Pharmacology and Nursing Management of Drugs
Pharmacology and nursing management of drugs tests drug classes, mechanisms of action, adverse effects, interactions, safe administration and dosage calculations. Nursing items often ask which parameter to monitor or which action prevents harm.
Core rules
- Pharmacokinetics describes absorption, distribution, metabolism and excretion. First-pass hepatic metabolism reduces oral bioavailability; the half-life determines dosing interval.
- High-alert medicines include insulin, heparin, opioids, potassium chloride and chemotherapy. Use independent double-checks, standard concentrations and clear labelling.
- Aminoglycosides (gentamicin) are ototoxic and nephrotoxic; monitor renal function and peak/trough levels. Vancomycin requires therapeutic drug monitoring. Penicillins can cause anaphylaxis.
- Never give potassium chloride by IV push; dilute and infuse with cardiac monitoring. Check the apical pulse before digoxin and withhold if below 60/min in adults unless prescribed.
- Calculation: volume to give = (desired dose ÷ stock dose) × stock volume. Convert all units to the same system first.
Worked example
Order: 500 mg. Stock: 1 g in 10 mL. Convert 1 g to 1000 mg. Volume = (500 ÷ 1000) × 10 = 5 mL. Reasoning: using the same units prevents a tenfold error; dimensional analysis gives the same answer.
Traps
Confusing mg and mcg; dividing by the stock volume instead of multiplying; ignoring renal function when gentamicin is ordered; giving potassium chloride undiluted; administering digoxin without checking the pulse.