Cisplatin is a platinum-based chemotherapy drug used to treat various cancers, including those of the bladder, ovary, testicles, and lung. The drug works by interfering with cancer cell DNA, ultimately triggering cell death. While traditionally given in high doses every three to four weeks, an alternative regimen uses lower, more frequent “weekly” administrations. This weekly schedule aims to improve tolerability and reduce the intensity of immediate side effects. Despite this, cisplatin remains a potent drug with predictable side effects, which occur because the drug affects rapidly dividing healthy cells in addition to cancer cells.
Renal Toxicity and Hydration Needs
The kidneys are susceptible to damage from cisplatin, known as nephrotoxicity, which is a concern even with weekly dosing. The drug is eliminated predominantly through the kidneys, accumulating in the proximal tubular epithelial cells. This accumulation can lead to acute kidney injury in 20% to 30% of patients after a single dose.
Aggressive hydration protocols are the most important measure for preventing this toxicity. This involves intravenous saline solution flushing before and after the infusion to dilute the drug and promote rapid excretion, reducing contact time with kidney tissue. Patients are monitored with mandatory blood tests, including Blood Urea Nitrogen (BUN), creatinine, and Glomerular Filtration Rate (GFR), to track kidney function.
If monitoring reveals a significant decline in kidney function, the treatment plan may require adjustment. Continued use despite rising toxicity can lead to progressive and permanent kidney damage. Clinicians may need to adjust the cisplatin dose or discontinue the drug entirely to prevent long-term renal impairment. Cisplatin also causes electrolyte disturbances, notably magnesium loss, which requires supplementation and can further predispose the kidney to damage.
Sensory System Damage: Hearing Loss and Neuropathy
Cisplatin causes damage to the sensory system, leading to cumulative issues with hearing and nerve function. Ototoxicity, or hearing damage, can manifest as tinnitus (ringing in the ears) or permanent hearing loss. This loss typically affects high-frequency sounds, making it difficult to distinguish speech in noisy environments.
The damage results from irreversible cell death in the outer hair cells of the cochlea. Because this toxicity is cumulative, the risk of severe hearing loss increases significantly with a higher total lifetime dose of cisplatin. Baseline audiograms are often performed before treatment to establish a reference point and monitor for changes.
Peripheral neuropathy is another sensory side effect, characterized by numbness, tingling, burning, or pain in the hands and feet. This condition occurs because cisplatin accumulates in the dorsal root ganglia and peripheral nerves. The severity of this neuropathy is strongly linked to the total cumulative dose received. These neurological symptoms may persist or worsen for several weeks or months after the final dose of chemotherapy.
Gastrointestinal Distress and Blood Count Suppression
Gastrointestinal distress is an immediate and common side effect of weekly cisplatin. Nausea and vomiting are dose-related and can be severe, sometimes persisting for up to a week after administration. Cisplatin is classified as highly emetogenic, meaning it carries a high risk of causing vomiting linked to the release of serotonin metabolites.
Prophylactic antiemetic therapy is standard practice, involving medications given before the infusion to prevent symptoms. This typically includes a combination of drugs, such as serotonin antagonists and corticosteroids, to manage both acute and delayed symptoms. Other common gastrointestinal issues include appetite loss, diarrhea, and occasionally hiccups. Consistent use of prescribed anti-nausea medications is important for maintaining nutrition and quality of life.
Cisplatin also causes myelosuppression, the suppression of bone marrow activity, leading to reduced blood cell counts. This results in low white blood cells (neutropenia), low red blood cells (anemia), and low platelet counts (thrombocytopenia). The drop in white blood cells increases the risk of infection because the immune defense is weakened.
Anemia commonly causes fatigue, weakness, and shortness of breath due to decreased oxygen transport. Cisplatin often has a disproportionate effect on red blood cell production, leading to cumulative anemia. Weekly blood count monitoring is necessary to determine if a patient needs transfusions or growth factor injections.
Monitoring Protocols and Urgent Warning Signs
Patients undergoing weekly cisplatin must adhere to monitoring protocols to catch potential complications early. Blood tests are scheduled before each weekly treatment to evaluate kidney function, liver enzymes, and complete blood counts. This ensures the patient is safe to receive the next dose, and any significant change may prompt the oncology team to hold or adjust the treatment.
Beyond scheduled monitoring, patients and caregivers must be aware of urgent warning signs requiring immediate medical attention. A fever above 100.4°F (38°C) is a serious concern, as it signals a potential life-threatening infection due to neutropenia.
Urgent Warning Signs
- Signs of severe infection, such as chills, sore throat, or a burning sensation during urination.
- Severe kidney distress, including a significant decrease in urine output or inability to urinate.
- Signs of hemorrhage, such as unexplained bruising, bleeding gums, or black, tarry stools, indicating severely low platelet counts.
- Sudden, severe confusion or shortness of breath.
- Symptoms of an allergic reaction, like swelling of the face or difficulty breathing.