Design, Implementation, Monitoring, and Modification of Pharmacotherapy
Start with the patient and the goal
Oncology regimen selection is not a memory exercise alone. Confirm histology, stage, biomarkers, performance status, organ function, prior therapy, and treatment intent (curative, adjuvant, palliative). Match the regimen to evidence and patient goals. Calculate doses using current weight/BSA, verify capping, and adjust for renal/hepatic function and interactions.
Concepts to master
Dose intensity, dose density, BSA capping, renal dosing (Cockcroft-Gault vs Calvert), hepatic classification, CYP3A4/P-gp interactions, emetogenicity, premedications, growth-factor use, and response/toxicity monitoring. Know cumulative limits (anthracyclines, bleomycin, cisplatin) and when to hold, reduce, or change therapy.
Common traps
Questions often hinge on a detail: capping BSA in obesity, using actual vs adjusted body weight, confusing carboplatin Calvert with AUC dosing by creatinine clearance, missing an interacting drug (azole, anticonvulsant, warfarin), or modifying therapy for a toxicity without grading it. Do not reduce dose for a non-dose-limiting lab abnormality; do not continue a regimen after documented progression if intent is palliative.
Worked rule
For carboplatin, total dose (mg) = target AUC × (GFR + 25), with GFR capped per protocol; do not substitute BSA-based dosing. For any regimen, state intent, verify protocol, calculate dose, screen interactions, then set monitoring.
Rule of thumb: treat the patient and the protocol together-if a dose must change, document the toxicity grade, rationale, and monitoring plan.