Drug Interaction Report

Consumer information for this interaction is not currently available.

GENERALLY AVOID: Coadministration with strong inducers of CYP450 3A4 or the pregnane X receptor (PXR) (e.g. carbamazepine, phenytoin, rifampin, St. John's wort) may decrease the plasma concentrations of vamorolone leading to a lack of efficacy. Vamorolone is partially metabolized in vitro by CYP3A4. The clinical significance of this interaction is unknown.

MANAGEMENT: Some authorities recommend considering the use of alternative treatments that are not strong inducers of CYP3A4 during concomitant use with vamorolone due to reduced vamorolone efficacy. No dose adjustments are recommended. The possibility of decreased corticosteroid effects should be considered. Patients should be monitored for signs and symptoms of steroid withdrawal and secondary renal insufficiency, including anorexia, hypoglycemia, nausea, vomiting, weight loss, muscle wasting, fatigue, weakness, dizziness, postural hypotension, depression, and adrenal crisis manifested as inability to respond to stress (e.g., illness, infection, surgery, trauma).

Ivacaftor should be taken with fat-containing foods such as eggs, avocados, nuts, meat, butter, peanut butter, cheese pizza, and whole-milk dairy products to help with its absorption. Do not consume grapefruit juice or any food that contains grapefruit or Seville oranges during treatment with ivacaftor unless directed otherwise by your doctor. Grapefruit juice can significantly increase the blood levels of ivacaftor. This may increase the risk and/or severity of serious side effects such as liver damage. Call your doctor immediately if you have fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark urine, pale stools, and/or yellowing of the skin or eyes, as these may be signs and symptoms of liver damage. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Grapefruit juice may increase the blood levels and effects of vamorolone. This may increase the risk and/or severity of side effects such as swelling, weight gain, electrolyte abnormalities, high blood pressure, high blood glucose, muscle weakness, depression, mood swings, acne, thinning skin, stretch marks, easy bruising, cataracts, glaucoma, excessive growth of facial or body hair, and abnormal distribution of body fat, especially in the face, neck, back, and waist. Other side effects that may occur include decreased ability to fight infections, increased risk of developing infections, and inadequate response to stress such as infection, surgery, trauma, or a severe asthma attack. Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.