Indications
Elexacaftor is used to treat cystic fibrosis (CF) in people who have at least one F508del mutation or another responsive change in the CFTR gene. It is only available combined with Tezacaftor and Ivacaftor in a triple-combination treatment, which is taken together with a separate Ivacaftor dose. It is prescribed by a CF specialist after genetic testing.
How It Works
CF is caused by a faulty CFTR protein, a channel that normally moves chloride (salt) and water across cell surfaces. Elexacaftor is a next-generation CFTR corrector. It works at a different site from Tezacaftor, and together they help more of the faulty protein fold correctly and reach the cell surface. Ivacaftor then holds the channel open. This triple action thins mucus, improves breathing and nutrition, and lowers sweat chloride levels.
Dosage and Administration
Take exactly as prescribed by your CF specialist. Usually the combination tablet(s) are taken in the morning and an Ivacaftor tablet in the evening, about 12 hours apart, each with fat-containing food such as eggs, butter, cheese, whole milk, yoghurt or nuts. Dosing in children depends on age and weight. Doses are reduced in moderate liver disease or when taken with certain interacting medicines.
Interactions
- Strong CYP3A inducers (Rifampicin, Rifabutin, Carbamazepine, Phenytoin, Phenobarbital, St John’s wort) markedly reduce its levels; avoid.
- Strong and moderate CYP3A inhibitors (Ketoconazole, Itraconazole, Posaconazole, Voriconazole, Clarithromycin, Fluconazole, Erythromycin) increase its levels; the dose must be reduced.
- Avoid grapefruit and Seville oranges.
- It can raise levels of some medicines, such as Digoxin, Ciclosporin, Tacrolimus, Warfarin and some statins; monitoring may be needed.
Contraindications
Do not take if you are allergic to Elexacaftor, Tezacaftor, Ivacaftor or any ingredient of the tablets.
Side Effects
Common side effects include headache, upper respiratory infections, stomach pain, diarrhoea, rash, raised liver enzymes, raised creatine kinase (a muscle enzyme), stuffy nose, flu-like symptoms and raised bilirubin. Rarely, serious liver injury and liver failure have been reported. Mood changes such as anxiety, low mood or trouble sleeping have been reported. Cataracts have been seen in some children.
Get urgent medical help if you have yellow skin or eyes, dark urine, pain in the upper right abdomen, severe nausea or vomiting, confusion, a severe rash, swelling of the face or difficulty breathing, or thoughts of harming yourself.
Pregnancy and Lactation
Experience in pregnancy is limited. Treatment may restore fertility in women with CF, so discuss contraception or pregnancy plans with your specialist. Some hormonal contraceptives may be linked to rash with this treatment; ask your doctor. It is not known if meaningful amounts pass into breast milk; discuss with your doctor before breastfeeding.
Precautions and Warnings
- Liver tests (ALT, AST and bilirubin) are checked before starting, every month for the first 6 months, then every 3 months, then yearly.
- Not recommended in severe liver disease.
- Children should have eye examinations before and during treatment.
- Report any change in mood or behaviour.
Overdose
There is no specific antidote. An overdose may increase side effects. Contact your doctor or the nearest hospital for monitoring and supportive care.
Therapeutic Class
CFTR corrector (next-generation); cystic fibrosis transmembrane conductance regulator modulator.
Storage
Store below 30°C in a dry place, away from light, in the original pack, and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.