Case Study 8

For each question, choose the answer you think is correct. See the end of this page for the answers.

A.C. is a 53-year-old male diagnosed with malignant mesothelioma, scheduled to be treated with LUMMPG. As per the protocol, his oncologist prescribes CISplatin on Day 1 and gemcitabine on Days 1 and 8.

Weight: 82 kg Height: 174 cm

Lab results taken 72 hours prior to first treatment:

WBC 8.6
ANC 3.5
Platelets 257
Creatinine 130
Bilirubin 10
Alk Phos 63
AST 19
LDH 123

1. Which of the following doses of CISplatin and gemcitabine should the oncologist prescribe?

149 mg CISplatin and 2488 mg gemcitabine
89 mg CISplatin and 1493 mg gemcitabine
90 mg CISplatin and 2488 mg gemcitabine
150 mg CISplatin and 1500 mg gemcitabine

2. Which of the following measures are used in LUMMPG to prevent CISplatin-related nephrotoxicity?

1000 mL NS IV over 60 minutes is given as pre-hydration to prevent nephrotoxicity from CISplatin accumulation in the kidneys; oral hydration is also encouraged
Mannitol is used to alkalinize the urine and prevent nephrotoxicity from CISplatin precipitation in acidic urine
Mannitol is used as forced diuresis to increase urine flow and prevent nephrotoxicity due to CISplatin accumulation in the kidneys
1 and 2
1 and 3

Answer 1

The correct answer is 1.

Rationale:

BSA calculation

Creatinine clearance =

N x (140 – age) x weight (kg)
Serum creatinine (micromole/L) N = 1.23 for males

= 1.23 x (140 – 53) x 82
130

= 67.5 mL/min

CISplatin dose calculation = 75 mg/m² x 1.99 m² = 149 mg. According to the current LUMMPG protocol, there is no need to reduce the CISplatin dose for creatinine clearance greater than or equal to 60 mL/min.

Gemcitabine dose calculation

= 1250 mg/m² x 1.99 m²

= 2488 mg

Answer 2

The correct answer is 5.

Rationale:

The LUMMPG protocol "Treatment" section lists the pre-hydration, mannitol forced diuresis and also KCl and MgSO₄ supplementation used supportively in this protocol. The protocol "Precautions" section states that nephrotoxicity is common with CISplatin and encourages oral hydration.

As described in Hydration [Clinical Pharmacy Guide - Module 5 - Supportive Care (PDF)], both hydration (IV and oral) and forced diuresis using mannitol are important preventative measures for CISplatin-related nephrotoxicity.