NAVLE Veterinary Pharmacy, Prescribing Law & Medicines Regulation: practice questions

1 · Prescription writing · hard

A label reads 'Apply 1 drop OD'. The owner of a dog with an ulcer in the right eye puts one drop in the left eye once a day, reading OD as 'once daily'. What is the best prescribing practice to prevent this?

1. Keep the abbreviation and explain it verbally at collection
2. Use OD only for once daily and OS for every other day
3. Write OU so that both eyes are covered whichever is meant
4. Write the eye and the frequency in plain words, such as right eye once a day

2 · Dispensing · easy

An owner asks whether she can crush an enteric-coated tablet to hide it in food for her dog. What is the correct advice?

1. Yes, provided the powder is mixed into a fatty food
2. No, but it may be split into quarters without any loss of effect
3. Yes; all tablets work the same once they have been crushed
4. No; crushing defeats the protective enteric coating

3 · Dispensing · medium

A multi-dose injectable vial was first broached 35 days ago. Its SPC gives an in-use shelf life of 28 days. Half the liquid remains and the printed expiry date is next year. What should be done?

1. Refrigerate it to reset the in-use shelf life for another 28 days
2. Use it, because the printed expiry date has not yet been reached
3. Use it for non-urgent cases only, until the printed expiry date
4. Discard it; the in-use shelf life has ended

4 · Dispensing · medium

A horse is euthanased with an overdose of pentobarbital on a farm. Why must the carcass be disposed of securely and not left for scavengers?

1. Leaving it exposed lets pentobarbital leach out and reach a safe level
2. Pentobarbital residues in the carcass can kill dogs and wild scavengers that eat it
3. Pentobarbital residues make the meat safe to eat but illegal to sell
4. The drug breaks down into a gas that harms people near the carcass

5 · Dispensing · easy

How many milligrams of drug are there in 1 mL of a 2% w/v solution?

1. 2 mg
2. 0.2 mg
3. 200 mg
4. 20 mg

6 · Dispensing · easy

5 g of a drug is dissolved and made up to 250 mL. What is the strength as % w/v?

1. 0.2%
2. 2%
3. 20%
4. 5%

7 · Withdrawal periods · medium

A vet gives a calf double the labelled dose of an antibiotic. Why is the label withdrawal period no longer reliable?

1. Withdrawal depends only on the route of administration, never on the dose
2. A higher dose speeds up elimination, so the label withdrawal becomes too long
3. More drug must be cleared, so residues could exceed the MRL at label time
4. Labels always build in a margin for a doubled dose, so nothing changes at all

8 · Withdrawal periods · medium

In the United States, how does a vet set the withdrawal time after extra-label use in a food animal?

1. By setting a substantially extended withdrawal based on scientific data
2. By applying a fixed 28-day meat and 7-day milk minimum
3. By multiplying the label withdrawal by 1.5, as fixed in federal law
4. By using the label time for the nearest approved species

9 · Pharmacovigilance and adverse-event reporting · easy

A farmer reports that a wormer, given correctly, no longer reduces faecal egg counts in his sheep. Is this a reportable adverse event?

1. No; poor efficacy is a commercial matter for the seller
2. Only if a sheep dies after treatment with the wormer
3. Yes; lack of expected efficacy is reportable
4. No; only reactions in the treated animals are reported

10 · Record keeping · easy

For how long must US records of extra-label drug use in animals be kept under 21 CFR Part 530?

1. 10 years
2. 6 months
3. 5 years
4. 2 years