Efficacy and function of paclitaxel

Paclitaxel, also known as paclitaxel, viologen, paclitaxel and so on. It is a new anticancer drug that has attracted much attention and popularity in recent years, especially for ovarian cancer and breast cancer. It is a first-line drug to treat these two diseases. If cisplatin is used in combination, it can effectively fight lung cancer. Let's take a look at the efficacy and function of paclitaxel!

Efficacy and function of paclitaxel

Paclitaxel is mainly used for ovarian cancer and breast cancer, and has certain curative effect on lung cancer, colorectal cancer, melanoma, head and neck cancer, lymphoma and brain tumor. Microtubules are components of eukaryotic cells. Under normal circumstances, there is a dynamic balance between microtubule and tubulin dimer. Paclitaxel can make them lose this dynamic balance, induce and promote tubulin polymerization, prevent depolymerization and stabilize microtubules. These effects lead to the inability of cells to form spindles and spindles during mitosis, inhibit cell division and proliferation, and thus play an anti-tumor role.

Usage and dosage of paclitaxel

1. Ask the patient if he has allergic history, and check the data of white blood cells and platelets. People with allergic history and low white blood cell/platelet should use it with caution.

2. Paclitaxel can cause allergic reaction. Dexamethasone 20mg was taken 12 hours and 6 hours before administration, diphenhydramine 50mg was taken orally, and cimetidine 300mg was injected intravenously 30~60 minutes before administration.

3. The usual dosage of paclitaxel is 135~ 175mg/m2. Firstly, the injection was added into 500~ 1000 ml physiological saline or 5% glucose solution. Use a glass bottle or a non-polyethylene infusion set, and use a special hose and a 0.22 micron microporous filter membrane for filtration.

4. After the drip starts, measure blood pressure, heart rate and breathing every 15 minutes. Pay attention to whether there is an allergic reaction.

5. Paclitaxel is usually instilled for 3 hours.

6. Check the blood picture at least twice a week after paclitaxel injection, and repeat the examination as appropriate after 3-4 weeks.

7. Paclitaxel can be used in combination with cisplatin, carboplatin, ifosfamide, fluorouracil, adriamycin and VP- 16. When the hemogram is low, G-CSF can be used, or paclitaxel plus G-CSF can be used for preventive administration.

Adverse reactions of paclitaxel

1. Allergic reaction: the incidence was 39%, and the incidence of severe allergic reaction was 2%. Most of them are allergic reactions of type 1, which are characterized by bronchospasm, dyspnea, urticaria and hypotension. Almost all the reactions occurred in the first 10 minutes after taking the medicine.

2. Bone marrow suppression: it is the main dose-limiting toxicity, which is characterized by neutropenia and rare thrombocytopenia, generally occurring 8~ 10 days after taking the medicine. The incidence of severe neutrophils was 47%, and severe thrombocytopenia was 5%. Anemia is more common.

3. Neurotoxicity: The incidence of peripheral neuropathy is 62%, the most common manifestations are mild numbness and sensory abnormality, and the incidence of severe neurotoxicity is 6%.

4. Cardiovascular toxicity: there may be hypotension and asymptomatic short-term bradycardia. Joint pain: the incidence rate is 55%, which is common in joints of limbs. Incidence and severity are related to dose.

5. Gastrointestinal reactions: The incidence rates of nausea, vomiting, diarrhea and mucositis were 59%/43% and 39% respectively, generally mild to moderate.

6. Hepatotoxicity: Alanine aminotransferase, aspartate aminotransferase and AKP increased.

7. Hair loss: the incidence rate is 80%.

8. Local reaction: local inflammation of vein where drugs are injected and drug extravasation.

Precautions for Paclitaxel

1. Hematological toxicity: In order to limit the main factors of dose increase, G-CSF is generally used as an assistant when white blood cells are below 1500/ mm, and blood components are given when platelets are below 30,000/mm. ..

2. Allergic reaction: In addition to pretreatment, if there are only mild symptoms such as flushing, skin reaction, slightly faster heart rate and slightly lower blood pressure, then I don't need to stop taking the medicine. You can slow down the drip speed. However, if there are serious reactions such as hypotension, angioneurotic edema, dyspnea and urticaria, the drug should be stopped and properly handled. Patients with severe allergies should not be treated with paclitaxel next time.

3. Nervous system: Numbness of fingers and toes is the most common disease. About 4% of patients, especially in large doses, can have obvious sensory and motor dysfunction and decreased tendon reflex. There are individual reports that grand mal appeared during infusion.

4. Heart and blood vessels: Transient tachycardia and hypotension are common and generally do not require treatment. But in the first hour of infusion, close observation should be made.

5. Joints and muscles: About half of patients will feel joint and muscle pain 2-3 days after taking the medicine, which is related to the dosage used. It usually recovers within a few days. Patients receiving G-CSF will have more severe muscle pain.

6. Hepatobiliary system: Because paclitaxel is mostly excreted from bile, patients with hepatobiliary diseases should be carefully observed. In the data of thousands of cases, about 8% patients had elevated bilirubin, 23% patients had elevated alkaline phosphatase and 18% patients had elevated aspartate aminotransferase. However, there is no data showing that paclitaxel has serious damage to liver function.

7. Other matters: Although digestive tract reactions are common, they are generally not serious, and a few may have diarrhea and mucositis. Mild hair loss is also common.

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