DOSAGE CALCULATION RN MENTAL HEALTH 3.0
2026/2027 Actual Exam – Complete Questions & Detailed
Rationales – Pass Guaranteed – A+ Graded
TABLE OF CONTENTS
Section 1 | Basic Dosage Calculations | Q1 – Q10
Section 2 | Oral & Injectable Medications | Q11 – Q20
Section 3 | IV Flow Rates & Infusion Time | Q21 – Q30
Section 4 | Weight-Based & Pediatric Calculations | Q31 – Q40
Section 5 | Psychiatric Medication Dosages & Safety | Q41 – Q50
Instructions: Choose the single best answer. Pass: 40 in 90 minutes.
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SECTION 1: BASIC DOSAGE CALCULATIONS Q1 – Q10
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Question 1 of 50
A 34-year-old patient admitted to the psychiatric unit has an order for haloperidol 5 mg
IM for acute agitation. The unit dose syringe is labeled 2 mg/mL. How many mL will the
nurse administer?
A. 0.4 mL
B. 1.5 mL
C. 2.5 mL ✓ CORRECT
D. 5.0 mL
Correct Answer: C
Rationale: 5 mg divided by 2 mg per mL equals 2.5 mL, which is the correct volume to
administer. 0.4 mL would result from inverting the calculation, and 5 mL would be a
,tenfold overdose. Always double-check high-alert antipsychotic doses with a second
nurse when possible.
Question 2 of 50
A 28-year-old patient on the mood disorder unit has a PRN order for lorazepam 0.5 mg
PO for anxiety. The pharmacy sends 1 mg scored tablets. How many tablets should the
nurse give?
A. 0.25 tablet
B. 0.5 tablet ✓ CORRECT
C. 1 tablet
D. 2 tablets
Correct Answer: B
Rationale: One-half of a 1 mg scored tablet delivers the ordered 0.5 mg dose accurately.
Giving a whole tablet would double the ordered dose and increase sedation risk, while
quartering a tablet beyond the score line is not accurate. Scored tablets should only be
split along the scored line.
Question 3 of 50
A 56-year-old patient on the geriatric psychiatry unit is prescribed trazodone 100 mg PO
at bedtime for sleep. The medication cart contains 50 mg tablets. How many tablets
will the nurse administer?
A. 1 tablet
B. 2 tablets ✓ CORRECT
C. 3 tablets
D. 5 tablets
Correct Answer: B
Rationale: Two 50 mg tablets equal the ordered 100 mg dose. One tablet would
underdose the patient, and three tablets would exceed the order by 50 mg. Trazodone is
, frequently used in geriatric psychiatry, so accurate tablet counts prevent oversedation
and fall risk.
Question 4 of 50
A 42-year-old patient with bipolar disorder is ordered quetiapine 200 mg PO for bedtime.
The pharmacy supplies 100 mg tablets. How many tablets should the nurse administer?
A. 0.5 tablet
B. 1 tablet
C. 1.5 tablets
D. 2 tablets ✓ CORRECT
Correct Answer: D
Rationale: Two 100 mg tablets provide the exact 200 mg ordered dose. One tablet
would be subtherapeutic for this patient, and 1.5 tablets would require splitting
unscored tablets which is unsafe. Seroquel is commonly titrated in bipolar disorder, so
verifying the tablet strength against the order is essential.
Question 5 of 50
A 67-year-old patient with schizophrenia is prescribed risperidone 1 mg PO twice daily.
The pharmacy sends 0.5 mg tablets. How many tablets per dose?
A. 1 tablet
B. 2 tablets ✓ CORRECT
C. 3 tablets
D. 4 tablets
Correct Answer: B
Rationale: Two 0.5 mg tablets equal the ordered 1 mg per dose. Four tablets would
deliver 2 mg, which is double the ordered amount and could cause extrapyramidal
symptoms. Risperidone is a high-alert medication in geriatric psychiatry due to
orthostatic hypotension and fall risk.
2026/2027 Actual Exam – Complete Questions & Detailed
Rationales – Pass Guaranteed – A+ Graded
TABLE OF CONTENTS
Section 1 | Basic Dosage Calculations | Q1 – Q10
Section 2 | Oral & Injectable Medications | Q11 – Q20
Section 3 | IV Flow Rates & Infusion Time | Q21 – Q30
Section 4 | Weight-Based & Pediatric Calculations | Q31 – Q40
Section 5 | Psychiatric Medication Dosages & Safety | Q41 – Q50
Instructions: Choose the single best answer. Pass: 40 in 90 minutes.
══════════════════════════════════════
SECTION 1: BASIC DOSAGE CALCULATIONS Q1 – Q10
══════════════════════════════════════
Question 1 of 50
A 34-year-old patient admitted to the psychiatric unit has an order for haloperidol 5 mg
IM for acute agitation. The unit dose syringe is labeled 2 mg/mL. How many mL will the
nurse administer?
A. 0.4 mL
B. 1.5 mL
C. 2.5 mL ✓ CORRECT
D. 5.0 mL
Correct Answer: C
Rationale: 5 mg divided by 2 mg per mL equals 2.5 mL, which is the correct volume to
administer. 0.4 mL would result from inverting the calculation, and 5 mL would be a
,tenfold overdose. Always double-check high-alert antipsychotic doses with a second
nurse when possible.
Question 2 of 50
A 28-year-old patient on the mood disorder unit has a PRN order for lorazepam 0.5 mg
PO for anxiety. The pharmacy sends 1 mg scored tablets. How many tablets should the
nurse give?
A. 0.25 tablet
B. 0.5 tablet ✓ CORRECT
C. 1 tablet
D. 2 tablets
Correct Answer: B
Rationale: One-half of a 1 mg scored tablet delivers the ordered 0.5 mg dose accurately.
Giving a whole tablet would double the ordered dose and increase sedation risk, while
quartering a tablet beyond the score line is not accurate. Scored tablets should only be
split along the scored line.
Question 3 of 50
A 56-year-old patient on the geriatric psychiatry unit is prescribed trazodone 100 mg PO
at bedtime for sleep. The medication cart contains 50 mg tablets. How many tablets
will the nurse administer?
A. 1 tablet
B. 2 tablets ✓ CORRECT
C. 3 tablets
D. 5 tablets
Correct Answer: B
Rationale: Two 50 mg tablets equal the ordered 100 mg dose. One tablet would
underdose the patient, and three tablets would exceed the order by 50 mg. Trazodone is
, frequently used in geriatric psychiatry, so accurate tablet counts prevent oversedation
and fall risk.
Question 4 of 50
A 42-year-old patient with bipolar disorder is ordered quetiapine 200 mg PO for bedtime.
The pharmacy supplies 100 mg tablets. How many tablets should the nurse administer?
A. 0.5 tablet
B. 1 tablet
C. 1.5 tablets
D. 2 tablets ✓ CORRECT
Correct Answer: D
Rationale: Two 100 mg tablets provide the exact 200 mg ordered dose. One tablet
would be subtherapeutic for this patient, and 1.5 tablets would require splitting
unscored tablets which is unsafe. Seroquel is commonly titrated in bipolar disorder, so
verifying the tablet strength against the order is essential.
Question 5 of 50
A 67-year-old patient with schizophrenia is prescribed risperidone 1 mg PO twice daily.
The pharmacy sends 0.5 mg tablets. How many tablets per dose?
A. 1 tablet
B. 2 tablets ✓ CORRECT
C. 3 tablets
D. 4 tablets
Correct Answer: B
Rationale: Two 0.5 mg tablets equal the ordered 1 mg per dose. Four tablets would
deliver 2 mg, which is double the ordered amount and could cause extrapyramidal
symptoms. Risperidone is a high-alert medication in geriatric psychiatry due to
orthostatic hypotension and fall risk.
