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📋 ADMINISTRATION OF MEDICATIONS

Nursing Student Notes

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1. INTRODUCTION - KEY DEFINITIONS

• Medication = Any substance given to diagnose, treat, cure, or prevent disease. It can be natural (plant/animal) or synthetic (lab-made). Also called a drug.
• Administration of Medication = The act of giving a medication to a patient using the correct route, dose, time, and technique as ordered by a doctor.
• Drug Nomenclature = Every drug has 3 names: Chemical name (exact formula), Generic name (official/common name, e.g., paracetamol), and Brand/Trade name (manufacturer's name, e.g., Calpol).
• Pharmacodynamics vs Pharmacokinetics = Pharmacodynamics is what the drug does to the body (mechanism of action, effects). Pharmacokinetics is what the body does to the drug - Absorption, Distribution, Metabolism, Excretion (ADME).

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2. EFFECTS OF DRUGS

• Therapeutic Effect = The desired/intended effect of the drug (e.g., paracetamol reducing fever).
• Side Effect = An unintended but predictable effect (e.g., drowsiness with antihistamines). Not always harmful.
• Adverse/Toxic Effect = A harmful, unintended effect that may be dangerous (e.g., liver damage from overdose of paracetamol).
• Idiosyncratic / Allergic Reaction = An abnormal, unexpected reaction unique to a specific patient (e.g., anaphylaxis from penicillin).

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3. FORMS OF MEDICATIONS

• Solid forms: Tablets, capsules, powders, suppositories - for oral or rectal use. Easy to store and transport.
• Liquid forms: Syrups, suspensions, elixirs, injections - easier to swallow and absorb faster than solids.
• Semi-solid forms: Creams, ointments, gels, lotions - applied topically to skin or mucous membranes.
• Gaseous/Inhaled forms: Aerosols, inhalers, nebulizers - delivered through the respiratory tract for local or systemic effect.

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4. PHARMACODYNAMICS & PHARMACOKINETICS (ADME)

• Absorption = Drug moves from the site of administration into the bloodstream. Affected by route, blood flow, and drug formulation.
• Distribution = Drug travels through blood to target tissues and organs. Depends on blood flow, protein binding, and drug solubility.
• Metabolism = Drug is chemically changed (mainly in the liver) into active or inactive forms. The "first-pass effect" reduces oral drug effectiveness.
• Excretion = Drug or its metabolites are removed from the body mainly through kidneys (urine). Also via bile, sweat, breast milk, and lungs.

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5. FACTORS INFLUENCING MEDICATION ACTION

• Age & Weight = Children and elderly need lower doses. Weight-based dosing (mg/kg) is used especially in pediatrics.
• Route of Administration = IV acts fastest; oral is slowest. Route affects speed and intensity of drug action.
• Patient's Health Status = Liver/kidney disease slows drug metabolism and excretion, causing drug buildup and toxicity risk.
• Drug Interactions = Two drugs taken together can increase, decrease, or cancel each other's effects (e.g., antacids reduce antibiotic absorption).

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6. MEDICATION ORDERS & PRESCRIPTIONS

• A valid prescription must include: patient name, date, drug name, dose, route, frequency, and prescriber's signature.
• Types of orders: Routine (regular schedule), PRN (as needed), STAT (immediately), Single dose (one time only).
• The nurse must read, verify, and question any unclear or suspicious orders before administering the drug.
• Verbal/telephone orders should be written down, read back to confirm, and signed as soon as possible per hospital policy.

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7. SYSTEMS OF MEASUREMENT

• Metric System (most common in healthcare): uses grams (g), milligrams (mg), micrograms (mcg), milliliters (mL), and liters (L).
• Household System: teaspoons (tsp), tablespoons (tbsp), cups - used for home medicine but not precise for clinical use.
• Apothecary System (older, rarely used): grains, drams, minims - sometimes seen on old prescriptions.
• Key conversions: 1 g = 1000 mg, 1 mg = 1000 mcg, 1 kg = 2.2 lbs, 1 tsp = 5 mL, 1 tbsp = 15 mL.

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8. MEDICATION DOSE CALCULATION

• Basic formula: Dose to give = (Desired dose ÷ Dose on hand) × Volume on hand
• Weight-based: Dose = Weight (kg) × mg/kg ordered - used commonly in pediatric patients.
• IV drip rate: Drops per minute = (Volume in mL × Drop factor) ÷ Time in minutes
• Always double-check calculations and verify with a second nurse for high-alert drugs like insulin, heparin, and chemotherapy.

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9. PRINCIPLES - 10 RIGHTS OF MEDICATION ADMINISTRATION

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10. ERRORS IN MEDICATION ADMINISTRATION

• Types of errors: Wrong drug, wrong dose, wrong patient, wrong route, omission (missed dose), extra dose, or wrong time.
• Common causes: Illegible handwriting, look-alike/sound-alike drugs, poor communication, distraction, fatigue, and skipping the 10 rights.
• If an error occurs: Assess the patient immediately, notify the doctor, document the error honestly, and fill out an incident report.
• Prevention: Use barcoding systems, double-checks for high-alert drugs, clear labeling, and proper handoff communication.

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11. ROUTES OF ADMINISTRATION

• Enteral routes = Through the GI tract - oral, sublingual, buccal, nasogastric, rectal. Safest but slowest onset.
• Parenteral routes = Bypassing the GI tract - IM, IV, SC, ID. Faster absorption, used when oral is not possible.
• Topical routes = Applied to skin or mucous membranes for local effect (creams, drops, patches).
• Inhalation = Drug inhaled into lungs for local (asthma) or systemic effect. Fast acting due to large lung surface area.

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12. STORAGE & MAINTENANCE OF DRUGS / NURSE'S RESPONSIBILITY

• Store drugs in cool, dry, and dark places. Some drugs (insulin, vaccines) need refrigeration (2-8°C). Never store near heat or sunlight.
• Controlled substances (narcotics) must be kept in double-locked cabinets with a count recorded at every shift change.
• Check expiry dates regularly. Expired or deteriorated drugs (color change, precipitate, unusual odor) must be discarded per protocol.
• Nurse's responsibility: Know drug actions, check orders carefully, monitor patient, document accurately, and report any adverse reactions.

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13. TERMINOLOGIES & ABBREVIATIONS IN PRESCRIPTIONS

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14. DEVELOPMENTAL CONSIDERATIONS

• Infants/Children: Smaller doses (weight-based), liquid forms preferred, use child-friendly technique (distraction, praise), involve parents.
• Adolescents: Respect privacy, explain purpose of medication, watch for non-compliance (secretly spitting out tablets).
• Adults: Confirm patient understanding of medication, assess ability to self-medicate, check for allergies and interactions.
• Elderly: Slower metabolism and excretion means higher risk of toxicity. Use "Start Low, Go Slow" principle. Check swallowing ability and polypharmacy.

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15. ORAL, SUBLINGUAL & BUCCAL ROUTES

• Oral (PO): Swallowed and absorbed via GI tract. Safest and most convenient. Tablets, capsules, syrups. Do NOT crush enteric-coated or sustained-release tablets.
• Sublingual (SL): Placed under the tongue - dissolves rapidly and absorbs directly into bloodstream (e.g., GTN for angina). Acts in 1-3 minutes. Patient must not swallow it.
• Buccal: Placed between gum and cheek. Slower than SL but still bypasses liver first-pass. Patient must not eat or drink while in place.
• Equipment needed: Medication cup, water, straw (if needed), gloves. Always stay with the patient until medication is swallowed/absorbed.

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16. PARENTERAL ADMINISTRATION - SITES & COMPARISON

• ID Technique: Bevel up, 10-15° angle, raise a wheal (bleb). Do NOT massage.
• SC Technique: 45-90° angle. Pinch skin. Rotate sites to prevent lipodystrophy.
• IM Technique: Z-track method preferred - prevents drug leakage into subcutaneous tissue.
• IV Technique: Confirm placement before infusion. Check for infiltration (swelling, coolness), phlebitis (redness, warmth, pain).

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17. EQUIPMENT - SYRINGES, NEEDLES & INFUSION SETS

• Syringe parts: Plunger, barrel (with calibration markings), tip (Luer-lock or slip-tip). Sizes: 1mL (tuberculin), 3mL, 5mL, 10mL, 20mL, 50mL.
• Needle parts: Hub (attaches to syringe), shaft/cannula (length), bevel (angled tip - shorter bevel = less pain). Gauge = thickness (higher gauge = thinner needle).
• IV cannula (IV catheter): Flexible plastic catheter inserted into vein. Sizes: 14G (trauma/blood), 18-20G (routine IV), 22-24G (children/elderly).
• Infusion sets: Macro-drip (10, 15, or 20 drops/mL) for large volumes; Micro-drip (60 drops/mL) for precise/pediatric doses. Parts include spike, drip chamber, roller clamp, and needle adapter.

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18. VIALS & AMPOULES - PREPARATION OF INJECTABLE MEDICINES

• Ampoule: Glass container with a single dose - snap open the neck after filing. Draw up with a filter needle to avoid glass particles.
• Vial: Rubber-top glass bottle (single or multi-dose). Clean the rubber top with an alcohol swab, inject air equal to the dose needed, then withdraw the drug.
• Reconstitution: Some drugs (e.g., powdered antibiotics) need to be dissolved in a diluent (sterile water or normal saline). Roll gently - do NOT shake vigorously (causes foaming).
• Aseptic technique is mandatory: Use sterile equipment, clean the site, work quickly once the vial is opened, and label multi-dose vials with date/time of opening.

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19. CARE OF EQUIPMENT - DECONTAMINATION & DISPOSAL

• Single-use items (syringes, needles, IV cannulas) must NEVER be reused - risk of infection and needle-stick injury.
• Sharps disposal: All needles, lancets, and broken ampoules go directly into a rigid, puncture-proof sharps container (yellow/red). Never recap needles with two hands.
• Infusion sets: Change every 72-96 hours (or per hospital policy). Change immediately if blood products or lipids are infused.
• Decontamination: Reusable equipment (e.g., IV stands, trays) cleaned with detergent, then disinfected with 70% alcohol or hospital-grade disinfectant before reuse.

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20. PREVENTION OF NEEDLE-STICK INJURIES (NSI)

• Never recap a used needle with two hands - use the one-hand scoop method if recapping is absolutely necessary.
• Dispose of sharps immediately after use into a clearly labeled, puncture-resistant sharps bin. Never overfill beyond the fill line (usually 3/4 full).
• If a needle-stick occurs: Wash site with soap and water, bleed freely (do NOT suck), report immediately, and follow the hospital's post-exposure prophylaxis (PEP) protocol.
• Wear appropriate PPE (gloves) when handling sharps, and attend regular training on safe injection practices.

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21. TOPICAL ADMINISTRATION

• Application to skin & mucous membranes: Creams, ointments, gels, lotions, transdermal patches applied to intact skin. Use gloves to avoid self-absorption. Rotate patch sites.
• Direct application: Liquids applied directly to throat area (gargles for sore throat, swabbing with antiseptic). Patient gargles without swallowing.
• Insertion into body cavities: Suppositories inserted into rectum (patient in left lateral/Sims' position) or vagina (medicated packing). Wear gloves, use lubricant.
• Instillations = Dropping liquid medication into the eye (head tilted, lower conjunctival sac), ear (straighten canal - pull pinna up and back in adults, down and back in children), nose (head hyperextended), or bladder.

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22. IRRIGATIONS

• Irrigation = Flushing a body cavity with a solution - different from instillation (which just deposits drug).
• Eye irrigation: Flush from inner canthus outward using normal saline or prescribed solution (for chemical burns, foreign bodies).
• Ear irrigation: Warm solution (at body temp to avoid vertigo). Contraindicated if tympanic membrane is perforated.
• Bladder, vaginal, and rectal irrigations: Use sterile or clean technique per order. Monitor volume in vs volume out and patient comfort throughout.

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23. INHALATION ROUTE

• Purpose: Delivers medication directly to airways/lungs for respiratory conditions (asthma, COPD) or systemic effects. Also delivers steam, oxygen, and anaesthetic gases.
• Types of devices: Metered-Dose Inhaler (MDI), Dry Powder Inhaler (DPI), Nebulizer (converts liquid to fine mist), endotracheal/tracheostomy tube administration in ventilated patients.
• Procedure: Patient sits upright, exhales fully, seals lips around mouthpiece, inhales slowly and deeply, holds breath 10 seconds, then exhales. Spacer devices help patients who can't coordinate.
• Recording & Reporting: Document drug name, dose, time, route, patient response (SpO2 before and after, breath sounds), and any adverse effects (tremor, tachycardia from salbutamol).

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24. OTHER PARENTERAL ROUTES

• These routes carry higher risk than standard routes and are typically performed by doctors or advanced practice nurses only.
• As a nurse, your role is to monitor the patient closely for complications (bleeding, infection, misplacement) and document accurately.

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📌 QUICK MEMORY AIDS

ADME = Absorption, Distribution, Metabolism, Excretion (pharmacokinetics)

10 RIGHTS = Patient, Drug, Dose, Route, Time, Documentation, Reason, Refusal, Assessment, Evaluation

Needle Bevel Rule = ID (bevel UP, 10-15°) → SC (45-90°) → IM (90°, Z-track)

IV Gauge Rule = Bigger emergency = Smaller gauge number (14G is widest)

Ear instillation: Adults = pull pinna UP and BACK | Children = pull pinna DOWN and BACK

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