To determine whether the patient is planning to take the correct amount of ondansetron oral solution (Ondansetron) prior to chemotherapy

QUESTION

CLINICAL JUDGMENT 8-1 The patient tells the home care nurse that he has been given ondansetron oral solution to take 30 minutes prior to his chemotherapy appointments. He tells the nurse that he plans to take 2 Tbs of the ondansetron solution. Is the patient planning to take the correct amount of medication? Provide a rationale for your answer. Electronic Medical Record Provider Orders X USUAL DOSAGE: NDC 0054-0064-47 50 mL See Package Insert for Complete Prescribing Name D. Patient Age 79 Gender M DOB 11-08-xx Ondansetron Information. Oral Solution USP MR # 79014 Allergies NKDA Room 25-A Store at 20 to 25 C (68 to 77.F). 4 mg/5 mL [See USP Controlled Provider T. Physician, MD Date 11-05-Xx Room Temperature.] Each 5 mL contains Protect from light. 5 mg ondansetron Order hydrochloride USP, Store bottle upright dihydrate equivalent to in carton. 4 mg ondansetron (base). Ondansetron oral solution 24 mg PO 30 min prior to chemotherapy. Px only Distribu: West-Ward Pharmaceuticals Corp. Eatontown, NJ 07724 W WEST-WARD A HIKMA COMPANY In summary, the nurse can use the formula – H x @ = x to solve many dosage calculation problems encountered in the clinical area. The information on the drug label (the dosage strength) and the ordered medication are used to set up the formula for a dosage calculation. The same steps are used to solve the formula: check the units of measurement, convert if necessary so that the units in the fraction are the same and the units in the Q and the unknown are the same, cancel the units, and solve for the x (the unknown)

ANSWER

To determine whether the patient is planning to take the correct amount of ondansetron oral solution (Ondansetron) prior to chemotherapy, we need to perform a dosage calculation using the information provided on the drug label and the physician’s order.

Drug Label Information

Ondansetron oral solution concentration: 4 mg/5 mL
Physician’s order: 24 mg PO 30 minutes prior to chemotherapy

Calculation

We can use the formula: H x @ = x, where H represents the dose on hand (4 mg/5 mL), @ represents the desired dose (24 mg), and x represents the unknown quantity to be administered (mL of Ondansetron).

Setting up the formula:
H = 4 mg/5 mL
@ = 24 mg
x = ? mL

Now, let’s solve the equation:

(4 mg/5 mL) x = 24 mg

To isolate x, we can rearrange the equation:

x = (24 mg) / (4 mg/5 mL)

Now, perform the calculation:

x = (24 mg) / (4 mg/5 mL)

x = (24 mg) / (4 mg) x (5 mL)

x = (24 mg / 4 mg) x 5 mL

x = 6 x 5 mL

x = 30 mL

Answer: The patient should take 30 mL of the ondansetron oral solution, not 2 tablespoons (Tbs). Therefore, the patient is not planning to take the correct amount of medication.

Rationale

The physician’s order clearly specifies that the patient should take 24 mg of ondansetron 30 minutes prior to chemotherapy.
The concentration of the ondansetron oral solution is 4 mg/5 mL.
By performing the dosage calculation, we determined that the patient should take 30 mL of the solution to achieve the prescribed dose of 24 mg.
Taking only 2 tablespoons (Tbs) would likely result in an insufficient dose of the medication, potentially leading to inadequate nausea and vomiting control during chemotherapy.

It’s crucial for the patient to follow the prescribed dose accurately to ensure the effectiveness of the medication in managing chemotherapy-induced nausea and vomiting. The nurse should educate the patient on the correct dosage and administration method to prevent any dosing errors.