Free North American Pharmacist Licensure Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the North American Pharmacist Licensure Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1A pharmacy student asks which molecular target warfarin acts on to produce anticoagulation. Which target does warfarin inhibit?

   1. A. The C1 subunit of the vitamin K epoxide reductase enzyme complex
   2. B. Activated factor X within the prothrombinase complex
   3. C. The platelet P2Y12 adenosine diphosphate receptor
   4. D. The active site of thrombin (activated factor II)

   Answer: A

   Explanation: The FDA-approved labeling for warfarin sodium states that "Warfarin acts by inhibiting the synthesis of vitamin K-dependent clotting factors, which include Factors II, VII, IX, and X, and the anticoagulant proteins C and S" and that "Warfarin is thought to interfere with clotting factor synthesis by inhibition of the C1 subunit of vitamin K epoxide reductase (VKORC1) enzyme complex". Inhibiting that reductase blocks regeneration of reduced vitamin K, so the gamma-carboxylation step needed to activate those factors cannot proceed. The other three options name the real targets of other anticoagulant and antiplatelet drug classes (direct factor Xa inhibitors, P2Y12 inhibitors, and direct thrombin inhibitors), none of which warfarin acts on.

   Reference: DailyMed - COUMADIN- warfarin sodium tablet — Section 12.1 Mechanism of Action

2. 2A child returns for the next dose in a vaccine series three days before the minimum interval has elapsed. How should the immunizing pharmacist treat a dose given at that visit?

   1. A. As a valid dose, because doses given 4 days or fewer before the minimum interval are counted as valid
   2. B. As an invalid dose that must be repeated after the full minimum interval has elapsed from it
   3. C. As a valid dose only if the series is being given on an accelerated schedule for imminent travel
   4. D. As a valid dose only if the patient is already past the minimum age for that dose of the series

   Answer: A

   Explanation: CDC best practice guidance states: "Known as the “grace period”, vaccine doses administered ≤4 days before the minimum interval or age are considered valid; however, local or state mandates might supersede this 4-day guideline" and that "Doses of any vaccine administered ≥5 days earlier than the minimum interval or age should not be counted as valid doses and should be repeated as age appropriate." A dose three days early therefore falls inside the grace period. Option B states the rule that applies from five days early onward; options C and D attach conditions that the grace period does not carry, and an accelerated schedule is a separate mechanism that still respects minimum intervals.

   Reference: Timing and Spacing of Immunobiologics | Vaccines & Immunizations | CDC — 'Spacing of multiple doses of the same antigen'

3. 3A patient returns for the third dose of a vaccine series that was started at the same pharmacy. How often should the patient be screened for contraindications and precautions?

   1. A. Before each dose of vaccine is administered
   2. B. Before the first dose of the series only, with later doses given on the original screening
   3. C. Before the first dose and again only if the patient reports a new medical condition
   4. D. Before the first dose and at least annually thereafter for patients on multi-year schedules

   Answer: A

   Explanation: CDC guidance states: "Persons who administer vaccines should screen patients for contraindications and precautions to the vaccine before each dose of vaccine is administered (Table 4-1). Screening is facilitated by consistent use of screening questionnaires, which are available from certain state vaccination programs and other sources". Per-dose screening matters because most contraindications are acquired rather than fixed; the same source notes that "the majority of contraindications are temporary", so a patient cleared at dose one may not be clear at dose three. Each of the other options would let an intervening event go undetected.

   Reference: Contraindications and Precautions | Vaccines & Immunizations | CDC — 'General Principles'

4. 4A patient taking a marketed drug develops a blood dyscrasia that is treated without admission to hospital. Under the postmarketing reporting regulation, does this event meet the definition of a serious adverse drug experience?

   1. A. Yes, because important medical events may be serious on medical judgement even without death, a life-threatening event or hospitalisation
   2. B. No, because the definition is closed and requires death, a life-threatening event, hospitalisation, disability or a congenital anomaly
   3. C. No, because blood dyscrasias are expressly excluded from the definition unless they are fatal
   4. D. Yes, because any haematologic adverse event is automatically serious irrespective of medical judgement

   Answer: A

   Explanation: The regulation defines the term as "Any adverse drug experience occurring at any dose that results in any of the following outcomes: Death, a life-threatening adverse drug experience, inpatient hospitalization or prolongation of existing hospitalization, a persistent or significant disability/incapacity, or a congenital anomaly/birth defect," and then extends it: "Important medical events that may not result in death, be life-threatening, or require hospitalization may be considered a serious adverse drug experience when, based upon appropriate medical judgment, they may jeopardize the patient or subject and may require medical or surgical intervention to prevent one of the outcomes listed in this definition." It names as examples "blood dyscrasias or convulsions that do not result in inpatient hospitalization". The judgement clause is what option B omits and option D removes.

   Reference: eCFR :: 21 CFR 314.80 -- Postmarketing reporting of adverse drug experiences. — 21 CFR 314.80(a), definition of serious adverse drug experience

5. 5A pharmacy is configuring its system to receive electronic prescriptions for controlled substances. Which schedules does the federal regulation governing that subpart cover?

   1. A. Schedules II, III, IV and V
   2. B. Schedules III, IV and V only
   3. C. Schedules II and III only
   4. D. Schedules I, II, III, IV and V

   Answer: A

   Explanation: The regulation states: "This subpart addresses the requirements that must be met to issue and process Schedule II, III, IV, and V controlled substance prescriptions electronically," and that "A practitioner may issue a prescription for a Schedule II, III, IV, or V controlled substance electronically if all of the following conditions are met". Schedule I is not included because those substances have no accepted medical use and are not dispensed on prescription, which is what makes option D wrong. Options B and C would exclude schedules the subpart expressly covers.

   Reference: eCFR :: 21 CFR 1311.100 -- General. — 21 CFR 1311.100(a) and (b)

6. 6A patient stops taking clopidogrel today. Because the active metabolite binds its receptor irreversibly, for approximately how long will the platelets already exposed to that metabolite remain affected?

   1. A. About 7 to 10 days
   2. B. About 24 to 48 hours
   3. C. About 3 to 5 days
   4. D. About 14 to 21 days

   Answer: A

   Explanation: The FDA-approved labeling for clopidogrel bisulfate explains that the drug is "an inhibitor of platelet activation and aggregation through the irreversible binding of its active metabolite to the P2Y 12 class of ADP receptors on platelets" and that "This action is irreversible. Consequently, platelets exposed to clopidogrel's active metabolite are affected for the remainder of their lifespan (about 7 to 10 days)." Because the bond cannot be reversed, recovery of platelet function depends on production of new platelets rather than on elimination of the drug, so the duration matches the platelet lifespan and not the plasma half-life implied by the shorter intervals offered.

   Reference: DailyMed - PLAVIX- clopidogrel tablet, film coated — Sections 12.1 Mechanism of Action and 12.2 Pharmacodynamics

7. 7A record review shows that the first and second doses of Haemophilus influenzae type b vaccine were given only 14 days apart, although the minimum interval is 4 weeks. What should be done?

   1. A. Repeat the second dose at least 4 weeks after the invalid dose and count the repeat as the valid second dose
   2. B. Repeat the second dose immediately and count the original dose as the valid second dose of the series
   3. C. Accept both doses as valid and shorten the interval before the third dose by the same 14 days
   4. D. Repeat the entire series from the first dose, observing the minimum interval between each dose

   Answer: A

   Explanation: The guidance works through this exact case: "For example, if the first and second doses of Haemophilus influenzae type b (Hib) were administered only 14 days apart, the second dose would be invalid and need to be repeated because the minimum interval from dose 1 to dose 2 is 4 weeks. The repeat dose should be administered ≥4 weeks after the invalid dose (in this case, the second). The repeat dose is counted as the valid second dose." Only the offending dose is repeated, and the clock runs from that invalid dose, not from the first dose, which is why options B, C and D each either preserve an invalid dose or discard valid ones.

   Reference: Timing and Spacing of Immunobiologics | Vaccines & Immunizations | CDC — 'Spacing of multiple doses of the same antigen'

8. 8A patient reports several drug and substance allergies before receiving a vaccine. What does CDC guidance direct the pharmacist to do with that history?

   1. A. Cross-check the allergens identified in the history against the allergens identified in the package inserts
   2. B. Refer the patient for skin testing with the vaccine before any dose is given
   3. C. Defer all vaccination until an allergist has documented that each reported allergy is IgE-mediated
   4. D. Administer the vaccine and observe for 60 minutes, since reported allergies rarely reflect true hypersensitivity

   Answer: A

   Explanation: CDC guidance states: "The best practice to prevent allergic reactions is to identify individuals at increased risk by obtaining a history of allergy to previous vaccinations and vaccine components that might indicate an underlying hypersensitivity," and that "Components of each vaccine are listed in the respective package insert ... The allergens identified in the history can be cross-checked against the allergens identified in package inserts." Skin testing with the vaccine is specifically not endorsed: "Other measures, such as dividing and administering the vaccine by a 2-step approach and skin testing with vaccine, are not recommended."

   Reference: Preventing and Managing Adverse Reactions | Vaccines & Immunizations | CDC — 'Preventing adverse reactions'

9. 9Under the National Childhood Vaccine Injury Act, how do the vaccine adverse event reporting requirements differ between manufacturers and health care personnel?

   1. A. Manufacturers must report all adverse events occurring after vaccination, while health care providers must report the events that appear in the reportable events table
   2. B. Manufacturers and health care providers must both report every adverse event occurring after vaccination, without regard to the reportable events table
   3. C. Manufacturers must report only the events appearing in the reportable events table, while health care providers must report all adverse events they observe
   4. D. Manufacturers must report all adverse events occurring after vaccination, while health care providers report only those they judge to be causally related

   Answer: A

   Explanation: CDC guidance states: "The National Childhood Vaccine Injury Act of 1986 requires health care personnel and vaccine manufacturers to report to VAERS specific adverse events that occur after vaccination. The reporting requirements are different for manufacturers and health care personnel. Manufacturers are required to report all adverse events that occur after vaccination to VAERS, whereas health-care providers are required to report events that appear in the reportable events table on the VAERS website." Option D misstates the provider standard, since the guidance encourages reporting "even if they are uncertain that the adverse event is related causally to vaccination."

   Reference: Preventing and Managing Adverse Reactions | Vaccines & Immunizations | CDC — 'Reporting adverse events after vaccination'

10. 10A pharmacy is writing its records retention policy for controlled substance inventories and records. For how long must those records be kept and available for inspection?

    1. A. At least 2 years from the date of the inventory or record
    2. B. At least 1 year from the date of the inventory or record
    3. C. At least 5 years from the date of the inventory or record
    4. D. At least 7 years from the date of the inventory or record

    Answer: A

    Explanation: The regulation provides: "Except as provided in paragraphs (a)(1) and (2) of this section, every inventory and other record required to be kept under this part must be kept by the registrant and be available for inspection and copying by authorized employees of the Administration, for at least 2 years from the date of such inventory or record." Two obligations run together, retention and availability for inspection. The other periods offered are real retention requirements in other regulatory contexts, which is why a policy written from general practice rather than from this provision can land on the wrong figure.

    Reference: eCFR :: 21 CFR 1304.04 -- Maintenance of records and inventories. — 21 CFR 1304.04(a)