Pharmacy and Pharmacology
Pharmacy and pharmacology on the MA Vet Tech exam tests how drugs move through the body, how they are dispensed, stored, and documented, and how doses are calculated and explained to clients. Expect questions on drug classes, routes, adverse effects, controlled-substance rules, and applied math.
Core rules and concepts
- Pharmacokinetics has four phases: absorption, distribution, metabolism (mostly hepatic), and excretion (mostly renal). Half-life sets the dosing interval and the time to steady state, about five half-lives.
- Know major classes and cautions: NSAIDs inhibit COX and are avoided in GI ulceration, dehydration, or renal disease; corticosteroids suppress inflammation but can worsen diabetes; bactericidal antibiotics kill while bacteriostatic drugs inhibit growth.
- In the US, controlled substances follow DEA schedules II–V. Schedule II drugs require secure storage and separate ordering; every schedule needs a running log with date, patient, amount, and initials. Correct a log error with one line and initials-never obliterate.
- A dispensing label needs drug name, concentration, dose, route, frequency, duration, quantity, expiration, storage, and warnings. Verify every calculation with the veterinarian before dispensing.
Worked example
A 12 kg dog is prescribed 5 mg/kg of an oral suspension at 50 mg/mL. Dose = 12 × 5 = 60 mg. Volume = 60 ÷ 50 = 1.2 mL. Dispense an oral syringe and demonstrate the 1.2 mL mark rather than allowing a kitchen spoon. Record the calculation and client instruction in the medical record.
Traps that cost marks
- Mixing mg/kg with mg/lb: 1 lb = 0.454 kg, so a 22 lb dog weighs 10 kg.
- Misreading percent solutions: 1% = 10 mg/mL, so 2% lidocaine = 20 mg/mL.
- Assuming every drug can be refrigerated; insulin and some vaccines require it, but other drugs precipitate.
- Skipping expiration and compatibility checks before dispensing.