Pharmacological properties of the drug Cisplatin
Antitumor agent, platinum compound. The mechanism of action is probably due to the binding of cisplatin to cell DNA with the formation of intra- and interhelical cross-links, which change the structure and suppress DNA synthesis. To a lesser extent, cisplatin inhibits protein and RNA synthesis. Cisplatin does not have phase specificity. After intravenous administration, the pharmacokinetic parameters of cisplatin are described by a two-phase pharmacokinetic model. The initial phase is rapid, with a half-life of 29–45 minutes, followed by a long phase with a half-life of 2–4 days. This duration of the elimination phase is likely due to the high degree of protein binding. Typically, more than 90% of cisplatin is bound to plasma proteins, but with slow IV administration this figure may be higher. It is excreted mainly in the urine. About 15–25% of the dose is excreted quickly, mainly as unchanged substance in the first 2–4 hours and 20–75% in the first 24 hours. The remaining amount binds to tissues and blood plasma proteins. Cisplatin appears to accumulate in the kidneys, liver, small intestine and testes. It does not penetrate the BBB and is not detected in the CSF in significant quantities. Its level in the CSF is low, although significant amounts can be detected in brain tumors.
What to do if the tumor cannot be removed surgically?
If you are healthy enough to have major surgery, but the tumor is so widespread that surgery will not be successful, you have other treatment options.
- Chemoradiation therapy as an attempt to cure cancer. It is also called radical chemoradiotherapy.
Chemotherapy regimens recommended for radical chemoradiotherapy
Preferred Modes | Fluorouracil and oxaliplatin |
Fluorouracil and cisplatin | |
Fluoropyrimidines (fluorouracil or capecitabine) and paclitaxel |
- Systemic chemotherapy (see “Metastatic gastric cancer”).
Use of the drug Cisplatin
When used as monotherapy in children and adults, the doses and schedule of administration are as follows: 50–100 mg/m2 body surface as a single infusion over 6–8 hours every 3–4 weeks; IV or slow infusion of 15–20 mg/m2 daily for 5 days every 3–4 weeks. The dose should be reduced in patients with depressed bone marrow function. Repeated courses of cisplatin administration should not be started until:
- a) the level of creatinine in the blood serum will not decrease to 140 µmol/l; the level of urea in the blood plasma will not decrease to 9 mmol/l.
- b) the number of formed elements in the peripheral blood will not reach an acceptable level (platelets more than 100,000 per 1 mm3, leukocytes - more than 4000 per 1 mm3).
A basal audiogram should be performed and patients should be periodically assessed to determine hearing acuity. Patients should be adequately hydrated before and for 24 hours after cisplatin administration to ensure adequate diuresis and reduce nephrotoxicity. Hydration can be achieved by intravenous infusion of 2 liters of 5% glucose solution with the addition of 1/2–1/3 volume of 0.9% sodium chloride solution over 2–4 hours. The required amount of cisplatin for injection should be added to 1 liter of 0.9% sodium chloride solution and pour in for the required time. It is important to maintain adequate hydration and diuresis for 24 hours after cisplatin infusion. This can be achieved by administering 1–2 liters of 0.9% sodium chloride solution or a mixture of glucose and 0.9% sodium chloride solution for 6–12 hours. Cisplatin is usually used in combination therapy with the following cytotoxic drugs: in the treatment testicular cancer - vinblastine, bleomycin, actinomycin; in the treatment of ovarian cancer - cyclophosphamide, doxorubicin, hexamethylmelamine, fluorouracil; in the treatment of head and neck cancer - bleomycin and methotrexate. The dose is set in accordance with the chemotherapy regimen used.
When is intraperitoneal chemotherapy prescribed?
If the malignant process is accompanied by intraperitoneal fluid production, then removal of ascites is necessary to improve the patient's condition. Oncological disease is sensitive to cytostatics, so after removal of ascites, chemicals are introduced into the cavity. This allows you to achieve greater results, since the mucous membrane of the abdominal cavity absorbs drugs well.
During clinical studies, it was proven that with intraperitoneal chemotherapy the same effect can be achieved as with intravenous administration of drugs. During postoperative treatment of stage 3 disease, when the remaining tumor nodules are no more than one centimeter, alternating administration of Paclitaxel and Cisplatin into the abdominal cavity is added, while the administration of Paclitaxel continues on the first day of each course. For such multi-month therapy during cytoreductive surgical intervention in the abdominal cavity, the installation of an infusion port system is required.
Side effects of the drug Cisplatin
From the urinary system - cumulative, dose-dependent renal failure is the main toxicity factor limiting the dose of cisplatin. The most commonly observed decrease in glomerular filtration, manifested by an increase in serum creatinine levels. Adequate hydration before and after treatment may reduce the severity of nephrotoxicity. From the hematopoietic system , hematological toxicity is also dose-dependent and cumulative. The lowest platelet and white blood cell counts are usually observed between days 18 and 32 and return to baseline levels in most patients after 39 days. Leukopenia and thrombocytopenia are more pronounced when cisplatin is used in doses exceeding 50 mg/m2. Subsequent courses of cisplatin should not be started until the platelet count exceeds 100,000 per mm3 and the white blood cell count exceeds 4000 per mm3. A significant number of patients experience anemia (decrease in hemoglobin by more than 2 g%) - usually after several courses of treatment. In severe cases, red blood cell transfusion may be required. Cisplatin therapy can cause the development of hemolytic anemia with a positive Coombs test. Subsequent courses of cisplatin treatment may cause increased hemolysis in susceptible patients. On the part of the digestive system , nausea and vomiting develop in almost all patients receiving treatment with cisplatin; in some cases, they are so pronounced that there is a need to reduce the dose or discontinue treatment. There was an increase in the activity of AST and alkaline phosphatase with clinical signs of toxic effects on the liver. From the central nervous system and sensory organs - cumulative ototoxicity develops mainly when used in high doses. Commonly observed signs of ototoxicity are tinnitus or hearing loss. Tinnitus usually lasts from several hours to 1 week after stopping therapy. Hearing loss may be unilateral or bilateral in the range of 40,000–8000 Hz (in 10–30% of patients). The frequency and severity of such hearing damage increases with repeated courses and may be irreversible. Peripheral neuropathies include stocking-glove paresthesias, areflexia, and loss of vibration sensation, especially when cisplatin is given in high doses or more frequently than recommended. These neuropathies may be irreversible. Optic neuritis has been reported following the use of cisplatin. With long-term therapy, myasthenic syndrome and seizures may also occur (if such phenomena develop, cisplatin should be discontinued). Effect on Homeostasis: Hypomagnesemia and hypocalcemia may occur and manifest as muscle excitability or spasms, tremors, carpopedal spasms, and/or tetany. Hyperuricemia may develop, especially when using doses exceeding 50 mg/m2. Uric acid levels peak 3–5 days after cisplatin administration. Allergic reactions - anaphylactoid reactions, manifested mainly by facial swelling, dizziness, tachycardia, skin rashes and arterial hypotension. Reactions usually develop within a few minutes after administration of cisplatin; to eliminate them, epinephrine, corticosteroids and/or antihistamines are administered intravenously.
Treatment for tumor regrowth
Repeated chemotherapy is carried out in case of relapse of ovarian cancer, if it is diagnosed by objective research methods, for example, ultrasound diagnostics. If during the study no new nodes are detected or old ones increase in size, but only a 2-fold increase in the CA125 marker is observed, then the patient is under supervision until symptoms of relapse appear. In more critical cases, the following methods are used:
- In a situation where the development of relapse occurs more than 6 months after treatment, then the use of a platinum drug and a drug that was not prescribed in the initial therapy is added to the regimen.
- If a relapse occurs earlier than 6 months later, the tumor is considered resistant to platinum derivatives, so it is necessary to take a medication that has not previously been used in treatment.
- When more than a year has passed since the end of postoperative chemotherapy, a positive effect can be achieved by using the same combination of medications used previously.
In any case, the possibility of surgical intervention to remove tumors in the ovaries is being considered.
Chemotherapy courses are always accompanied by many complications; they can be reduced if you undergo drug preparation before chemotherapy and rehabilitation after completion of the course. You also constantly need to adhere to nutritional support - a special diet, taking into account the initial state of health, the ability of tissues to regenerate and resist.
The main activities of the center for endovascular surgery, as well as other popular materials: Embolization in the treatment of uterine fibroids Cost of embolization of the uterine arteries for uterine fibroids Embolization of prostate vessels for adenoma
Special instructions for the use of Cisplatin
Treatment with cisplatin should only be administered by a physician experienced in chemotherapy. To reduce the risk of nephrotoxicity, patients should be hydrated before, during and after therapy. Before starting treatment, and then before administering subsequent doses, it is necessary to monitor the following parameters: renal function, including the level of glomerular filtration, urea nitrogen, creatinine in the blood; water and electrolyte balance to detect hypermagnesemia and hypercalcemia; hearing function; number of red blood cells, white blood cells and platelets; liver function and neurological status. The drug should be prescribed with caution to patients with impaired liver and kidney function. Patients receiving cisplatin should be monitored for early detection of possible anaphylactoid reactions; To treat these types of reactions, medications and necessary equipment must always be available. The risk of developing anaphylactoid reactions is increased in patients with a hereditary predisposition to allergic diseases. Children are more likely to develop ototoxicity than adults. Cisplatin has a mutagenic, teratogenic and embryotoxic effect. Cisplatin should be prescribed to women of reproductive age only in cases where the expected therapeutic effect outweighs the risk of such therapy, and patients in this case should use reliable contraception. If pregnancy occurs while using cisplatin, the patient should be informed of the possible harmful effects on the fetus.
Systemic therapy for non-small cell lung cancer (NSCLC)
Systemic therapy is the use of drugs to kill cancer cells.
The drugs travel through the bloodstream throughout the body and affect cancer cells. Typically, systemic therapy involves injecting solutions into a vein or using tablets and capsules. Types of systemic therapy for treating NSCLC include:
- chemotherapy;
- targeted therapy;
- immunotherapy.
A person may receive one type of systemic therapy or a combination of drugs. Systemic therapy may also complement treatments such as surgery and/or radiation therapy.
Is chemotherapy necessary if surgical treatment was performed at the first stage?
If treatment began with surgery, the results of surgery are used to decide whether further treatment is necessary.
The surgeon cannot always remove all the tumor he sees. Preoperative examination has certain errors, and the true spread of the tumor is visible only during surgery. If during the operation it becomes clear that the tumor has spread to structures that cannot be removed, the main component of the tumor is removed (if possible), but part of the tumor remains. This operation does not cure, but it reduces the symptoms of the disease and increases the likelihood of a positive response to chemotherapy and radiation therapy, because The smaller the tumor volume, the higher the likelihood of response to treatment.