Pharmacologic and Non-pharmacologic Interventions: Mechanism Over Memorization
Four filters before you prescribe
Pharmacology items rarely ask for a drug list; they ask why a regimen is wrong for this patient. Sort each decision through clearance (dose-adjust using Cockcroft-Gault creatinine clearance, using actual body weight and the 0.85 factor for women), interactions (CYP3A4 inhibitors such as clarithromycin, azole antifungals, and grapefruit raise levels of statins, calcium channel blockers, and many direct oral anticoagulants), age (Beers criteria: avoid benzodiazepines, anticholinergics, and long-acting sulfonylureas in older adults), and pregnancy or lactation status.
High-yield classes
Know anticoagulant selection by indication (CHA2DS2-VASc for atrial fibrillation; mechanical valves require warfarin), insulin initiation and titration, inhaler technique and step therapy, antibiotic selection with de-escalation, opioid equianalgesia and bowel prophylaxis, and the monitoring that makes a drug safe - AUC-guided vancomycin, anti-Xa monitoring for heparin in obesity or kidney disease, INR for warfarin.
Non-pharmacologic therapy is testable
Sodium and fluid restriction in heart failure, pulmonary rehabilitation, cognitive behavioral therapy for insomnia, physical therapy for low back pain, and vaccination as secondary prevention all appear as correct answers. Deprescribing is a legitimate plan: stopping the drug that is causing the problem is often the best intervention.
Worked rule of thumb
A 78-year-old woman weighing 60 kg with serum creatinine 1.2 mg/dL needs a renally cleared drug. Clearance equals (140 minus 78) times 60, divided by (72 times 1.2), times 0.85, or about 37 mL/min - use the moderate-impairment dosing column and reassess after any clinical change.