Efficacy and function of paclitaxel

Taxol, also known as taxol, paclitaxel, taxol, etc., is a new type of anti-cancer drug that has been very concerned and popular in recent years, especially in the treatment of ovarian cancer and breast cancer. It is a first-line drug for the treatment of these two diseases. If it is used in combination with cisplatin, it can effectively fight against lung cancer. Let's take a look at the efficacy and effect of paclitaxel.

Efficacy and function of paclitaxel

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

Usage and dosage of paclitaxel

1. First ask the patient if he has a history of allergy, and check the data of leukocytes and platelets. Patients with history of allergy and leukopenia / thrombocytopenia should be used with caution.

2. Paclitaxel can cause allergic reactions. Take 20 mg of dexamethasone 12 hours and 6 hours before administration, 50 mg of diphenhydramine orally and 300 mg of cimetidine intravenously 30 minutes before administration.

3. The commonly used dose of paclitaxel is 135 × 175 mg / m2. The injection should first be added to normal saline or 5% glucose solution 500 to 1000 ml, glass bottle or non-polyethylene infusion device should be used, and special hose and 0.22 μ m microporous membrane should be used for filtration.

4. Blood pressure, heart rate and breathing should be measured every 15 minutes after drip, and pay attention to allergic reaction.

5. Paclitaxel was usually infused for 3 hours.

6. The hemogram should be checked at least twice a week after paclitaxel injection, and can be repeated after 3-4 weeks.

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

Adverse reactions of paclitaxel

1. Allergic reaction: the incidence rate is 39%, of which the incidence of severe allergic reaction is 2%. Most of them are type 1 allergic reactions, characterized by bronchial spastic dyspnea, urticaria and hypotension. Almost all reactions occurred in the first 10 minutes after administration.

2. Myelosuppression: it is the main dose-limited toxicity, characterized by neutropenia and thrombocytopenia, which usually occurs 8 ~ 10 days after medication. The incidence of severe neutrophils was 47%, and the incidence of 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 abnormalities, and the incidence of severe neurotoxicity is 6%.

4. Cardiovascular toxicity: there may be hypotension and asymptomatic short-term bradycardia. Muscle and joint pain: the incidence is 55%, occurs in the joints of the extremities, and the incidence and severity are dose-dependent.

5. Gastrointestinal reactions: the incidence of nausea, vomiting, diarrhea and mucositis was 59% / 43% and 39% respectively, generally mild and moderate.

6. Hepatotoxicity: increased ALT,AST and AKP.

7. Hair loss: the incidence is 80%.

8. Local reaction: local inflammation of intravenous infusion and extravasation of drugs.

Notes on paclitaxel

1. Hematological toxicity: in order to limit the increase of dose, G-CSF should be used when white blood cells are less than 1500 / cubic millimeter, and blood components should be transfused when platelet is less than 30000 / mm.

2, allergic reaction: in addition to pretreatment, if there are only mild symptoms such as flushing, skin reaction, heart rate slightly faster, blood pressure slightly lower, there is no need to stop medication, the dripping speed can be slowed down. However, if there are serious reactions such as low blood pressure, angioneurotic edema, dyspnea, systemic urticaria, should be stopped and given appropriate treatment. Patients with severe allergies should not be treated with paclitaxel next time.

3. Nervous system: the most common is finger numbness. About 4% of patients have obvious sensory and motor disorders and decreased tendon reflexes, especially at high doses, and major seizures have been reported during drip.

4. Heart and blood vessels: transient tachycardia and hypotension are more common and generally do not need to be dealt with. However, it should be closely observed in the first hour of drip, and it is not necessary to observe every hour except for patients with severe conduction block.

5. Joints and muscles: about half of the patients will feel joint and muscle pain 2-3 days after medication, which is related to the dose used. It usually recovers within a few days. Muscle pain gets worse in patients who are given G-CSF.

6. Hepatobiliary system: as paclitaxel is mostly excreted from bile, patients with hepatobiliary diseases should be carefully observed. Of the thousands of patients, about 8% had elevated bilirubin, 23% had elevated alkaline phosphatase, and 18% had elevated glutamic oxaloacetic transaminase. However, there is no data to show that paclitaxel has serious damage to liver function.