Tunib contains Sunitinib is an oral multi-kinase inhibitor used to treat various types of cancer. It works by blocking multiple protein kinases that play a role in tumor growth and blood vessel formation. Sunitinib is primarily used in the treatment of renal cell carcinoma (RCC), gastrointestinal stromal tumor (GIST), and pancreatic neuroendocrine tumors (pNET).

Mechanism of Action

Sunitinib inhibits several key kinases involved in cancer cell proliferation and angiogenesis, including:

• VEGFR (Vascular Endothelial Growth Factor Receptor): Blocks tumor blood vessel formation (angiogenesis).
• PDGFR (Platelet-Derived Growth Factor Receptor): Inhibits tumor cell growth and spread.
• c-Kit: Plays a crucial role in the development of gastrointestinal stromal tumors (GIST).
• RET, FLT3, and other kinases: Involved in various cancer cell survival and proliferation pathways.

By inhibiting these kinases, Sunitinib slows down cancer progression and reduces tumor growth.

Medical Uses

Renal Cell Carcinoma (RCC):

• Used for the treatment of advanced or metastatic kidney cancer.

Gastrointestinal Stromal Tumor (GIST):

• Used when imatinib (Gleevec) is ineffective in treating GIST tumors.

Pancreatic Neuroendocrine Tumors (pNET):

• For fast-growing pancreatic tumors that cannot be surgically removed.

Other Investigational Uses:

• Being studied for the treatment of breast cancer, lung cancer, and melanoma.

Sunitinib is an effective targeted therapy drug for various cancers, particularly kidney, gastrointestinal, and pancreatic cancer. Its multi-kinase inhibition mechanism helps control tumor growth and angiogenesis. However, it can cause significant side effects, so it should be used under medical supervision. Regular monitoring and dose adjustments can maximize benefits while minimizing risks.

Dosage and Administration

• Sunitinib is available in capsule form.
• The usual dosage is 50 mg per day for 4 weeks, followed by a 2-week break (4/2 cycle).
• For GIST and pNET, the typical dose is 37.5 mg daily, taken continuously.
• It can be taken with or without food.

Side Effects

Common Side Effects

• High blood pressure (hypertension)
• Fatigue and weakness
• Gastrointestinal issues – nausea, vomiting, diarrhea, stomach pain
• Skin changes – hand-foot syndrome (redness, swelling, pain), hair color changes
• Increased bleeding risk – gum bleeding, nosebleeds

Serious Side Effects

• Heart issues – high blood pressure, irregular heartbeat
• Liver toxicity – elevated liver enzymes
• Muscle and bone weakness
• Thyroid dysfunction

If any severe side effects occur, seek medical attention immediately.

Drug Interactions

Sunitinib is metabolized by the CYP3A4 enzyme, so certain drugs can affect its effectiveness:

• CYP3A4 Inhibitors (e.g., ketoconazole, ritonavir) – Can increase sunitinib levels, leading to more side effects.
• CYP3A4 Inducers (e.g., rifampin, carbamazepine) – Can decrease sunitinib effectiveness.
• Avoid grapefruit and grapefruit juice as they can interfere with CYP3A4 metabolism.

Precautions

• Liver function: Patients with liver disease require close monitoring.
• Heart disease: Regular cardiovascular monitoring is recommended.
• Pregnancy: Sunitinib is classified as Category D, meaning it can harm an unborn baby.
• Before surgery: May increase the risk of bleeding, so consult a doctor before any surgical procedure.

Contraindications

• Patients allergic to Sunitinib or its components should not use it.
• Not recommended for pregnant or breastfeeding women.
• Use with caution in patients with severe heart disease.