In 2008, the United States Food and Drug Administration approved a combination of pemetrexed and cisplatin as a treatment for non-squamous, non-small cell lung cancers. While pemetrexed and cisplatin had been used individually for years prior as chemotherapeutic agents, cisplatin had previously been used predominantly in the treatment of advanced bladder cancer and metasticizing gonadal tumors. Like other platinum-containing compound drugs, cisplatin could still be used in the treatment of a diverse array of other cancers. Pemetrexed, while always prescribed alongside another chemotherapeutic agent, had however always been considered to be a specific for malignant pleural mesothelioma and other non-small cell lung cancers. During a phase III clinical trial, the finding that a combination of permetrexed and cisplatin was superior to and produced less hematological toxicity than a combination of gemcitabine HCl and cisplatin in patients with non-squamous cancer cell histology resulted in the combination becoming a standard treatment for these cancers. While this may prove to be a significant development in cancer research, these administration of these two drugs carries considerable risk.
The side-effects of pemetrexed and cisplatin can be quite severe, including vomiting, constipation, pharyngitis, stomatitis, anemia, lowered immunity and decreased red and white blood cell count. These side-effects may occur in as many as one in every five patients using the combination drug. Other common side-effects include dizziness and confusion, weakness and fatigue, mood alteration and depression, or even joint and muscle pain.
The risks of pemetrexed and cisplatin treatment are not inconsiderable. It is important that patients are monitored for itching, rash or labored breathing, all signs of a potentially fatal anaphylactic reaction to the drugs. Some patients develop tinnitus — ringing and other sounds in the ears, loss of high frequency hearing, decreased hearing acuity, or even deafness as a result of cisplatin's ototoxicity. The risk of developing hearing loss is considerably higher among young children receiving the drug. Additionally, due to the hematological toxicity of the combination drug, some patients may require blood transfusions as a result of treatment.
Risks like dangerous drug interactions can be more easily managed. While the comprehensive list of pemetrexed and cisplatin drug interactions is quite long and includes diverse pharmaceutical classes, only a few are commonly used medications. Over-the-counter medications in the non-steroidal anti-inflammatory (NSAID) class of drugs can dramatically interfere with clotting in patients undergoing chemotherapy. This includes common painkillers like ibuprofen and naproxen. For this reason, it is important to consult closely with a doctor before using any medication while undergoing treatment with pemetrexed and cisplatin.