What is Osilodrostat: Uses, Dosage, Side Effects and More

Osilodrostat is a prescription medication that helps control excessive cortisol production in your body. It's specifically designed for people with Cushing's disease when surgery isn't possible or hasn't worked completely. This medication works by blocking an enzyme your body uses to make cortisol, helping restore a healthier balance of this important hormone.

What is Osilodrostat?

Osilodrostat is a targeted medication that reduces cortisol levels in your body. It belongs to a class of drugs called steroidogenesis inhibitors, which simply means it interferes with your body's natural cortisol production process.

Your adrenal glands normally produce cortisol to help manage stress and regulate various body functions. However, when you have Cushing's disease, your body makes too much cortisol, leading to serious health problems. Osilodrostat helps bring these levels back into a healthier range by blocking a specific enzyme called 11β-hydroxylase that's essential for cortisol production.

This medication is relatively new to the market and represents an important advancement in treating cortisol excess. It's manufactured as oral tablets that you take by mouth, making treatment more convenient than some older alternatives.

What is Osilodrostat Used For?

Osilodrostat is primarily used to treat Cushing's disease in adults. This condition occurs when a small tumor in your pituitary gland causes your adrenal glands to produce too much cortisol.

Your doctor might prescribe osilodrostat if you've had pituitary surgery that didn't completely resolve your Cushing's disease, or if surgery isn't a safe option for you. The medication is also used when other treatments haven't adequately controlled your cortisol levels.

The goal of treatment is to reduce your cortisol to normal levels, which can help improve symptoms like high blood pressure, diabetes, muscle weakness, and mood changes. Some people also experience improvements in their physical appearance, including reduced facial puffiness and easier weight management.

How Does Osilodrostat Work?

Osilodrostat works by blocking a key enzyme in your body's cortisol production pathway. Think of it as putting a brake on your cortisol factory when it's working overtime.

Specifically, it inhibits 11β-hydroxylase, an enzyme that's essential for the final step of cortisol production in your adrenal glands. When this enzyme is blocked, your body simply can't make as much cortisol, even if the signal from your pituitary gland is still telling it to do so.

This medication is considered moderately strong in its effects. It can significantly reduce cortisol levels, but your doctor will start you on a low dose and gradually increase it to find the right balance for your body. The goal is to lower your cortisol enough to improve your symptoms without dropping it too low, which could cause its own set of problems.

How Should I Take Osilodrostat?

You should take osilodrostat exactly as your doctor prescribes, typically twice daily with food. Taking it with meals helps your body absorb the medication better and can reduce stomach upset.

It's best to take your doses at roughly the same times each day, such as with breakfast and dinner. This helps maintain steady levels of the medication in your system. You can take it with any type of food, though having some fat in your meal may help with absorption.

Swallow the tablets whole with a full glass of water. Don't crush, chew, or break them, as this can affect how the medication is released in your body. If you have trouble swallowing pills, talk to your doctor about alternatives rather than trying to modify the tablets yourself.

Your doctor will likely start you on a low dose and gradually increase it based on your cortisol levels and how you're responding to treatment. This careful approach helps minimize side effects while finding the most effective dose for you.

How Long Should I Take Osilodrostat For?

You'll likely need to take osilodrostat for an extended period, potentially years or even long-term. Cushing's disease is a chronic condition that typically requires ongoing management to keep cortisol levels controlled.

Your doctor will monitor your cortisol levels regularly through blood and urine tests, usually every few weeks initially, then less frequently once your levels stabilize. These tests help determine if your current dose is working effectively or if adjustments are needed.

Some people may be able to stop the medication if they have successful pituitary surgery later, or if their condition goes into remission. However, this decision should always be made with your doctor's guidance, as stopping suddenly can cause your cortisol levels to spike again.

The length of treatment really depends on your individual situation, how well you respond to the medication, and whether other treatment options become available or appropriate for you.

What Are the Side Effects of Osilodrostat?

Like all medications, osilodrostat can cause side effects, though not everyone experiences them. Understanding what to expect can help you feel more prepared and know when to contact your doctor.

The most common side effects you might experience include nausea, fatigue, headache, and diarrhea. These effects are usually mild to moderate and often improve as your body adjusts to the medication over the first few weeks of treatment.

Here are the more frequent side effects people report:

• Nausea and stomach discomfort
• Fatigue and feeling generally tired
• Headaches
• Diarrhea or loose stools
• Decreased appetite
• Swelling in your legs or ankles
• Muscle and joint pain

These common side effects are generally manageable and often lessen over time as your body adapts to the treatment.

There are some more serious side effects that require immediate medical attention, though they're less common. These include signs that your cortisol levels may have dropped too low, such as severe fatigue, nausea and vomiting, low blood pressure, or confusion.

Here are the more serious side effects to watch for:

• Severe weakness or extreme fatigue
• Persistent vomiting
• Dizziness or fainting
• Irregular heartbeat
• Signs of liver problems like yellowing of skin or eyes
• Severe mood changes or depression

If you experience any of these more serious symptoms, contact your doctor immediately or seek emergency medical care.

Rare but potentially serious side effects include adrenal insufficiency, where your cortisol drops too low, and QT prolongation, which affects your heart rhythm. Your doctor will monitor you with regular blood tests and heart rhythm checks to watch for these uncommon but important complications.

Who Should Not Take Osilodrostat?

Osilodrostat isn't suitable for everyone, and your doctor will carefully evaluate whether it's safe for you. Certain health conditions or medications can make this treatment inappropriate or require special precautions.

You should not take osilodrostat if you're pregnant or breastfeeding, as it can harm your baby. If you're a woman of childbearing age, your doctor will discuss reliable birth control methods before starting treatment.

Several health conditions may make osilodrostat unsuitable for you:

• Severe liver disease
• Certain heart rhythm disorders
• Severe kidney disease
• Active severe infections
• Known allergies to osilodrostat or its ingredients

Your doctor will also be cautious about prescribing osilodrostat if you have a history of heart problems, as the medication can occasionally affect heart rhythm.

Certain medications can interact with osilodrostat, making it less effective or increasing the risk of side effects. These include some antibiotics, antifungal medications, and drugs that affect heart rhythm. Always tell your doctor about all medications, supplements, and herbal products you're taking.

If you have diabetes, your doctor will monitor you extra carefully, as osilodrostat can affect blood sugar levels. Similarly, if you have high blood pressure, your medication needs may change as your cortisol levels improve.

Osilodrostat Brand Name

Osilodrostat is sold under the brand name Isturisa in the United States and Europe. This is the only brand name currently available for this medication.

Isturisa is manufactured by Recordati Rare Diseases and was specifically developed for treating Cushing's disease. Since it's a relatively new medication, approved by the FDA in 2020, there aren't any generic versions available yet.

When you pick up your prescription, you'll see "Isturisa" on the label, and the tablets are typically light blue, film-coated tablets. The medication comes in different strengths, and your doctor will prescribe the appropriate dose for your situation.

Osilodrostat Alternatives

If osilodrostat isn't suitable for you or doesn't work well enough, there are other treatment options available for managing Cushing's disease. Your doctor can help you explore these alternatives based on your specific situation.

Other medications that can help control cortisol levels include ketoconazole, mitotane, and mifepristone. Each works slightly differently and has its own set of benefits and potential side effects.

Here are the main medication alternatives:

• Ketoconazole - An antifungal medication that also blocks cortisol production
• Mitotane - Directly affects the adrenal glands to reduce cortisol
• Mifepristone - Blocks cortisol's effects rather than reducing production
• Pasireotide - A newer injection that can help in some cases

Non-medication treatments might also be options depending on your situation, including repeat pituitary surgery, radiation therapy, or in severe cases, surgical removal of the adrenal glands.

Your doctor will consider factors like your overall health, previous treatments, and how well you've responded to other medications when discussing alternatives. The goal is always to find the most effective treatment with the fewest side effects for your particular case.

Is Osilodrostat Better Than Ketoconazole?

Both osilodrostat and ketoconazole can effectively reduce cortisol levels, but they each have different advantages and considerations. The "better" choice really depends on your individual health profile and treatment response.

Osilodrostat was specifically designed for Cushing's disease and tends to have more predictable effects on cortisol levels. It's generally better tolerated by most people, with fewer interactions with other medications compared to ketoconazole.

Ketoconazole has been used longer for Cushing's disease treatment, so doctors have more experience with it. However, it can cause more significant liver problems and has more drug interactions, requiring careful monitoring.

Here's how they compare in key areas:

• Effectiveness: Both can significantly reduce cortisol levels
• Side effects: Osilodrostat generally has fewer serious side effects
• Drug interactions: Ketoconazole has more significant interactions
• Monitoring needs: Ketoconazole requires more frequent liver function tests
• Cost: This can vary depending on your insurance coverage

Your doctor will consider your medical history, other medications you're taking, and your previous treatment responses when choosing between these options. Some people may even use them in combination or switch from one to the other based on their response and tolerability.