Chemotherapy-induced toxicities are common and serious clinical problems that adversely impact both the quality of life of cancer patients and the ability of patients to continue treatment for their cancer. Very little has been accomplished to prevent or reduce chemotherapy-induced toxicities such as nerve damage (neurotoxicity), kidney damage (nephrotoxicity), and hearing impairment (ototoxicity).
Paclitaxel (frequently sold under the brand names Taxol and Onxol) is a widely used chemotherapeutic agent for cancers of the lung, breast, ovary, esophagus and other types of cancer and it has been a generic drug for the last three or so years. Paclitaxel is known as a taxane type of chemotherapy drug.
Docetaxel is another widely used taxane drug (sold under the name Taxotere) that is used in the treatment of cancers of the lung, breast, ovary and other common cancers. Despite the broad antitumor activity of taxanes, their clinical usefulness has been limited by common side effects such as painful nerve damage (neurotoxicity), reduction of white blood cell counts, liver damage, allergic reactions, nausea and vomiting, and other toxicities. For example, it is estimated that over 50% of patients receiving paclitaxel experience some form of drug-induced nerve damage.
While medications designed to prevent or treat nausea, vomiting and decreased white blood cell counts are available, there are currently no treatments for other serious taxane-induced side effects, particularly nerve damage. Platinum drugs, such as cisplatin and carboplatin can cause significant side effects, including nerve damage (neurotoxicity), nausea, vomiting, and bone marrow dysfunction.
Nerve damage has been reported for all doses and administration schedules of platinum drugs, but no effective therapies are available for the prevention or treatment of platinum drug-induced nerve damage. There is a drug, Tavocept, that is aimed at preventing or reducing common and serious side effects, particularly nerve and kidney damage, associated with taxane and platinum drugs.
My wife was inflicted with leukoencephalopathy (a form of diffuse white matter injury that can follow taxol chemotherapy), confirmed by an unenhanced/enhanced MRI. Leukoencephalopathy syndrome is a disorder that results from structural alterations of cerebral white matter, is characterized by cerebral edema, and can occur in patients of any age. A diagnosis must confirm exposure to a toxin and the presence of neurobehavioral deficits and neuroradiologic abnormalities.
Leukoencephalopathy is a structural alteration of cerebral white matter. You simply do not give another drug and it goes away. At best, cognitive rehabilitation on an outpatient level is about all one can hope for. For older women, the impact of chemotherapy may be compounded by the natural aging process (she was 65). At the time, we tried exploring with Ritalin. Another drug that can be explored is Procrit. However, after further complications happen (radiation necrosis), we were not able to find if Ritalin was effective.
Also, Cremophor is a toxic solvent used to deliver taxol. It causes severe allergic reactions, like nausea, vomiting, joint pain, appetite loss, brittle hair and tingling sensations in hands and feet. To avoid those reactions, patients are given steroids before receiving taxol, but steroids have their own side effects. Cremophor requires special intravenous tubes for delivering because it can leach the plastic off normal tubes.
There are a number of theories as to why this infliction happens. One is that some types of chemotherapy can cross the blood/brain barrier. Another is that the problem is created by free radicals, the toxic elements that many types of chemotherapy produce. And yet another is that some people have a genetic predisposition that makes them more susceptible to the effects of chemotherapy.