tablets (designed for intestinal release) or sustained-release forms; (2) Topical/transdermal—applied to skin; patches provide sustained release; rotate sites to prevent skin irritation; (3) Inhalation—rapid lung absorption for bronchodilators via metered-dose inhalers (MDI) or nebulizers; (4) Instillation—eye, ear, nose drops; (5) Rectal/vaginal—suppositories; (6) Parenteral (injection)—bypasses GI absorption for faster, more predictable effects: • Intradermal (ID)—10–15° angle, small volumes (~0.1 mL), forms a wheal; for allergy and tuberculin (Mantoux) testing. • Subcutaneous (SC/SQ)—45–90° angle, volumes ≤1 mL (typically ~0.5 mL); used for insulin, heparin, enoxaparin. Do NOT aspirate (check for blood return) or massage after heparin/LMWH to prevent bruising; rotate sites in the abdomen (avoid 5 cm around umbilicus). • Intramuscular (IM)—90° angle; up to ~3 mL in adults (≤1 mL in deltoid); preferred sites are ventrogluteal (safest for adults—away from major nerves and blood vessels), vastus lateralis (preferred for infants and children), deltoid, and dorsogluteal (avoided due to sciatic nerve risk). Use the Z-track technique for irritating medications (e.g., iron dextran) to seal the track and prevent subcutaneous leakage. • Intravenous (IV)—direct into the vein for immediate onset and 100% bioavailability; highest risk; covered under IV therapy section below.

The ten rights provide a systematic framework to prevent medication errors: (1) Right Patient—verify identity using two identifiers (e.g., name and hospital number or birthdate), NEVER room number alone. Check the patient's armband against the medication label; (2) Right Drug—verify the drug name on the label against the physician's order; watch for look-alike/sound-alike names (e.g., Lasix vs. Losartan); (3) Right Dose—calculate and verify the dose is safe and within therapeutic range; (4) Right Route—confirm the ordered route; do not substitute unless ordered; (5) Right Time/Frequency—give at scheduled times; hold doses if parameters contraindicate (e.g., hold digoxin if apical pulse <60 bpm); (6) Right Documentation—chart immediately AFTER administration, never before; include medication name, dose, route, time, site, patient response, and any adverse reactions; (7) Right Reason/Indication—understand why the patient is receiving the medication; (8) Right Assessment—evaluate relevant baseline parameters before giving (e.g., apical pulse for digoxin, blood pressure for antihypertensives, respiratory rate for opioids); (9) Right Response/Evaluation—monitor the patient after administration for therapeutic effect and adverse effects; (10) Right to Refuse—respect the patient's autonomy; if a patient refuses, do not force; document the refusal and notify the physician. Three Checks of the Label: Read the medication label when (1) removing from storage, (2) preparing/pouring, and (3) at the bedside before administering. If a patient questions a medication ('I've never taken this before'), stop and re-verify before administration.

The fundamental formula for calculating medication doses is: Dose to Give = (Desired Dose / Dose on Hand) × Quantity, often abbreviated as D/H × Q. Desired dose (D) is the dose ordered by the physician. Dose on Hand (H) is the strength of the medication available (e.g., 250 mg per tablet). Quantity (Q) is the volume or number of units in which the dose on hand is supplied. Example 1 (tablets): Order = 500 mg; on hand = 250 mg per tablet. Give = (500/250) × 1 = 2 tablets. Example 2 (liquid): Order = 375 mg; on hand = 250 mg per 5 mL. Give = (375/250) × 5 = 1.5 × 5 = 7.5 mL. Always convert to the same unit before calculating (e.g., if the order is in grams and the stock is in mg, convert grams to mg first). Round the final answer appropriately—tablets are not typically split unless scored, and drops are rounded to the nearest whole number (you cannot give 0.5 of a drop).

Accurate dosage calculations require fluency with metric, household, and apothecary measurements. Memorize these essential conversions: Weight: 1 gram (g) = 1,000 milligrams (mg); 1 mg = 1,000 micrograms (mcg or µg); 1 kilogram (kg) = 1,000 g; 1 kg = 2.2 pounds (lb). Volume: 1 liter (L) = 1,000 milliliters (mL); 1 mL = 1 cubic centimeter (cc) [note: modern practice favors mL over cc]. Household measurements: 1 teaspoon (tsp) = 5 mL; 1 tablespoon (tbsp) = 15 mL; 1 fluid ounce (fl oz) ≈ 30 mL. Example conversion problem: A patient weighs 154 lb and is prescribed a drug at 5 mg/kg. Convert weight: 154 lb ÷ 2.2 = 70 kg. Calculate dose: 5 mg/kg × 70 kg = 350 mg. Always move values to the same unit before applying the D/H × Q formula or weight-based dose calculation.

Many medications, especially in pediatrics and for certain adult drugs (e.g., chemotherapy), are prescribed based on patient body weight to ensure safe, individualized dosing. The formula is: Dose = Ordered dose (mg/kg) × Patient weight (kg). Step 1: Convert patient weight from pounds to kilograms if needed (divide by 2.2). Step 2: Multiply the prescribed dose per kilogram by the patient's weight. Step 3: Verify the calculated dose is within the published safe dose range for that medication and patient age/condition. Example: A 35-lb child is prescribed amoxicillin at 25 mg/kg. Step 1: 35 lb ÷ 2.2 = 15.9 kg (round to 16 kg). Step 2: 25 mg/kg × 16 kg = 400 mg. Step 3: Check that 400 mg is within the safe pediatric range (typically yes for this dose). Always verify before administering because pediatric dosing errors can have serious consequences. Some drugs specify a maximum total dose regardless of weight (e.g., 'do not exceed 500 mg').

IV therapy requires accurate calculation of infusion rates to deliver the prescribed volume over the correct time period. Two formulas are used depending on the infusion device: (1) mL/hour (for electronic infusion pumps): Rate (mL/hr) = Total Volume (mL) / Total Time (hr). Example: Infuse 1,000 mL over 8 hours. Rate = 1,000 mL / 8 hr = 125 mL/hr. Program the pump to 125 mL/hr. (2) Drops per minute (gtt/min) for gravity infusion sets: gtt/min = [Total Volume (mL) × Drop Factor (gtt/mL)] / Total Time (minutes). Drop factor (also called drip rate) varies: macrodrip sets deliver 10, 15, or 20 gtt/mL (listed on the IV set box); microdrip (Buretrol) delivers 60 gtt/mL. Example: Infuse 1,000 mL over 8 hours (480 minutes) with a 15 gtt/mL macrodrip set. gtt/min = (1,000 × 15) / 480 = 15,000 / 480 = 31.25 ≈ 31 gtt/min (round to nearest whole number). Microdrip is often used in pediatrics because drops are smaller, allowing for more precise infusion control. When using gravity infusion, count the actual drops falling into the chamber and adjust the roller clamp to match the calculated rate every hour, as gravity-driven rates drift over time.

Intravenous fluids are classified by osmolality (particles per kilogram of solution) relative to plasma, which determines whether fluid shifts into or out of cells: (1) Isotonic fluids (osmolality 270–310 mOsm/kg, matching plasma): Examples: 0.9% Normal Saline (NaCl), Lactated Ringer's solution, and D5W (isotonic in the bag but becomes hypotonic after dextrose is metabolized). Effect: Fluid expands the extracellular volume without shifting fluid between compartments. Use: For fluid replacement and maintenance; safe for most patients, including those at risk for cerebral edema. (2) Hypotonic fluids (osmolality <270 mOsm/kg): Example: 0.45% NaCl. Effect: Fluid shifts INTO the cells (into the intracellular compartment); reduces extracellular osmolality. Use: For cellular dehydration and when replacing fluid losses (e.g., diarrhea); provide free water to cells. Caution: Risk of cerebral edema if given too rapidly; contraindicated in increased intracranial pressure (ICP) patients. (3) Hypertonic fluids (osmolality >310 mOsm/kg): Examples: 3% or 5% NaCl, D10W, or higher. Effect: Fluid is PULLED OUT OF cells into the vascular space; shrinks cell size. Use: To reduce cerebral edema, for severe hyponatremia, or to expand intravascular volume rapidly. Caution: Irritates peripheral veins; infuse slowly through a central line if possible; monitor for hypernatremia and fluid overload. Always use an infusion pump for hypertonic solutions. A common NLE trap: Students confuse which direction fluid moves; remember 'water follows salt and sugar'—fluid moves toward higher osmolality (hypertonic pulls out, hypotonic pushes in).

Certain medications carry high risk of serious harm if given in error and require additional safeguards: (1) Insulin—Rapid-acting (Humalog, Novolog) peaks in 1–2 hours; Short-acting regular insulin (NPH) peaks in 6–8 hours. Mnemonic for mixing: 'Clear before Cloudy' (draw clear/regular first, then cloudy/NPH). Always use insulin syringes (marked in units); DO NOT use regular syringes. Monitor blood glucose before and 2 hours after administration; rotate injection sites (abdomen preferred for more consistent absorption). Signs of hypoglycemia: sweating, tremor, tachycardia, anxiety, altered mental status. (2) Heparin and Low-Molecular-Weight Heparin (LMWH, e.g., enoxaparin/Lovenox)—Anticoagulants preventing thrombus formation. Heparin monitoring: aPTT (activated partial thromboplastin time) 1.5–2.5× normal baseline; target is 46–70 seconds depending on indication. LMWH does not require routine monitoring but watch for signs of bleeding (bruising, blood in urine/stool, nosebleeds). Antidote for heparin: Protamine Sulfate (reverses 80–90% of heparin effect within 5–10 minutes). DO NOT aspirate or massage the injection site after SC heparin/LMWH administration—this causes bruising. (3) Warfarin (Coumadin)—Oral anticoagulant; monitoring: PT/INR (prothrombin time/International Normalized Ratio); target INR usually 2–3 for most indications. Antidote: Vitamin K (reverses effect in 12–24 hours; slower than protamine). Drug interactions common (NSAIDs, antibiotics, aspirin increase bleeding risk). (4) Opioids (Morphine, Fentanyl, Hydrocodone)—Strong analgesics; risk: respiratory depression. Before administering, assess respiratory rate (RR); if RR <10–12 breaths/min, hold and reassess (per facility protocol). Antidote: Naloxone (Narcan)—reverses opioid effects within 1–2 minutes; may repeat every 2–3 minutes. Monitor for inadequate pain control and withdrawal symptoms after naloxone. (5) Potassium Chloride (KCl)—Critical electrolyte; NEVER give IV push undiluted because it can cause fatal cardiac arrhythmias (ventricular fibrillation). Always dilute in IV fluid; maximum concentration 40 mEq/L; infuse slowly (20–40 mEq/hr maximum, via pump, preferably through central line). Monitor EKG and serum potassium. (6) Chemotherapy drugs—High teratogenic and toxic potential; require special handling, verification, and patient teaching. (7) Neuromuscular blocking agents—Paralyze muscles; require ventilatory support; independent verification essential.

Complications of IV therapy range from minor to life-threatening and require prompt nursing recognition and intervention: (1) Infiltration—IV fluid leaks into surrounding subcutaneous tissue (NOT venous). Signs: swelling/edema around the IV site, coolness of the area, pale skin, decreased or stopped infusion flow, no blood return when aspirated. Management: STOP infusion immediately, remove the IV catheter, ELEVATE the limb above the heart, apply warm or cool compress depending on solution type (cold for potassium or hypertonic solutions to minimize absorption; warm for other solutions to promote reabsorption). Do NOT milk the IV line; do NOT inject additional solution. Restart IV in opposite limb. (2) Phlebitis—Inflammation of the vein; can be mechanical (catheter irritation), chemical (irritating solutions), or bacterial (infection). Signs: redness, warmth, pain along the vein; a palpable hard cord above the site. Management: Discontinue the IV, apply warm compress, elevate the arm, restart in another site. Prevent by: limiting catheter dwell time (change every 72–96 hours per CDC guidelines), maintaining aseptic technique, infusing compatible solutions only, and using appropriate flush solutions. (3) Extravasation—Leakage of a vesicant drug (e.g., chemotherapy, potassium, hypertonic solutions) into subcutaneous tissue; causes tissue necrosis and is a medical emergency. Signs: severe pain, swelling, tissue blanching. Management: STOP infusion, assess the extent, notify the physician immediately, apply ice to slow absorption, elevate the limb, document extensively, consider a medical event report. (4) Speed Shock—Rapid infusion of medication or fluid into the bloodstream, causing acute systemic reaction (chills, tachycardia, hypertension, syncope, shock). Management: STOP infusion immediately, slow to keep-vein-open (KVO) rate, place patient supine, notify physician. (5) Fluid Overload (Circulatory Overload)—Excess IV infusion in a patient with heart or renal disease, causing hypervolemia. Signs: dyspnea, orthopnea, crackles on lung auscultation, distended neck veins, bounding pulse, elevated blood pressure, weight gain. Management: Slow IV rate to KVO, raise the head of the bed to semi-Fowler's or higher, notify the physician, monitor vital signs and lung sounds, administer oxygen if ordered, monitor I&O carefully. (6) Air Embolism—Air bubble enters the vein, potentially blocking circulation and causing acute distress. Signs: sudden chest pain, dyspnea, hypotension, cyanosis, loss of consciousness (rare with small amounts). Management: Clamp IV tubing immediately, place patient on LEFT side in Trendelenburg position (traps air in right heart, away from pulmonary artery), notify physician, oxygen therapy, monitor closely. Prevent by: priming IV tubing fully, using IV pumps, checking lines for air. (7) Catheter-Related Bloodstream Infection (CRBSI)—Bacterial colonization of the catheter or insertion site. Signs: fever, chills, elevated WBC, positive blood cultures. Management: Remove the catheter, culture the tip, start IV antibiotics per physician order, maintain strict asepsis. (8) Hematoma—Blood collection from a damaged vessel during IV insertion or removal. Management: Apply direct pressure, elevate, apply ice (first 24 hours), then warm compress, monitor.

(1) Pediatric Patients: Doses are weight-based (mg/kg), not simply reduced versions of adult doses. Volumes are small (often <1 mL), leaving minimal room for calculation error. Always double-check calculations against published pediatric dose ranges and consult a pediatric dose reference. Use oral syringes (not needle syringes) for measuring and administering liquid medications to prevent accidental IV injection. Children may be unable to swallow pills; use crushable formulations, liquids, or chewables as available. Assess for developmental ability to cooperate. Use distraction and play techniques. Maximum injection volumes: infants <0.5 mL; toddlers ≤1 mL per site. Injection sites: For infants, vastus lateralis (outer thigh) is preferred over gluteal (not developed); for older children, ventrogluteal or vastus lateralis. (2) Older Adults (>65 years): Altered pharmacokinetics due to reduced hepatic metabolism and declining renal clearance (creatinine clearance decreases ~1% per year after age 30) mean drugs accumulate to higher levels and longer durations. Principle: 'Start low, go slow'—begin with the lowest effective dose and titrate gradually. Monitor renal and liver function tests; many drugs require dose adjustments. Polypharmacy (taking multiple drugs) increases risk of drug-drug interactions and adverse effects. Assess medication list regularly; discontinue unnecessary drugs. Increased risk of falls from orthostatic hypotension, CNS effects, or electrolyte imbalances. Older adults often have multiple comorbidities (diabetes, heart disease, kidney disease) affecting drug handling. Nutritional status and hydration impact absorption and distribution. (3) Pregnant Women: Principle: Avoid all medications in the first trimester if possible; most teratogens cause organ malformation during weeks 3–8. Consult drug category (FDA Category A = safest, rarely any fetal risk; B = probably safe; C = use only if benefits outweigh risks; D = positive fetal risk; X = contraindicated). Example: ACE inhibitors and NSAIDs contraindicated in pregnancy (especially second/third trimester, causing fetal renal dysfunction). Warfarin in first trimester increases fetal skeletal and CNS abnormalities ('fetal warfarin syndrome'). (4) Lactating Women: Many drugs transfer into breast milk; check compatibility before recommending continuation of breastfeeding. Some drugs (e.g., methotrexate, radioactive drugs) require cessation of breastfeeding. Others are considered safe (e.g., acetaminophen, most antibiotics). Educate mothers on timing: take the medication immediately after breastfeeding to allow maximum drug metabolism before the next feeding.

Accurate documentation is a legal and safety requirement under RA 9173 and Philippine nursing standards. Chart IMMEDIATELY AFTER administration, NEVER before—if you chart before giving and then do not give (due to patient refusal, new contraindication discovered), the medication record is falsified, which is a violation. Document: medication name, dose, route, time administered, site (for injections), patient response to the medication, and any adverse reactions or concerns. Example: '10:00 AM—Amoxicillin 500 mg PO given with water; patient swallowed without difficulty; no reported nausea.' If the patient refuses: Document the refusal, time, and action taken (notification to physician). Do NOT document that you gave the medication. If medication administration is delayed (e.g., held because vital signs contraindicate), document the reason and the time held. If a medication error occurs (wrong dose, wrong patient, wrong route, wrong time), the priority is PATIENT SAFETY: (1) Assess the patient immediately for signs of harm; (2) Notify the physician of the error and patient's current status; (3) Provide immediate intervention if indicated (e.g., if you gave double the intended dose of a narcotic, prepare to administer naloxone); (4) Complete an incident report per facility protocol—incident reports are educational and systems-focused, not punitive in a safe culture. Be honest and factual in the report. Involve the charge nurse and risk management. (5) Document the error, intervention, physician notification, and patient response in the patient's medical record. Do NOT blame others; focus on the error (not the person) and how systems can prevent recurrence. Most facilities have non-punitive error reporting to encourage disclosure and learning.

Certain medications have specific antidotes that reverse or neutralize their effects if toxicity or overdose occurs: (1) Heparin toxicity → Protamine Sulfate: Reverses unfractionated heparin anticoagulation; binds heparin and inactivates it. Dose: 1 mg protamine per 100 units heparin (base on last known heparin dose or blood levels if available). Onset: IV bolus within 5–10 minutes; watch for rebound anticoagulation 30 min–2 hours later. Monitor aPTT. (2) Warfarin (Coumadin) toxicity or over-anticoagulation → Vitamin K (Phytomenadione): Restores synthesis of clotting factors II, VII, IX, X. Onset: 12–24 hours (slower than protamine). Dose: 10–20 mg PO or IV (IV reserved for severe bleeding). Monitor PT/INR; may repeat after 12–24 hours. (3) Opioid toxicity (overdose, respiratory depression) → Naloxone (Narcan): Competitive opioid antagonist that reverses respiratory depression, sedation, and analgesia. Onset: IV 1–2 minutes; IM/SC 2–5 minutes; peak effect 5–15 minutes; duration ~30–60 minutes (shorter than many opioids, so repeat doses may be needed). Dose: Initial 0.4–0.8 mg IV; repeat every 2–3 minutes up to 10 mg. Caution: Sudden reversal triggers acute withdrawal (sweating, agitation, pain), but respiratory drive is restored. (4) Acetaminophen (Tylenol) toxicity → N-Acetylcysteine (Mucomyst): Replenishes hepatic glutathione, reducing liver damage from acetaminophen metabolite. Most effective if given within 24 hours of overdose (better within 8 hours). Dose and route depend on protocol; often given IV in acute toxicity. (5) Anticholinergic toxicity (e.g., atropine overdose) → Physostigmine: Cholinesterase inhibitor that reverses anticholinergic effects (mydriasis, urinary retention, tachycardia, confusion). (6) Benzodiazepine toxicity (overdose, respiratory depression) → Flumazenil: Competitive benzodiazepine antagonist. Use cautiously (risk of seizures, arrhythmias in benzodiazepine-dependent patients). (7) Iron overload/toxicity → Deferoxamine: Binds excess iron, allowing renal excretion. (8) Cyanide poisoning → Hydroxocobalamin or sodium nitrite/sodium thiosulfate.

Proper injection technique minimizes pain, infection risk, and tissue damage: (1) Intradermal (ID) Administration: Angle: 10–15° (shallow angle, almost parallel to skin). Needle size: 26–27 gauge, 3/8 to 5/8 inch. Volume: 0.1 mL maximum (0.05–0.1 mL typical). Site: Forearm (inner aspect), upper chest, or scapular area—areas with minimal hair and good visibility. Technique: Stretch skin taut, insert needle bevel-up, inject slowly to form a bleb (raised wheal); do NOT aspirate (risk of destroying the bleb). Used for: Allergy skin testing, tuberculin (Mantoux) testing. (2) Subcutaneous (SC/SQ) Administration: Angle: 45–90° depending on tissue depth; at 45° for thin people, 90° for people with more subcutaneous tissue. Needle size: 25–27 gauge, 1/2 to 5/8 inch. Volume: ≤1 mL maximum (0.5 mL typical); 1 mL is rarely exceeded. Sites: Abdomen (preferred for insulin—most consistent absorption; avoid 5 cm around the umbilicus), upper outer arm, anterior thigh, upper back. Technique: Pinch or spread skin to localize subcutaneous tissue, insert needle firmly and steadily, inject medication. For anticoagulants (heparin, LMWH): DO NOT aspirate (drawing back the plunger to check for blood)—aspiration can cause hematoma and is unnecessary. DO NOT massage the injection site—massage causes bruising and increases hematoma risk. Use a new needle if the needle has touched the rubber septum of the vial (dulled needle causes tissue trauma). Rotate sites at least 1 inch apart to prevent lipodystrophy (fat atrophy or hypertrophy). (3) Intramuscular (IM) Administration: Angle: 90° (perpendicular to skin). Needle size: 20–25 gauge, 1–1.5 inches for adults; 5/8–1 inch for deltoid (smaller muscle). Volume: Up to 3 mL in large muscles (ventrogluteal, vastus lateralis); ≤1 mL in deltoid. Sites: • Ventrogluteal (preferred for adults): Locate by placing the heel of the hand on the patient's greater trochanter, fingers on the anterior superior iliac spine, and injecting in the V formed by the index and middle fingers. Advantages: away from nerves and major blood vessels, well-developed muscle, acceptable to patients, painless. • Vastus lateralis (preferred for infants and children): Outer lateral aspect of the thigh, midway between greater trochanter and lateral epicondyle of the femur. Advantages: easily accessible in infants, away from nerves/vessels. • Deltoid: Upper arm, posterior to the acromion process. Limitations: small muscle; use only for small volumes (≤1 mL), vaccines, and some antibiotics. Risk of hitting the radial and axillary nerves and vessels if injected too medially or low. • Dorsogluteal (AVOIDED for new injections): Posterior buttock; risk of sciatic nerve damage, causing paralysis or chronic pain. Used only in exceptional circumstances (large volumes in adults) and only if provider is experienced. Technique: Cleanse with alcohol; insert needle at 90°; aspirate (draw back the plunger) to check for blood return indicating a vessel; if blood is aspirated, WITHDRAW NEEDLE, discard syringe, and prepare a new injection at a different site. If no blood is returned, inject medication slowly (3–5 seconds per mL). Some sources recommend aspiration during IM injection to avoid intravascular injection of oil-based or irritating medications; others say aspiration is not necessary for most drugs given today. Follow facility protocol. (4) Z-Track Technique (for irritating or staining drugs like iron dextran, hydroxyzine): Pull the skin laterally about 1–1.5 inches, then insert the needle at 90°, inject, wait 10 seconds, withdraw the needle, and release the skin—the tissue moves back, sealing the track and preventing drug leakage into the subcutaneous layer (which would cause tissue damage, staining, or pain). Used to prevent pain and tissue irritation from intramuscular injections of certain medications.

The Institute for Safe Medication Practices (ISMP) and Philippine nursing standards prohibit certain abbreviations and dose-writing practices because they have caused serious medication errors: (1) Prohibited abbreviations: • 'U' for units—often misread as '0' (zero) or '4' (four). Always write 'units' in full. Example: Write 'insulin 10 units' NOT '10 U'. • 'IU' for International Units—prone to misreading. Write 'International Units' or abbreviate as 'IU' only if absolutely required by facility. • 'QD' (once daily) and 'QOD' (every other day)—misread as 'QID' (four times daily). Write 'daily' or 'every other day' in full. • 'SC' or 'SQ' (subcutaneous)—can be confused. Use 'subcut' or write 'subcutaneous'. • 'MS' (morphine sulfate) and 'MSO4'—confused with magnesium sulfate (MgSO4), a different drug. Write 'morphine sulfate' in full. • 'APAP' for acetaminophen—unfamiliar to many readers. Write 'acetaminophen' or 'Tylenol'. (2) Dose-writing standards: • Use a LEADING ZERO for doses <1 mg. Write '0.5 mg' NOT '.5 mg' (a decimal point alone can be missed, leading to a 10-fold error). • NEVER use a TRAILING ZERO after a decimal point. Write '5 mg' NOT '5.0 mg' (the zero can be misread as causing a 10-fold overdose). • Write fractions as decimals or whole numbers where possible. If a fraction is necessary, use '1/2' not '½' (symbol may not print correctly). • Use the metric system exclusively; avoid apothecary (gr, dr, minim) and household (tsp, tbsp) measures except in patient-facing instructions. • Milligrams and micrograms: Write 'mg' and 'mcg' (NEVER 'µ' or 'μ' symbols, which may not print correctly in electronic systems). • Always include units. Write '10 mg' NOT '10' (units omitted has caused serious errors).

Teaching patients about their medications supports adherence, self-management, and early recognition of adverse effects. Key elements: (1) Drug Name and Purpose: Teach both generic and brand names (e.g., 'This is your blood pressure medication called lisinopril, brand name Prinivil'). Explain what the medication does in simple terms (e.g., 'This helps your heart pump more efficiently' rather than 'ACE inhibitor lowers afterload'). (2) Dose and Timing: Explain the amount and frequency in clear language. Provide a written medication list in the patient's preferred language (Tagalog, Cebuano, Ilocano, etc.). Use a pill organizer or medication reminder apps if helpful. For antibiotics, emphasize completing the full course even if feeling better (non-compliance leads to antibiotic resistance, a critical public health concern in the Philippines under DOH DOTS—Directly Observed Therapy Short-course for TB). (3) Common Side Effects vs. Serious Adverse Effects: Teach expected, mild side effects (e.g., 'You may feel slightly dizzy at first when starting this blood pressure medication') and serious effects requiring immediate attention (e.g., 'Seek help if you have chest pain, difficulty breathing, or severe dizziness'). (4) Food and Drug Interactions: Example: 'Take this on an empty stomach' or 'Avoid grapefruit juice with this statin' or 'Do not mix with antacids.' For oral anticoagulants: Teach consistent vitamin K intake (found in leafy greens) to maintain stable INR. (5) Storage and Handling: 'Keep at room temperature, away from heat and moisture' (not in the bathroom where humidity degrades tablets). Insulin storage: refrigerate unopened vials; once opened, keep at room temperature for 28 days. (6) Adherence Support: For patients on multiple medications (polypharmacy), use a pill organizer with labeled compartments. Assess barriers to adherence (cost, side effects, complexity, forgetfulness). Consider twice-daily rather than four-times-daily regimens for improved adherence. Use teach-back method: 'Please tell me back when you will take your medication and what you are hoping it will do for you.' (7) Cultural Sensitivity: Filipino patients may consult traditional healers (albularyo) or use herbal supplements (ginger, garlic, turmeric); ask about these openly without judgment and address potential herb-drug interactions. Family involvement is valued in Filipino culture; include family in teaching whenever possible. (8) Follow-up and Monitoring: 'Please keep your lab appointments so we can check if this medication is working' (especially for digoxin levels, INR for warfarin, glucose for insulin). Teach when to contact the physician or nurse (persistent side effects, signs of toxicity, new symptoms).