Mesothelioma Chemotherapy with Carboplatin
Carboplatin, also known by the brand name Paraplatin, is a member of the same drug class as cisplatin, and works in the same way.
How is the Mesothelioma Chemotherapy Drug Carboplatin Different from Cisplatin?
Carboplatin is similar to cisplatin in that it causes interstrand DNA cross-links (see cisplatin). However, the aquation of carboplatin happens at a slower rate than in cisplatin. Aquation is a chemical process where water molecules become part of the drug by displacing either one or both of the chlorines it contains. Aquation activates the drug. The difference between aquation rates is the reason that higher concentrations of carboplatin are needed to produce the same levels of DNA binding as cisplatin. However, when concentration levels of the drugs that produce equivalent levels of DNA binding are compared, both mesothelioma chemotherapy drugs create the same number of cross-links.
In an article titled “Review of the Comparative Pharmacology and Clinical Activity of Cisplatin and Carboplatin” published January 1999 in the Journal of Clinical Oncology, researchers noted these additional differences:
- The half-life (the period of time it takes the drug to reduce by half) of cisplatin is 43 minutes with approximately 1/4th being eliminated within the first 24 hours. The half-life of carboplatin is 116 minutes. This means carboplatin stays in the body longer.
- The side effects of nausea and vomiting are experienced by nearly 100 percent of all patients treated with cisplatin, but by only 35 percent of those receiving carboplatin.
- Carboplatin, except at very high doses, causes very little if any kidney damage.
- In 85 percent of all patients receiving a dose over 300 mg/m2 of cisplatin, side effects can include hearing loss, numbness, tingling, and burning sensations in the arms and legs, nerve damage to the heart, stomach, intestines, bladder or genitals, seizures, and changes in brain function. In nearly half, the damage is irreversible. In carboplatin, the incidence of these side effects is less than 5 percent.
The authors of this article also added that as a result of their analysis of 23 trials comparing the two drugs, they concluded that, “Carboplatin can also be substituted for cisplatin in the treatment of non–small-cell and extensive-stage small-cell lung cancers.”
What is the Most Significant Side Effect of Mesothelioma Chemotherapy Drug Carboplatin?
The most troubling side effect of carboplatin is myelosuppression, or suppression of bone marrow function. This usually results in a significant decrease in blood cell and platelet production. The lowest production levels usually happen between 21 to 28 days after beginning treatment; after that time, blood cell and platelet levels become more stable. They may even return to their levels before treatment began.
The decrease in white cell count can cause increase risk of infection, meaning possible hospital admission and/or the need for treatment with antibiotics. The decrease in red blood cell count can lead to anemia.