Idelalisib

Idelalisib is a prescription medication used to treat certain types of leukemia and lymphoma. Idelalisib belongs to a group of drugs called phosphoinositide 3-kinase (PI3K) delta inhibitors.

PI3K delta signaling is active in many B-cell leukemias and lymphomas, and by inhibiting the protein, idelalisib blocks several cellular signaling pathways that drive B-cell ability to live. 

This medication comes in tablet form and is taken typically 2 times a day, with or without food. Do not chew, divide, or break idelalisib tablets. Swallow idelalisib tablets whole.

Common side effects of idelalisib include diarrhea, fever, fatigue, nausea, cough, pneumonia, abdominal pain, chills and rash.

Idelalisib is a prescription medication used to treat:

• in combination with rituximab for the treatment of relapsed chronic lymphocytic leukemia in patients for whom rituximab alone would be considered appropriate therapy due to other co-morbidities and as monotherapy 
• relapsed follicular B-cell non-Hodgkin lymphoma (FL)
• relapsed small lymphocytic lymphoma (SLL) in patients who have received at least two prior therapies

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Idelalisib may be found in some form under the following brand names:

• Zydelig

Serious side effects have been reported with idelalisib. See the “Idelalisib Precautions” section.

Common side effects of idelalisib include the following:

• diarrhea
• fever
• fatigue
• nausea
• cough
• pneumonia
• abdominal pain
• chills
• rash

This is not a complete list of idelalisib side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• medications that increase the activity of the enzyme CYP3A4 such as carbamazepine (Tegretol, Equetro, Carbatrol), phenobarbital, phenytoin (Dilantin), rifampin (Rifadin), St John's wort, and nimodipine (Nimotop)
• medications that block a protein in the body (CYPA4) such as some macrolide antibiotics (clarithromycin, telithromycin), some HIV protease inhibitors (indinavir, nelfinavir, ritonavir, saquinavir), some HCV protease inhibitors (boceprevir, telaprevir), some azole antifungals (ketoconazole, itraconazole, posaconazole, voriconazole), conivaptan (Vaprisol), delavirdine (Rescriptor), and nefazodone
• medications that use the enzyme CYP3A4 such as budesonide (Entocort), astemizole (Hismanal), cisapride (Propulsid), cyclosporine (Neoral, Gengraf, Sandimmune), darifenacin (Enablex), dihydroergotamine (Migranal), fentanyl (Abstral, Fentora, Onsolis, Actiq), pimozide (Orap), quinidine (Cardioquin, Duraquin, Quinact), sirolimus (Rapamune), tacrolimus (Prograf), terfenadine (Seldane), fluticasone (Flovent HFA, Flonase), eletriptan (Relpax), lovastatin (Mevacor), quetiapine (Seroquel), sildenafil (Viagra, Revatio), and simvastatin (Zocor)

This is not a complete list of idelalisib drug interactions. Ask your doctor or pharmacist for more information.

Serious side effects have been reported with idelalisib including the following:

• Severe cutaneous reactions: Tell your doctor right away if you develop a severe skin reaction.
• Severe diarrhea or colitis. Idelalisib may cause severe diarrhea or colitis. Tell your doctor if the number of bowel movements in a day increases by six or more.
• Liver dysfunction. Idelalisib may cause significant elevations in liver enzymes. Your doctor will order liver tests while you take idelalisib. Tell your doctor right away if you notice symptoms of liver dysfunction including jaundice, bruising, abdominal pain, or bleeding.
• Pneumonitis (inflammation of lung tissue). Tell your doctor if you notice any new or worsening respiratory symptoms including cough or difficulty breathing.
• Intestinal perforation (a hole in the intestines). Tell your doctor right away if you have abdominal pain.
• Anaphylaxis: Tell your doctor right away if you notice any signs of anaphylaxis.
  • chest pain
  • swelling of the face, eyes, lips, tongue, arms, or legs
  • difficulty breathing or swallowing
  • Hives, itchiness
• Low white blood cell count (neutropenia). A low white blood cell count can cause you to get infections, which may be serious. Serious illness or death can happen if an infection is not treated right away when white blood cell counts are very low. Tell your doctor right away if you have any of the following signs or symptoms of an infection:
  • fever
  • shortness of breath
  • pain or burning on urination
  • chills
  • cough
• Fetal harm. Idelalisib may cause fetal harm when administered to a pregnant woman. Women should avoid pregnancy during treatment with idelalisib. Women should not breastfeed while taking idelalisib.

Do not take idelalisib if you:

• are allergic to idelalisib or to any of its ingredients
• have a history of serious allergic reactions, including anaphylaxis and toxic epidermal necrolysis (TEN)

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of idelalisib, there are no specific foods that you must exclude from your diet when receiving this medication.

Before taking idelalisib, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to idelalisib or to any of its ingredients
• have liver problems
• are pregnant or plan to become pregnant
• are breastfeeding or plan to breastfeed

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Idelalisib falls into category D. Based on findings in animals, idelalisib may cause fetal harm when administered to a pregnant woman. Idelalisib was teratogenic in animals. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be aware of the potential hazard to the fetus.

Women should avoid pregnancy during treatment with idelalisib. If contraceptive methods are being considered, women should use adequate contraception during therapy and for at least one month after completing therapy.

Tell your doctor if you are breastfeeding or plan to breastfeed.

It is not known if idelalisib crosses into human milk. Because many medications can cross into human milk and because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using idelalisib.

Take idelalisib exactly as prescribed.

This medication comes in tablet form and is taken typically 2 times a day, with or without food.

Do not chew, divide, or break idelalisib tablets. Swallow idelalisib tablets whole.

If a dose of idelalisib is missed by less than 6 hours, take the missed dose right away and take the next dose as usual. If a dose of idelalisib is missed by more than 6 hours, wait and take the next dose at the usual time. Do not take two doses of idelalisib at the same time.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The recommended starting dose of Zydelig (idelalisib) is 150 mg twice daily.

Your doctor may adjust your dose if you experience certain adverse effects.

If you take too much idelalisib, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

• Store idelalisib between 20–30°C (68–86°F).

BOXED WARNING: FATAL and SERIOUS TOXICITIES: HEPATIC, SEVERE DIARRHEA, COLITIS, PNEUMONITIS and INTESTINAL PERFORATION

• Fatal and/or serious hepatotoxicity occurred in 14 percent of idelalisib-treated patients. Monitor hepatic function prior to and during treatment. Interrupt and then reduce or discontinue idelalisib as recommended.
• Fatal, serious, and/or severe diarrhea or colitis occurred in 14 percent of idelalisib-treated patients. Monitor for the development of severe diarrhea or colitis. Interrupt and then reduce or discontinue idelalisib as recommended.
• Fatal and serious pneumonitis can occur. Monitor for pulmonary symptoms and bilateral interstitial infiltrates. Interrupt or discontinue idelalisib as recommended.
• Fatal and serious intestinal perforation can occur in idelalisib-treated patients. Discontinue idelalisib for intestinal perforation.