PEBC Treatment Planning 4

Question 1

A patient taking phenytoin for seizures is prescribed fluconazole for a fungal infection. What is the expected pharmacokinetic outcome?

Accepted Answer

Fluconazole inhibits CYP2C9, increasing phenytoin levels and toxicity risk

Answer

Fluconazole is a potent CYP2C9 inhibitor; since phenytoin is primarily metabolized by CYP2C9, co-administration can lead to significantly elevated phenytoin levels and toxicity.

Question 2

A child with otitis media has a penicillin allergy documented as 'hives and swelling.' What antibiotic is the most appropriate alternative?

Accepted Answer

Azithromycin, to avoid all beta-lactams due to severe allergy history

Answer

Hives and swelling suggest a possible IgE-mediated reaction; avoiding all beta-lactams and choosing azithromycin is the safest approach in this clinical context.

Question 3

A patient is prescribed methotrexate for rheumatoid arthritis. What supplement should ALWAYS be co-prescribed to reduce toxicity?

Accepted Answer

Folic acid 1–5 mg daily

Answer

Folic acid supplementation significantly reduces methotrexate-associated adverse effects such as mucositis, nausea, and hepatotoxicity without diminishing its therapeutic efficacy.

Question 4

When selecting an antibiotic for a urinary tract infection (UTI) in a patient with a sulfonamide allergy, which commonly used UTI agent must be avoided?

Accepted Answer

Trimethoprim-sulfamethoxazole (TMP-SMX)

Answer

TMP-SMX contains sulfamethoxazole, a sulfonamide antibiotic, and must be avoided in patients with documented sulfonamide allergy.

Question 5

A patient newly diagnosed with type 2 diabetes has an A1C of 9.5% and is otherwise healthy. According to Canadian Diabetes Association guidelines, what is the preferred initial pharmacotherapy?

Accepted Answer

Metformin plus a second agent due to high A1C unlikely to be controlled with monotherapy

Answer

Canadian guidelines recommend combination therapy at diagnosis when A1C is ≥1.5% above target, as monotherapy is unlikely to achieve glycemic goals in this scenario.

PEBC - Pharmacy Examining Board of Canada Practice Test

PEBC - Pharmacy Examining Board of Canada Practice Test

PEBC Treatment Planning 4