Table of Contents
- What is Osilodrostat?
- What Conditions Does Osilodrostat Treat?
- How Does Osilodrostat Work?
- How Effective is Osilodrostat?
- How is Osilodrostat Taken?
- What are the Side Effects of Osilodrostat?
- Use in Special Populations
- Ongoing Research on Osilodrostat
What is Osilodrostat?
Osilodrostat is a medication used to treat certain hormonal disorders. It is also known by the brand name Isturisa and was previously called LCI699 during its development.[1] Osilodrostat comes in the form of tablets that are taken by mouth.[2]
What Conditions Does Osilodrostat Treat?
Osilodrostat is primarily used to treat Cushing’s syndrome, especially a type called Cushing’s disease. Cushing’s syndrome is a condition where the body produces too much of a hormone called cortisol.[2] Cortisol is normally produced by the adrenal glands and helps regulate many important functions in the body. However, when too much cortisol is produced, it can cause a variety of symptoms and health problems.
Specifically, osilodrostat has been studied for use in:[3][4]
- Cushing’s disease (caused by a tumor in the pituitary gland)
- Ectopic Cushing’s syndrome (caused by tumors outside the pituitary gland)
- Adrenal tumors causing excess cortisol
How Does Osilodrostat Work?
Osilodrostat works by blocking an enzyme called 11β-hydroxylase, which is involved in producing cortisol in the adrenal glands. By inhibiting this enzyme, osilodrostat reduces the amount of cortisol the body makes.[1] This helps bring cortisol levels back to a normal range in people with Cushing’s syndrome.
How Effective is Osilodrostat?
Clinical trials have shown osilodrostat to be effective in treating Cushing’s syndrome:
- In one study, about 86% of patients had normal cortisol levels after 24 weeks of treatment.[1]
- Another trial found that 77% of patients maintained normal cortisol levels for 36 weeks while on osilodrostat.[5]
- Osilodrostat has also been shown to improve many of the symptoms and health problems associated with Cushing’s syndrome, such as high blood pressure, diabetes, and weight gain.[3]
How is Osilodrostat Taken?
Osilodrostat is taken as tablets by mouth, usually twice a day. The dose is typically started low and then gradually increased over time based on cortisol levels and how well the medication is tolerated.[2] Common doses range from 2 mg to 30 mg twice daily, but the exact dose varies for each patient. Regular blood and urine tests are done to monitor cortisol levels and adjust the dose as needed.
What are the Side Effects of Osilodrostat?
Common side effects of osilodrostat may include:[1][5]
- Nausea
- Headache
- Fatigue
- Adrenal insufficiency (low cortisol levels)
Use in Special Populations
Studies have looked at how osilodrostat is processed by the body in people with liver or kidney problems:
- For patients with mild to moderate liver problems, no dose adjustment is typically needed.[6]
- For patients with kidney problems, the medication may stay in the body longer, so dose adjustments may be necessary.[7]
Ongoing Research on Osilodrostat
Research on osilodrostat is ongoing to learn more about its long-term use and effectiveness in different types of Cushing’s syndrome. Some current studies are:
- Looking at the long-term safety and effectiveness of osilodrostat in patients with various types of Cushing’s syndrome[2]
- Studying a treatment approach that combines osilodrostat with steroid replacement therapy[8]
- Evaluating osilodrostat in patients with Cushing’s syndrome not caused by Cushing’s disease[4]



