Pharmacology and Medication Safety: Rights, Calculations, and Reporting
What this domain tests
Drug routes, dosage calculation, the rights of medication administration, adverse effects, and safe storage.
Core rules and concepts
- Rights: right patient, drug, dose, route, time, and documentation. Many add right reason and right to refuse.
- Check the label three times: when removing, when preparing, and when administering.
- Use the metric system. Convert units before calculating. 1 g = 1,000 mg; 1 mg = 1,000 micrograms; 1 L = 1,000 mL.
- Oral drugs are usually slower than IV; IV drugs act fastest but carry higher risk.
- Report adverse drug reactions. Keep high-alert drugs such as insulin and heparin double-checked.
Worked example
Order: 250 mg. Stock: 500 mg in 5 mL. Volume = (desired dose / stock dose) × stock volume = (250/500) × 5 = 0.5 × 5 = 2.5 mL. Reasoning: set up the proportion so units cancel. Check that 2.5 mL is measurable with the available syringe; if not, ask for a different preparation rather than guessing.
Traps that cost marks
- Writing "5.0 mg" instead of "5 mg"; the trailing zero can be misread.
- Confusing mg and micrograms.
- Calculating with the stock volume as the numerator.
- Administering a drug prepared by someone else without checking.