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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Pazopanib
Generic Name
Pazopanib Hydrochloride
Active Ingredient
PazopanibCategory
Kinase Inhibitor [EPC]
Salt Form
Hydrochloride
Variants
2
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Pazopanib, you must consult a qualified healthcare professional.
Detailed information about Pazopanib
Pazopanib is a potent multi-tyrosine kinase inhibitor used to treat advanced renal cell carcinoma and soft tissue sarcoma by blocking proteins that signal cancer cells to grow and divide.
The standard recommended starting dose for Pazopanib in adults with either advanced renal cell carcinoma or advanced soft tissue sarcoma is 800 mg taken orally once daily.
Your healthcare provider may adjust this dose based on how well you tolerate the medication. If you experience significant side effects, your doctor might reduce the dose in 200 mg increments (e.g., decreasing from 800 mg to 600 mg, and then to 400 mg if necessary). If a dose of 400 mg is still not tolerated, the medication is typically discontinued. It is vital to never change your dose without explicit instructions from your oncology team.
Pazopanib is not approved for use in pediatric patients. Clinical studies in juvenile animals have shown that Pazopanib can cause severe issues with organ development and bone growth (epiphyseal growth plate abnormalities). Because of these risks, safety and effectiveness in children have not been established, and the drug is generally avoided in patients under the age of 18.
For patients with mild to moderate kidney dysfunction, no initial dose adjustment is typically required, as very little of the drug is excreted through the kidneys. However, there is limited data for patients with severe renal impairment or those on dialysis; in these cases, the drug must be used with extreme caution.
The liver is responsible for breaking down Pazopanib, so liver function is critical.
In clinical trials, no overall differences in safety or effectiveness were observed between patients over 65 and younger patients. However, older adults may be more sensitive to certain side effects, such as high blood pressure or heart issues, and should be monitored closely.
Proper administration is crucial for the safety and efficacy of Pazopanib.
If you miss a dose of Pazopanib, take it as soon as you remember. However, if your next scheduled dose is less than 12 hours away, skip the missed dose and return to your regular schedule. Do not take two doses at once to make up for a missed one. If you vomit after taking a dose, do not take an extra dose; simply wait until your next scheduled time.
An overdose of Pazopanib can lead to severe hypertension (high blood pressure), extreme fatigue, and liver damage. If you suspect an overdose, seek emergency medical attention or contact a Poison Control Center immediately. Treatment for overdose is supportive, as there is no specific antidote for Pazopanib. Doctors will monitor your blood pressure and liver enzymes closely.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop taking the medication without medical guidance, as this could allow your cancer to grow more rapidly.
Most patients taking Pazopanib will experience some side effects. While many are manageable, they require consistent communication with your doctor.
Pazopanib is a high-alert medication that requires careful supervision by an oncologist. Because it affects the growth of blood vessels and multiple organ systems, the risks are significant. Patients must be proactive in monitoring their health and reporting changes immediately. It is essential to keep all follow-up appointments and laboratory visits while taking this medication.
Hepatotoxicity: Pazopanib can cause severe liver injury that can lead to liver failure or death. In clinical trials, increases in liver enzymes (ALT and AST) and bilirubin were frequently observed. Monitoring is mandatory. Liver function tests must be conducted at baseline, at weeks 3, 5, 7, and 9, then at month 3 and month 4, and periodically thereafter. If you have pre-existing liver disease, you must inform your doctor, as this significantly increases your risk.
Certain medications should never be used with Pazopanib because the interaction is too dangerous to manage.
There are certain situations where Pazopanib must never be used because the risks far outweigh any potential benefits.
Pazopanib is classified as a significant reproductive hazard. Based on its mechanism of action (inhibiting angiogenesis), it is expected to cause fetal harm when administered to a pregnant woman. Animal studies have shown that even at doses lower than the human equivalent, Pazopanib causes embryo-fetal lethality and severe structural abnormalities.
It is not known if Pazopanib is excreted in human milk. However, because many drugs are excreted in milk and because of the potential for serious adverse reactions in a nursing infant (including effects on growth and organ development), breastfeeding is not recommended
Pazopanib is a multi-target tyrosine kinase inhibitor (TKI). It works by competing with adenosine triphosphate (ATP) for the binding site on the intracellular domain of various receptors. By binding to these sites, it prevents the phosphorylation and subsequent activation of downstream signaling pathways.
The primary targets of Pazopanib are:
By inhibiting these pathways simultaneously, Pazopanib exerts a 'multi-pronged' attack on the cancer, making it difficult for the tumor to develop resistance through a single pathway.
Common questions about Pazopanib
Pazopanib is primarily used to treat two specific types of cancer: advanced renal cell carcinoma (a type of kidney cancer) and advanced soft tissue sarcoma (cancers in muscles, fat, or other soft tissues). For kidney cancer, it is often used as a first-line treatment when the cancer has spread to other parts of the body. For soft tissue sarcoma, it is typically prescribed for patients who have already tried other chemotherapy treatments. It works by blocking the blood supply to tumors and stopping the signals that tell cancer cells to grow. Only a qualified oncologist can determine if this medication is appropriate for your specific diagnosis.
The most common side effects experienced by patients taking Pazopanib include diarrhea, high blood pressure (hypertension), hair color changes (often turning white), and fatigue. Many patients also report nausea, vomiting, and a loss of appetite which can lead to weight loss. Because it affects the liver, elevations in liver enzymes are also very common and require regular blood tests. Most of these side effects appear within the first few weeks of starting the medication. While many are manageable with supportive care, some can become serious, so constant communication with your healthcare team is essential.
While there is no absolute prohibition against drinking alcohol while on Pazopanib, it is generally advised to limit consumption significantly. Both Pazopanib and alcohol are processed by the liver, and Pazopanib is known to carry a high risk of liver toxicity (hepatotoxicity). Combining the two could place additional stress on the liver and increase the risk of serious liver damage. Furthermore, alcohol can worsen side effects like nausea and dehydration caused by diarrhea. You should discuss your alcohol intake with your doctor to ensure it does not interfere with your treatment or safety.
No, Pazopanib is not safe during pregnancy and is known to cause severe birth defects or the death of an unborn baby. The drug works by stopping the growth of new blood vessels, a process that is vital for the development of a fetus and the placenta. Women who can become pregnant must use highly effective birth control during treatment and for at least two weeks after their last dose. Men taking Pazopanib should also use protection if their partner can become pregnant. If you suspect you have become pregnant while taking this medication, you must notify your doctor immediately.
Pazopanib begins working at the molecular level shortly after you start taking it, but its effects on the tumor are usually not visible on scans for several weeks. Most doctors will perform the first follow-up imaging (like a CT scan) after about 8 to 12 weeks of treatment to assess if the tumor has shrunk or stopped growing. However, some side effects, like an increase in blood pressure, can occur within the first week, which indicates the drug is active in your system. The duration of treatment continues as long as the cancer is responding and the side effects remain manageable.
You should never stop taking Pazopanib suddenly without consulting your oncologist first. Stopping the medication can allow the cancer cells to begin growing and spreading again, potentially more rapidly than before. If you are experiencing severe side effects, your doctor may decide to pause the medication or lower the dose, but this must be done under medical supervision. If you must stop the drug for surgery, your doctor will provide a specific schedule for when to stop and when it is safe to restart. Always follow your medical team's guidance regarding the discontinuation of chemotherapy.
If you miss a dose of Pazopanib, you should take it as soon as you remember, provided that your next scheduled dose is more than 12 hours away. If your next dose is due in less than 12 hours, you should skip the missed dose entirely and take your next dose at the regular time. Never take two doses at once to make up for a missed one, as this significantly increases the risk of toxic side effects. If you frequently forget your doses, consider using a pill organizer or a phone alarm to help you stay on schedule. Consistency is vital for keeping the cancer under control.
Pazopanib is much more likely to cause weight loss rather than weight gain. This is due to common side effects like loss of appetite, changes in the way food tastes, nausea, and chronic diarrhea. However, if you notice sudden weight gain accompanied by swelling in your ankles, legs, or shortness of breath, you should contact your doctor immediately. This could be a sign of heart failure or fluid retention, which are serious side effects of the medication. Monitoring your weight daily can help you and your doctor distinguish between nutritional weight loss and dangerous fluid buildup.
Pazopanib has many serious interactions with other medications, including common over-the-counter drugs and herbal supplements. It interacts heavily with drugs processed by the liver's CYP3A4 enzyme and medications that reduce stomach acid, like proton pump inhibitors (PPIs). Taking these together can either make Pazopanib dangerously toxic or completely ineffective. It also interacts with medications that affect heart rhythm or blood clotting. Because of these risks, you must provide your doctor with a complete list of everything you take, including vitamins and herbs like St. John's Wort, before starting treatment.
Yes, generic versions of Pazopanib have been approved by the FDA and are available in many regions. Generic medications contain the same active ingredient and meet the same quality and safety standards as the brand-name version (Votrient). The availability of a generic can significantly reduce the cost of treatment for many patients. However, whether you receive the brand-name or the generic may depend on your insurance coverage and local pharmacy stock. Regardless of which version you take, the instructions for taking the medication on an empty stomach and monitoring for side effects remain exactly the same.
Other drugs with the same active ingredient (Pazopanib)
> Warning: Stop taking Pazopanib and call your doctor immediately or seek emergency care if you experience any of the following:
With prolonged use, Pazopanib can lead to chronic conditions that require ongoing management:
The FDA has issued a Black Box Warning for Pazopanib regarding Hepatotoxicity (Liver Toxicity). Severe and sometimes fatal liver damage has been observed in clinical trials. Your doctor must perform liver function tests (ALT, AST, and bilirubin) before you start the drug and every 4 weeks for at least the first 4 months of treatment. Periodic monitoring will continue thereafter. If your liver enzymes rise significantly, the drug may need to be paused or permanently discontinued.
Report any unusual symptoms, no matter how minor they seem, to your healthcare provider immediately. Early intervention is key to managing the side effects of Pazopanib.
While taking Pazopanib, you will need frequent testing:
Pazopanib can cause significant fatigue and occasional dizziness. You should see how the medication affects you before driving or operating heavy machinery. If you feel excessively tired or faint, avoid these activities.
There is no direct contraindication for alcohol, but since both Pazopanib and alcohol are processed by the liver, heavy drinking can increase the risk of hepatotoxicity. It is best to limit alcohol consumption significantly while on this treatment.
Do not stop taking Pazopanib suddenly unless directed by your doctor. If you stop the drug, your tumor may begin to grow again. There is no known withdrawal syndrome, but the underlying cancer may progress rapidly upon cessation.
> Important: Discuss all your medical conditions, especially liver, heart, or bleeding disorders, with your healthcare provider before starting Pazopanib.
Pazopanib does not typically interfere with the chemical results of lab tests, but it causes physiological changes that will be reflected in your labs, such as:
For each major interaction, the primary mechanism is usually the inhibition or induction of the CYP3A4 enzyme or the alteration of gastric pH. The clinical consequence is either increased toxicity (which can be fatal) or reduced efficacy (allowing the cancer to grow). The management strategy is typically to avoid the interacting drug or to adjust the dose of Pazopanib under strict supervision.
> Important: Tell your doctor about ALL medications, over-the-counter drugs, supplements, and herbal products you are taking. Even 'natural' products can have deadly interactions with chemotherapy.
While there is no documented cross-sensitivity with other tyrosine kinase inhibitors (like Sunitinib or Sorafenib), patients who have had severe, idiosyncratic reactions to other drugs in this class should be monitored with extra vigilance, as they may share similar metabolic pathways or target-organ sensitivities.
> Important: Your healthcare provider will evaluate your complete medical history, including any history of blood clots, bleeding, or heart disease, before prescribing Pazopanib.
Pazopanib is not recommended for use in children. Safety has not been established in patients under 18 years of age. In juvenile animal studies, Pazopanib caused severe toxicity, particularly in the lungs, liver, and bones. Most notably, it caused abnormalities in the epiphyseal growth plates (the areas at the ends of long bones where growth occurs), which could lead to permanent growth failure or skeletal deformities.
Approximately 30% to 40% of patients in clinical trials for RCC and STS were 65 years of age or older. While no overall differences in the drug's effectiveness were noted between older and younger patients, elderly patients may be at a higher risk for certain side effects, such as:
Careful monitoring of blood pressure and kidney function is particularly important in this population.
Since only about 4% of Pazopanib is excreted in the urine, kidney dysfunction does not significantly change the levels of the drug in the body. No dose adjustment is required for patients with a Creatinine Clearance (CrCl) > 30 mL/min. However, there is no data for patients with a CrCl < 30 mL/min or those on dialysis; these patients should be treated with extreme caution.
Liver function is the most critical factor in Pazopanib dosing.
> Important: Special populations require individualized medical assessment and often more frequent laboratory monitoring.
The pharmacodynamic effect of Pazopanib is most clearly seen in its effect on blood pressure. Hypertension is considered an 'on-target' effect, meaning it is a sign that the drug is successfully inhibiting the VEGF pathway. Studies have shown a correlation between the development of hypertension and improved clinical outcomes (progression-free survival) in kidney cancer patients. However, this must be balanced against the risks of high blood pressure.
| Parameter | Value |
|---|---|
| Bioavailability | ~14-21% (highly variable, increased by food) |
| Protein Binding | >99% (primarily to albumin and alpha-1 acid glycoprotein) |
| Half-life | ~31 hours |
| Tmax | 2 to 4 hours |
| Metabolism | Primarily Hepatic (CYP3A4; minor CYP1A2, 2C8) |
| Excretion | Fecal (82%), Renal (4%) |
Pazopanib is classified as a Kinase Inhibitor [EPC]. It belongs to the broader category of targeted therapies and antineoplastic agents. Related medications in the same class include Sunitinib (Sutent), Sorafenib (Nexavar), and Axitinib (Inlyta). Unlike traditional chemotherapy, which kills all rapidly dividing cells, Pazopanib is designed to be more selective for the pathways used by cancer cells.