Idelalisib is prescribed to treat patients with cancer of the blood or bone marrow such as chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma, and follicular B-cell non-Hodgkin lymphoma (FL) whose cancer has returned after treating with some anti-cancer medicines.
Idelalisib is recommended to treat chronic lymphocytic leukemia (CLL) in combination with rituximab for patients who can tolerate rituximab alone.
It works by interfering with some specific protein signals that prevent the cancer cells to multiply resulting in stopping the spread of cancer cells.
Idelalisib can be used as a first-line treatment in CLL only if specific gene changes of 17p deletion or TP53 mutation are confirmed.
Idelalisib should not be used as a first-line treatment in patients with chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma, and follicular B-cell non-Hodgkin lymphoma (FL).
It is also not recommended to treat follicular lymphoma with a combination of other chemotherapy medicines such as rituximab or bendamustine.
Idelalisib should also not to be used in patients with-
• Allergic to idelalisib
• Pregnancy and breastfeeding
• Children below 18 years of age as the safety and effectiveness of idelalisib have not been studied on these groups.
Caution is required while treating patients with-
• Active liver disease
• Severe diarrhea
The recommended adult dose of idelalisib is 150 mg two times daily.
Dose modification or adjustment of idelalisib or withholding the treatment temporarily can be considered in patients who show side effects and can be started again once the symptoms are reduced.
The reduced dose of idelalisib is 100 mg taken twice daily.
Treatment with idelalisib can be permanently stopped in the following cases-
• High level of liver enzymes and bilirubin
• Life-threatening diarrhea
• Low level of neutrophils and platelets
• Confirmation of Pneumocystis jirovecii pneumonia (PJP) infection
However, dose modification of idelalisib is not required in mild to moderate kidney disease or if lymphocytosis or increased levels of lymphocytes (a type of white blood cell) are observed.
• Idelalisib is available as a tablet and can be taken by mouth either with or without food.
• Take the idelalisib tablets at the same time every day exactly as directed by the doctor.
• Tablets of idelalisib should be swallowed as a whole with sufficient quantity of water without splitting or crushing the tablet contents.
• Do not stop taking idelalisib without consulting the doctor and continue taking until the disease is under control or treatment can be tolerated.
• Women of childbearing age should follow effective contraception to avoid pregnancy and must continue contraception for at least one month after taking the last dose of idelalisib.
• Lactating mothers should not breastfeed their babies during idelalisib treatment to protect the babies from harm, and must withhold for at least a month after stopping idelalisib.
• Allergic or hypersensitivity reactions can occur including severe skin reactions during idelalisib treatment and patients must be instructed to consult their physician without delay, if such reactions occur.
• Patients under treatment with idelalisib are more vulnerable to get infections; therefore patients must be advised to report to their physician if any symptoms of infections occur. They must be informed not to ignore even a high-grade fever.
• Similarly, periodic monitoring of blood counts or neutrophils should be performed during idelalisib treatment to assess the presence of neutropenia which is an indicator of an infection.
• Monitor liver function in patients taking idelalisib by frequently testing the levels of liver enzymes (ALT & AST) and bilirubin to recognize and treat liver dysfunction such as jaundice or liver toxicity at an earlier stage.
• Severe diarrhea and colitis may occur in patients under idelalisib treatment, and patients must be taken to the emergency center if the number of bowel movements exceeds six or more, and started on rehydration therapy.
• There is a possibility of pneumonitis in patients taking idelalisib; therefore any new or worsening of airway symptoms such as a cough or difficulty in breathing should be treated accordingly.
• Severe stomach pain occurs during idelalisib treatment due to the erosion or perforation of the intestine which should be informed to the doctor immediately to treat the severity.
• Gastrointestinal: Nausea, vomiting, loose stools, stomach pain, loss of appetite, heartburn, and indigestion
• Nervous system: Inability to sleep, weakness or severe sluggishness
• Respiratory: Cough, wheezing or shortness of breath, swelling of air passages, stuffy nose, chest discomfort
• Infections: Urinary tract infections, herpes of mouth, sepsis or bacterial infection in the blood, infection of the lungs or pneumonia
• Others: Joint pain, fever, chills, rashes
• The missed dose of an idelalisib tablet can be taken immediately provided it is remembered within 6 hours.
• If the dose is missed for longer than 6 hours neglect the missed dose and take the next dose as per the next scheduled time.
• Women of childbearing age should perform a pregnancy test and should start idelalisib treatment only if the test is negative.
• Male patients who have female partners of reproductive potential should use effective barrier methods of contraception for at least three months from the last dose of idelalisib.
Idelalisib should not be used with the following drugs to avoid some severe side effects
• Antiarrhythmic drugs (Quinidine, amiodarone)
• Ergot alkaloids (Ergotamine, dihydroergotamine)
• Cholesterol-lowering drugs (Simvastatin, lovastatin)
• Midazolam, diazepam
• Blood pressure treating drugs (Amlodipine, diltiazem, nifedipine)
• Antifungal agents (Ketoconazole, voriconazole)
• Store idelalisib tablets at room temperature between 20°C and 25°C.
• Keep the idelalisib tablets in their original container and do not use if the seal of the container is broken or missing.
• Keep away from excess moisture and sunlight.