Trastuzumab (Herceptin)

Trastuzumab (pronounced [tras TU zoo mab]) is also known by the brand name Herceptin. Herceptin is an antineoplastic (anti-cancer) drug that belongs to a class called Anti-HER2. It is a type of chemotherapy that prevents cancer cells from multiplying and restricts their growth.

什么是化疗？

Chemotherapy is a cancer treatment in which certain drugs are used to kill cancerous cells. These drugs are usually cytotoxic chemical substances that are toxic to the cells, restrict their growth, prevent their division, and ultimately kill the cells. 

How Is Herceptin Used?

Herceptin has been approved by the Food and Drug Administration (FDA) to treat different types of breast cancer, endometrial cancer, and stomach cancer. It can be prescribed alone or with other anti-cancer medications. 

可用配方

Herceptin is available as a solution for intravenous injection only. It is most commonly available in 150 mg strength. The total duration of therapy typically should not exceed 1 year (52 weeks), but this may vary depending on the patient’s condition and cancer severity. 

使用方法

Herceptin is typically dosed to be given once every 1 to 3 weeks, depending on cancer type and severity. Verify the correct dose and frequency with your provider. The dose should not be more or less than what is prescribed. The dose is determined using the patient’s body weight. The initial dose (also known as the loading dose) is typically infused over 90 minutes if tolerated, and subsequent infusions (maintenance doses) can be infused over 30 – 90 minutes. 

Do not administer Herceptin with dextrose in water (D5W) or with any other medications. It should be mixed with bacteriostatic or sterile water for injection only and diluted with normal saline. Herceptin should NOT be administered as an IV push or rapid bolus. Trastuzumab is available alone or in combination with other drugs. Different trastuzumab products are NOT interchangeable; only administer exact medication prescribed.

漏服剂量

This medicine needs to be administered on a fixed schedule. If you miss a dose, contact your physician for further instructions immediately. 

Typically, if the dose is missed by one week or less, the usual maintenance dose should be given as soon as possible (do not wait until the next planned cycle). Subsequent maintenance doses should be administered 1 to 3 weeks later (based on the patient’s normal maintenance dose schedule).

If a dose is missed by over one week, a re-loading dose should be administered over 90 minutes as soon as possible. The usual maintenance dose is then administered 1 to 3 weeks later (based on the patient’s normal maintenance dose schedule).

贮存

As there are lots of different variations of trastuzumab, storage times vary by product; refer to the individual product labeling for details. Prior to reconstitution, vials should be stored in the refrigerator. Some products should be stored in intact vials in the original carton to protect from light. Some solutions are preservative-free, and therefore, they should be used immediately. Others can be refrigerated for up to 24 hours (depending on the product or vial size). Do not freeze or shake Herceptin vials. 

What To Avoid While Taking Herceptin

While taking Herceptin therapy, you must follow some precautions. Always tell your physician about any medications you are already taking. 未经医生或药剂师事先同意，请勿服用任何药物（即使是草药、维生素或非处方药）. They may have some significant interactions with Herceptin.

Pregnancy and Herceptin

Exposure to Herceptin during pregnancy may result in a decrease in amniotic fluid, which can severely impact the fetus and lead to delayed growth and malformations. Pregnancy status must be checked prior to starting Herceptin therapy in women of childbearing age, and effective contraception must be used during treatment and for 7 months after the last dose. Herceptin may cause fetal harm and is therefore not recommended for women who are breastfeeding during therapy. Breastfeeding should also be avoided for at least 7 months after the last dose. 

副作用

As with any other medication, you may encounter side effects while taking Herceptin. A few things to remember are:

• 您可能不会出现以下列出的所有副作用。许多人可能几乎没有副作用。
• 副作用的严重程度可能因人而异，因此不要将您的副作用与其他人的经历进行比较。
• 停止治疗后，大多数副作用都会改善。
• 这些副作用大多数情况下都很容易控制，可以通过重新调整剂量来控制 Herceptin 或使用其他药物治疗症状。请咨询您的医生或药剂师，了解可用的治疗方案。
• 不要隐瞒任何症状；如果您感到任何不适，请毫不犹豫地告诉您的医生或药剂师。

笔记：此列表并未涵盖所有副作用。如有任何疑问，请咨询医生。 

Some of the more serious side effects of Herceptin are listed below:

Weight Loss

It is common for Herceptin to cause weight loss due to decreased appetite while taking this medication. 

心脏并发症 

There may be cardiac complications with the use of Herceptin like hypertension, left ventricular heart failure (LVHF), arrhythmias, or thromboembolism (which can include heart attack or stroke). Hypertension can be managed with antihypertensive therapy. Monitoring for LVHF is warranted prior to initiation of therapy, every 3 months during therapy, and every 6 months for 2 years after therapy is completed. 

Kidney Complications

Herceptin may cause kidney complications, leading to a condition called glomerulopathy, and can lead to heart failure if left untreated. Glomerulopathy is a syndrome where protein leaks out of the kidneys and is found in the urine. This can be detected by taking a urine test at the doctor’s office. 

Hepatitis B Reactivation

There is a high chance of getting hepatitis B with Herceptin use. It is essential to screen for hepatitis B prior to initiating Herceptin therapy. Signs of hepatitis B include yellowing of the skin and eyes or excessive tiredness. If you have any of these symptoms, seek medical advice from your physician immediately. 

Lung Damage

In some cases, Herceptin can potentially cause lung damage and conditions like acute respiratory distress syndrome (ARDS), pulmonary fibrosis, pulmonary edema (fluid in lungs), and others. Lung effects usually occur within 24 hours after administration. Patients with preexisting lung conditions may be at a higher risk. If you experience difficulty breathing, seek medical help immediately. 

Bone, Joint, Back, and Muscle Pain

Another common side effect is bone, joint, back, or muscle pain. Adequate rest and hydration may help reduce potential pain. Get physician approval prior to taking any over-the-counter medications for pain relief.

Infusion-related Reactions

Infusion-related reactions with Herceptin treatment most commonly occur during treatment or within 24 hours after the first infusion. Infusion reactions may consist of fever and chills, and may also manifest as nausea, vomiting, headache, dyspnea, dizziness, rash, hypotension, and weakness. If shortness of breath, swelling of the mouth or tongue, or drop in blood pressure occurs, the infusion should be stopped immediately. If you experience a severe infusion reaction, the infusion can be re-attempted with appropriate premedications like Tylenol or Benadryl.

Other common side effects may include:

• 恶心或呕吐
• 腹泻
• Flu or cold-like symptoms
• 腹痛
• 口味改变
• 睡眠困难
• Mouth sores or irritation

防范措施

Unless approved by your physician, Herceptin is generally not recommended in patients with a risk of cardiac complications.

• Risk factors can include a history of heart disease, high blood pressure, high amounts of fat or cholesterol in blood (dyslipidemia), history of heart attack or stroke, etc. 
• Herceptin is known for causing left ventricular heart failure. If signs of LVHF are apparent, discontinuation may be warranted. 
• Patients with other conditions (like diabetes, obesity, smoking, and being 60 or older) may also be at a higher risk for cardiac complications. 

常见问题解答

Is Herceptin a chemo agent?

化疗药物 are those that are used in the management of various cancers. Herceptin kills the cancer cells. Thus, it is a chemo agent that is advised as a treatment option for various cancer patients. 

How should Herceptin be taken?

Herceptin is available as an intravenous injection only. It is typically dosed to be given once every 1 to 3 weeks, depending on cancer type and severity. The dose is determined using the patient’s body weight. The loading dose is typically infused over 90 minutes if tolerated, and subsequent infusions (maintenance doses) are typically infused over 30 – 90 minutes.