Pharmacology and Medication Management
Foundations
Medication administration rests on the rights (patient, drug, dose, route, time, documentation, reason), the three checks, and independent double-checks for high-alert drugs such as insulin, heparin, opioids, chemotherapy, and concentrated electrolytes. Assess before you administer: apical pulse before digoxin, blood pressure before antihypertensives, potassium before digoxin and before replacement, respiratory rate and sedation level before opioids.
Monitoring and antidotes
Digoxin 0.5–2 ng/mL; lithium 0.6–1.2 mEq/L; phenytoin 10–20 mcg/mL; warfarin INR 2–3. Antidotes: heparin–protamine sulfate, warfarin–vitamin K, opioids–naloxone, benzodiazepines–flumazenil, acetaminophen–acetylcysteine, digoxin–digoxin immune Fab. Recognise serotonin syndrome (clonus, hyperreflexia, fever, SSRIs), neuroleptic malignant syndrome (rigidity, high fever, autonomic instability), and lithium toxicity (tremor, vomiting, ataxia).
Traps
'Which should the nurse do first?' - assessment usually precedes holding a dose or calling the prescriber. Watch for look-alike and sound-alike names, never crush extended-release tablets, and respect IV push rates. A value normal for one patient may be abnormal for another (a beta-blocked patient may tolerate a heart rate of 50).
Worked rule
Dose calculation: desired ÷ have × volume, then sanity-check the result against the site and syringe size. 0.5 g ordered from 1 g in 2 mL equals 1 mL - not 0.1 mL or 10 mL. If the volume looks implausible, recheck the decimal.