Pharmacology and Medication Administration
What the domain tests
This domain tests safe preparation, the rights of administration, calculation accuracy, route selection, and recognition of adverse effects. Expect calculation items (weight-based, pediatric, unit conversion) and scenario items about a discrepancy or a refusal.
Core rules
- The rights: right patient, drug, dose, route, time, and documentation, plus reason and the right to refuse. Verify with two identifiers and check the label against the order at least three times: when pulling, when preparing, and at the bedside.
- Convert before you calculate: 1 g = 1,000 mg; 1 mg = 1,000 mcg; 1 L = 1,000 mL; 1 kg = 2.2 lb. Dose = (desired / have) x quantity.
- Assess before you give: allergies, current medications, pertinent vital signs, and the indication. Recheck the label at the bedside.
- Route distinctions: intradermal (5-15 degrees, bevel up, forearm, tuberculin syringe), subcutaneous (45-90 degrees, 25-27 G, abdomen or thigh), intramuscular (90 degrees, ventrogluteal preferred in adults), intravenous.
- Never administer a medication prepared by someone else without verifying the label and the order. High-alert drugs such as insulin, heparin, opioids, and concentrated electrolytes require an independent double-check.
- Avoid error-prone abbreviations: U for units, qd and qod, MS for morphine sulfate, trailing zeros (write 5 mg, not 5.0 mg), and missing leading zeros (write 0.5 mg).
- Store drugs per label, keep vaccines within the cold chain, and never give an expired or discolored product. Document immediately after administration; if a dose is withheld, record the reason and notify the provider.
Worked example
Order: 0.25 mg of a drug; stock: 0.5 mg per 2 mL. Reasoning: (0.25 / 0.5) x 2 mL = 0.5 x 2 = 1 mL. Confirm the units match, that 0.25 mg is safe for the patient's weight, and that the ordered route matches the preparation before drawing up. Answering 2 mL means the ratio was inverted.
Traps that cost marks
- Calculating before converting units.
- Accepting a verbal order for a high-alert drug without a read-back.
- Using an unlabeled syringe or a drug prepared by another person.
- Documenting a dose before it is actually given.