Medication Routes and Dosages
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Direct answer
Medications reach the body through enteral routes (oral, sublingual, buccal, nasogastric, rectal), parenteral routes (intravenous, intramuscular, subcutaneous, intradermal) and topical or local routes (skin patches, inhaled, instillations). Safe administration rests on the rights of medication — right patient, drug, dose, route, time and documentation, often extended to right reason, response and refusal. The core calculation is: amount to give equals desired dose divided by available strength, multiplied by the volume it comes in.
What you must remember
- Intravenous administration acts fastest and most completely; oral is safest and commonest but unsuitable in vomiting, coma or malabsorption; sublingual and buccal routes bypass first-pass metabolism (glyceryl trinitrate).
- Verify every prescription — drug, dose, route, frequency, duration; question illegible or unsafe orders before administering.
- Check the rights at the bedside with two patient identifiers, keep high-alert drugs (insulin, heparin, concentrated potassium, narcotics) for independent double checks, and store look-alike, sound-alike drugs apart.
- Dose calculation: desired dose divided by stock strength, times stock volume — 250 mg ordered from a vial of 500 mg in 2 mL gives 1 mL.
- Drip rate: drops per minute equals total volume times the drop factor divided by minutes; macro sets deliver 10, 15 or 20 drops per mL, micro (burette) sets 60.
- Infusion pumps deliver mL per hour (volume divided by hours); syringe pumps serve precise small-volume drugs such as inotropes.
- Document immediately after administration, monitor response, teach the patient the drug's purpose, and report adverse reactions — insulin, anticoagulants and antibiotics are classic favourites.
Common confusion
Sublingual and buccal get interchanged — a sublingual tablet dissolves under the tongue, a buccal one against the cheek, and neither is swallowed. Students also confuse micro and macro drip factors, which are printed on the giving set. Calculation errors usually come from unit mismatch — convert grams, milligrams and micrograms to one unit before dividing. Finally, in most modern lists the sixth right is documentation, not technique.
Exam-focused takeaway
A numerical question on dose or drip rate is near-certain, so drill the two formulas and unit conversion (1 g = 1000 mg; 1 mg = 1000 micrograms). Scenario questions test the rights — an order without a route, two similar names, a dose outside range — where the answer is to withhold and clarify. Know the routes' onset hierarchy, the high-alert list and the legal principle that the nurse who gives the drug remains accountable even for a wrong prescription.
Frequently asked questions
What are the rights of medication administration?
The classical five — patient, drug, dose, route and time — commonly expanded to include documentation, reason, response and the patient's right to refuse.
How is a dose calculated?
Divide the desired dose by the strength available and multiply by the volume or number of tablets it comes in — desired over stock, times vehicle.
How is the drip rate calculated?
Drops per minute equals total volume times the set's drop factor divided by minutes — 1000 mL over 8 hours with a 20 drops per mL set gives about 42 drops per minute.
Which route has the fastest onset?
Intravenous, entering the circulation directly; sublingual is fastest among non-injectable routes.
What must the nurse do if an order seems unsafe?
Withhold the drug, check with the prescriber and document the communication — administering a clearly erroneous order still leaves the nurse accountable.