Formula sheets, the key method steps for every topic and 6 practice problems, with full solutions at the back.
A patient receiving chemotherapy has a very low neutrophil count and is going home. Which teaching is most important?
Why can beta blockers mask the warning signs of hypoglycaemia in people with diabetes?
A child weighing 40 kg is prescribed 2 mg/kg of a drug. The stock solution contains 20 mg/mL. Draw up the dose: what volume V do you give?
A patient is 166 cm tall and weighs 81 kg. The prescription is 75 mg/m². Using the Mosteller formula BSA = √(height (cm) × weight (kg)/3600), find the dose D in mg.
Practice exercise (made-up values, not clinical guidance). A patient receives an IV bolus of 100 mg of tobramycin. The level back-extrapolated to time zero is 6 mg/L and the half-life is 2.5 h. Find the clearance CL in L/h.
Practice exercise (made-up values, not clinical guidance). A 50 kg patient takes oral aminophylline (S = 0.8, F = 1) every 8 h. The theophylline clearance is 0.035 L/kg/h. What dose D in mg gives an average steady-state level of 12 mg/L?
Answer: C · Report a temperature of 38 °C (100.4 °F) or higher straight away
Neutropenic patients may have few signs of infection other than fever, and sepsis can develop quickly. A fever needs urgent assessment; good hand hygiene and avoiding sick contacts are also taught.
Answer: B · They blunt adrenergic symptoms such as tremor and palpitations
Tremor, palpitations and anxiety in hypoglycaemia are adrenaline-driven; beta blockade dampens them, so patients may notice low glucose later. Sweating is cholinergic and often persists.
Answer: V = 4 mL
Drawing up a dose: volume = (prescribed dose/stock strength) × stock volume. Convert to the same units first, then check that the volume fits the syringe and lands on one of its graduations.
On this 10 mL syringe every small line is 0.2 mL.
Answer: D = 144.9 mg
Body-surface-area dosing: many cytotoxic and some paediatric doses are prescribed per square metre of body surface area: dose (mg) = dose per m² × BSA (m²). The Mosteller formula estimates BSA = √(height (cm) × weight (kg)/3600).
Answer: CL = 4.621 L/h
Clearance and volume: at steady state the dosing rate equals the elimination rate, so the maintenance rate = CL × Css. A loading dose is LD = Vd × C/(S × F), with S the salt factor (fraction of active drug in the salt) and F the bioavailability (1 for IV). From two levels, k = ln(C₁/C₂)/Δt; for an IV bolus Vd = dose/C₀ and CL = k × Vd. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
Answer: D = 210 mg
Designing a regimen: with rapid IV doses the level falls from peak to trough during the interval, so τ = ln(Cpeak/Ctrough)/k and the dose that restores the peak is Vd × (Cpeak − Ctrough). The average steady-state level is Css,avg = S·F·dose/(CL·τ). An infusion rises as C = (R/CL)(1 − e−kt). For a drug cleared by the kidneys, the dose is scaled with the creatinine clearance. The numbers are for practice only; at the bedside always follow local protocols and have high-risk doses double-checked.
ExamProblems · examproblems.com/courses/pharmacology