Isturisa (Osilodrostat)

Cortisol Synthesis Inhibitor for Cushing’s Syndrome

Rx – Prescription Only Cortisol Synthesis Inhibitor
Active Ingredient
Osilodrostat
Available Forms
Film-coated tablets
Strengths
1 mg, 5 mg, 10 mg
Manufacturer
Recordati Rare Diseases
Medically reviewed | Last reviewed: | Evidence level: 1A
Isturisa (osilodrostat) is a prescription medication used to treat endogenous Cushing’s syndrome in adults. It works by blocking the key enzyme that produces cortisol in the adrenal glands, thereby reducing cortisol overproduction and alleviating the debilitating symptoms of this rare endocrine disorder. Isturisa is taken orally as a film-coated tablet, usually twice daily.
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Quick Facts About Isturisa

Active Ingredient
Osilodrostat
(phosphate monohydrate)
Drug Class
CSI
Cortisol Synthesis Inhibitor
Indication
Cushing’s
Endogenous Cushing’s Syndrome
Route
Oral
Twice daily dosing
Available Forms
Tablets
1 mg, 5 mg, 10 mg
Prescription Status
Rx Only
Prescription required

Key Takeaways About Isturisa

  • Targeted cortisol reduction: Isturisa selectively inhibits 11-beta-hydroxylase (CYP11B1), the final enzyme in cortisol biosynthesis, offering a precise mechanism to control cortisol overproduction in Cushing’s syndrome
  • Dose titration required: Treatment is individually adjusted based on cortisol level monitoring – the starting dose of 2 mg daily may be increased up to a maximum of 60 mg daily (30 mg twice daily)
  • Cardiac monitoring essential: Isturisa can prolong the QT interval – ECG monitoring is required before and during treatment, especially when combined with other QT-prolonging medications
  • Watch for adrenal insufficiency: Because Isturisa lowers cortisol, there is a risk of cortisol levels dropping too low – report symptoms such as weakness, fatigue, nausea, or dizziness immediately
  • Not for children: Isturisa is not recommended for patients under 18 years of age due to insufficient safety and efficacy data in paediatric populations

What Is Isturisa and What Is It Used For?

Isturisa (osilodrostat) is a cortisol synthesis inhibitor used to treat endogenous Cushing’s syndrome in adults. It works by blocking the enzyme 11-beta-hydroxylase (CYP11B1) in the adrenal glands, which is responsible for the final step in cortisol production, thereby reducing excessive cortisol levels in the body.

Endogenous Cushing’s syndrome is a rare but serious endocrine disorder characterised by chronic exposure to elevated cortisol levels produced by the body’s own adrenal glands. This is distinct from exogenous Cushing’s syndrome, which is caused by long-term use of corticosteroid medications. Endogenous Cushing’s syndrome most commonly results from a pituitary adenoma (a benign tumour of the pituitary gland) that secretes excess adrenocorticotropic hormone (ACTH), driving the adrenal glands to produce too much cortisol. This specific form is called Cushing’s disease. Other causes include adrenal tumours and ectopic ACTH-secreting tumours.

Prolonged cortisol excess leads to a characteristic constellation of symptoms that profoundly affects quality of life. Patients typically experience progressive weight gain, particularly around the abdomen and trunk, with thinning of the arms and legs. A rounded, full face (so-called “moon face”) and fat accumulation at the back of the neck (“buffalo hump”) are classic features. Other symptoms include easy bruising, purplish stretch marks (striae) on the skin, muscle weakness, fatigue, irregular menstrual periods in women, increased facial and body hair (hirsutism), acne, high blood pressure, high blood sugar (which may progress to diabetes), bone thinning (osteoporosis), and psychological symptoms including depression and anxiety.

Osilodrostat, the active substance in Isturisa, inhibits the enzyme 11-beta-hydroxylase (also known as CYP11B1), which catalyses the final and rate-limiting step in cortisol biosynthesis in the adrenal cortex. By blocking this specific enzyme, osilodrostat prevents the conversion of 11-deoxycortisol into cortisol. This targeted mechanism reduces cortisol overproduction while preserving other steroidogenic pathways to the greatest extent possible, although some upstream steroid precursors may accumulate as a compensatory response.

Clinical studies have demonstrated that Isturisa effectively normalises urinary free cortisol (UFC) levels in a significant proportion of patients with Cushing’s disease. In the pivotal LINC 3 study (a phase III randomised, double-blind, placebo-controlled withdrawal trial), osilodrostat achieved cortisol normalisation in approximately 77% of patients at week 48. The Endocrine Society Clinical Practice Guideline (2021) recognises steroidogenesis inhibitors, including osilodrostat, as a medical treatment option for Cushing’s syndrome, particularly when surgery is not feasible, has failed, or as a bridge to other definitive therapies.

Good to know:

Isturisa was first approved by the European Medicines Agency (EMA) in January 2020 and subsequently by the US Food and Drug Administration (FDA) in March 2020. It is marketed by Recordati Rare Diseases and represents an important addition to the limited pharmacological options available for managing Cushing’s syndrome. Unlike some older cortisol-lowering agents, osilodrostat was specifically developed and studied for this indication.

What Should You Know Before Taking Isturisa?

Before starting Isturisa, your doctor will assess your cardiac health (including an ECG), liver function, and electrolyte levels. You should not take Isturisa if you are allergic to osilodrostat or any of its ingredients. Special caution is needed in patients with heart rhythm disorders or liver disease.

Contraindications

You should not take Isturisa if you have a known allergy (hypersensitivity) to osilodrostat or to any of the other ingredients contained in the tablets. Allergic reactions may present as itching, skin rash, facial swelling, or difficulty breathing. If you experience any signs of an allergic reaction after taking Isturisa, stop taking the medication and seek immediate medical attention.

Warnings and Precautions

Speak to your doctor or pharmacist before taking Isturisa if any of the following conditions apply to you:

  • Heart disease or rhythm disorders: If you have any form of heart disease, particularly conditions that affect heart rhythm (for example, irregular heartbeat or a condition called QT prolongation), your doctor needs to know. Isturisa can prolong the QT interval on an electrocardiogram (ECG), which in rare cases may lead to serious heart rhythm disturbances. Your doctor will perform an ECG before starting treatment and at regular intervals during therapy.
  • Liver disease: If you have impaired liver function, your doctor may need to adjust your dose of Isturisa, as the drug is metabolised in the liver. Abnormal liver function tests have been observed in clinical trials, so regular blood tests to monitor liver enzymes are recommended.
  • Electrolyte imbalances: Your doctor will check your blood levels of potassium, magnesium, and calcium before starting treatment and periodically during therapy. Abnormal electrolyte levels can increase the risk of heart rhythm problems when taking Isturisa.
Warning – Signs of Adrenal Insufficiency:

Because Isturisa reduces cortisol production, there is a risk that cortisol levels may drop too low, leading to adrenal insufficiency. Contact your doctor immediately if you experience two or more of the following symptoms: weakness, unsteadiness, tiredness, loss of appetite, nausea, or vomiting. These symptoms may persist for months after discontinuation of Isturisa, and you may need additional monitoring or treatment with a cortisol replacement hormone. Your doctor will manage this by adjusting your dose or prescribing supplemental hydrocortisone.

If your Cushing’s syndrome is caused by a pituitary adenoma, your doctor may consider stopping treatment if imaging scans show that the adenoma has grown into surrounding areas. This is because reduced cortisol feedback may, in some cases, promote growth of the pituitary tumour through increased ACTH secretion (a phenomenon known as “corticotroph tumour progression”). Regular pituitary MRI monitoring is typically recommended.

Pregnancy and Breastfeeding

Isturisa should not be used during pregnancy or breastfeeding unless your doctor has specifically advised it after carefully weighing the potential benefits against the risks. Animal studies have not been conducted to adequately assess reproductive toxicity, and there is limited clinical data on the use of osilodrostat in pregnant women. If you are pregnant, think you might be pregnant, or are planning to have a baby, consult your doctor before taking this medication.

Women of childbearing potential must use effective contraception during treatment with Isturisa and for at least one week after the last dose. Before starting Isturisa, discuss appropriate contraception methods with your doctor. If you become pregnant while taking Isturisa, stop the medication and contact your doctor immediately.

It is not known whether osilodrostat passes into human breast milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue breastfeeding or to discontinue the drug, taking into account the importance of the medication to the mother.

Use in Children and Adolescents

Isturisa is not recommended for use in patients under 18 years of age. There is insufficient data on the safety and efficacy of osilodrostat in the paediatric population. Cushing’s syndrome in children is exceptionally rare, and the management typically differs from adult approaches, often prioritising surgical intervention when possible. If you have a child with Cushing’s syndrome, a paediatric endocrinologist should be involved in guiding treatment decisions.

Driving and Operating Machinery

Dizziness and fatigue have been reported during treatment with Isturisa. These effects are listed as very common side effects. If you experience dizziness, tiredness, or any impairment in alertness, you should not drive or operate machinery until the symptoms have fully resolved. Be especially cautious when starting treatment or after a dose change, as these side effects are more likely during these periods.

How Does Isturisa Interact with Other Drugs?

Isturisa can interact with several medications, particularly those that prolong the QT interval on an ECG. It is important to tell your doctor about all medications you are taking, including prescription drugs, over-the-counter medicines, and herbal supplements, before starting Isturisa.

Drug interactions are a critical consideration with Isturisa because of its potential to prolong the QT interval and its metabolism through the cytochrome P450 enzyme system. Your doctor will carefully evaluate your medication list before prescribing Isturisa and may need to adjust doses, perform additional monitoring, or substitute alternative treatments where necessary.

Major Interactions

The following medications carry significant interaction risk when combined with Isturisa and may require dose adjustment, additional monitoring, or avoidance:

Major Drug Interactions with Isturisa
Drug / Drug Class Interaction Type Clinical Significance
Quinidine, Sotalol, Amiodarone Additive QT prolongation Increased risk of serious heart rhythm disturbances; avoid combination or use with intensive ECG monitoring
Amitriptyline (and other tricyclic antidepressants) Additive QT prolongation Combined use may increase the risk of cardiac arrhythmias; ECG monitoring recommended
Antipsychotic drugs Additive QT prolongation Certain antipsychotics (e.g. haloperidol, quetiapine) prolong the QT interval; close monitoring required
Macrolide antibiotics (e.g. erythromycin, clarithromycin) QT prolongation + CYP3A4 inhibition Dual interaction risk: additive QT prolongation and potential increase in osilodrostat exposure
Fluoroquinolone antibiotics (e.g. moxifloxacin, levofloxacin) Additive QT prolongation Increased risk of cardiac arrhythmias; use alternative antibiotics where possible
Pasireotide QT prolongation + pharmacodynamic Both used for Cushing’s syndrome; combined QT-prolonging effect requires careful cardiac monitoring
Ketoconazole QT prolongation + CYP3A4 inhibition Also used for Cushing’s syndrome; dual interaction risk requires caution if switching between or combining agents

Other Notable Interactions

The following interactions are clinically relevant but generally manageable with appropriate monitoring:

  • Theophylline: Osilodrostat may inhibit the metabolism of theophylline (used for breathing problems such as asthma and COPD), potentially increasing theophylline blood levels and the risk of side effects. Your doctor may need to monitor theophylline levels and adjust your dose.
  • Tizanidine: Osilodrostat may increase the effects of tizanidine (a muscle relaxant), potentially leading to increased drowsiness and excessive lowering of blood pressure. Dose adjustments may be necessary.
  • Antihistamines: Some antihistamines (particularly older-generation agents such as terfenadine and astemizole, as well as some newer ones) can prolong the QT interval. Inform your doctor if you take any antihistamine medication.
  • Imidazole antifungals: Drugs in this class may have additive effects on QT prolongation and may also affect osilodrostat metabolism through CYP enzyme interactions.

Always inform your doctor and pharmacist about all medications, supplements, and herbal products you are currently taking or plan to take. This includes over-the-counter medicines, vitamins, and natural health products. Maintaining an up-to-date medication list is essential for safe treatment with Isturisa.

What Is the Correct Dosage of Isturisa?

The usual starting dose of Isturisa is two 1 mg tablets twice daily (2 mg total daily dose), taken approximately 12 hours apart. Your doctor will individualise your dose based on cortisol level monitoring, with a maximum recommended dose of 30 mg twice daily (60 mg total daily dose).

Isturisa dosing follows a careful dose-titration approach guided by cortisol level measurements. Unlike many medications with fixed dosing schedules, the correct dose of Isturisa varies significantly from patient to patient and is adjusted over time to achieve optimal cortisol control. Always take Isturisa exactly as your doctor has prescribed. If you are unsure about your dose, consult your doctor or pharmacist.

Adults

Standard Starting Dose

Two 1 mg tablets twice daily (1 mg in the morning + 1 mg in the evening), approximately 12 hours apart. Total daily starting dose: 2 mg.

Patients of Asian Origin or with Hepatic Impairment

One 1 mg tablet twice daily (0.5 mg morning + 0.5 mg evening is not available, so typically 1 mg twice daily = 2 mg/day, or 1 mg once daily in some patients). Your doctor will determine the appropriate lower starting dose based on your individual clinical assessment.

Dose Titration

Your doctor will adjust your dose in increments of 1–2 mg, based on regular monitoring of cortisol levels (urinary free cortisol and/or serum cortisol). Dose adjustments are typically made no more frequently than every 1–2 weeks. The goal is to normalise cortisol levels while avoiding adrenal insufficiency.

Maximum Dose

The maximum recommended dose is 30 mg twice daily (60 mg total per day). Most patients achieve cortisol normalisation at doses well below this maximum.

Isturisa tablets should be taken orally and can be taken with or without food. The tablets should be swallowed whole. Try to take your doses at the same times each day to maintain consistent blood levels of the medication.

Children and Adolescents

Isturisa is not recommended for use in patients under 18 years of age. There is insufficient data on the safety and efficacy of osilodrostat in this age group. Paediatric patients with Cushing’s syndrome should be managed by specialist endocrinologists using age-appropriate treatment strategies.

Elderly Patients

No specific dose adjustment is required for elderly patients based on age alone. However, elderly patients are more likely to have co-existing medical conditions (such as cardiac disease or hepatic impairment) that may necessitate more cautious dosing and closer monitoring. Your doctor will take your overall health status into account when determining the appropriate dose.

Missed Dose

If you forget to take a dose of Isturisa, do not take a double dose to make up for the missed one. Simply skip the missed dose and take the next dose at its scheduled time. Taking double doses can increase the risk of side effects, particularly adrenal insufficiency. If you frequently forget doses, consider setting an alarm or using a pill organiser to help you remember.

Overdose

If you have taken more Isturisa than prescribed and feel unwell – for example, experiencing weakness, unsteadiness, fatigue, nausea, or vomiting – or if someone else has accidentally taken your medication, contact your doctor or go to the nearest hospital emergency department immediately. Bring the medication packaging with you so that medical staff can identify what was taken. Overdose may lead to severe adrenal insufficiency, which requires urgent medical treatment including possible administration of intravenous hydrocortisone and supportive care.

Important – Do Not Stop Without Medical Advice:

Do not stop taking Isturisa unless your doctor tells you to. If you suddenly stop treatment, your cortisol levels may rise again, and the symptoms of Cushing’s syndrome may return. If your doctor decides to discontinue Isturisa, they may do so gradually and arrange for follow-up monitoring to ensure your cortisol levels remain stable.

What Are the Side Effects of Isturisa?

Like all medicines, Isturisa can cause side effects, although not everyone experiences them. The most common side effects include adrenal insufficiency (low cortisol), nausea, vomiting, diarrhoea, fatigue, oedema, dizziness, and rapid heartbeat. Some side effects, such as QT prolongation and adrenal insufficiency, require immediate medical attention.

Side effects of Isturisa are generally related to its mechanism of action (reducing cortisol) and the compensatory hormonal changes that occur when cortisol production is inhibited. When cortisol synthesis is blocked, the pituitary gland increases ACTH secretion in an attempt to stimulate cortisol production. This ACTH-driven stimulation can lead to accumulation of upstream steroid precursors, including androgens (male hormones), which explains some of the hormonal side effects observed with Isturisa such as hirsutism and acne.

Your doctor will monitor you closely during treatment, including regular blood tests and ECG assessments, to detect and manage side effects early. It is important to report any unusual symptoms promptly, as dose adjustments can often resolve or minimise side effects.

Very Common Side Effects

Affects more than 1 in 10 people
  • Adrenal insufficiency (low cortisol levels)
  • Nausea
  • Vomiting
  • Diarrhoea
  • Abdominal pain
  • Fatigue
  • Oedema (fluid retention causing swelling, especially around the ankles)
  • Decreased appetite
  • Dizziness
  • Tachycardia (rapid heartbeat)
  • Myalgia (muscle pain)
  • Arthralgia (joint pain)
  • Headache
  • Skin rash
  • Hypotension (low blood pressure)
  • Hirsutism (excessive hair growth on face and body)
  • Acne
  • Elevated testosterone levels (blood test finding)
  • Elevated ACTH levels (blood test finding)
  • Low potassium levels (hypokalaemia)

Common Side Effects

Affects up to 1 in 10 people
  • Malaise (general feeling of being unwell)
  • Abnormal liver function tests
  • Syncope (fainting)
  • QT prolongation (abnormal heart rhythm finding on ECG)
Seek Immediate Medical Attention:

Heart rhythm disturbances: Tell your doctor immediately if you experience fast or irregular heartbeat (even at rest), palpitations, temporary loss of consciousness, or fainting. These may be signs of QT prolongation, a potentially serious side effect that affects the heart’s electrical activity.

Adrenal insufficiency: Tell your doctor immediately if you experience two or more of the following: weakness, unsteadiness, tiredness, loss of appetite, nausea, or vomiting. This may indicate that your cortisol levels have dropped too low. Adrenal insufficiency is more likely during periods of increased physical stress (such as illness, surgery, or intense exercise). Your doctor will address this by adjusting your Isturisa dose or prescribing a cortisol replacement hormone.

Many side effects of Isturisa are related to the hormonal changes caused by the medication and can be managed through dose adjustment. The accumulation of adrenal androgen precursors (caused by the enzyme blockade) is responsible for side effects such as hirsutism, acne, and elevated testosterone levels. These effects are generally dose-dependent and may improve with dose reduction. Regular monitoring and open communication with your healthcare team are essential for optimising your treatment while minimising side effects.

How Should You Store Isturisa?

Store Isturisa at room temperature (below 25°C / 77°F) in the original packaging to protect from moisture. Keep out of the reach and sight of children. Do not use after the expiry date printed on the packaging.

Proper storage of Isturisa is important to ensure the medication remains effective and safe throughout its shelf life. Follow these storage guidelines carefully:

  • Temperature: Store at or below 25°C (77°F). Do not refrigerate or freeze the tablets.
  • Moisture protection: Keep the tablets in the original blister packaging until you are ready to take a dose. Osilodrostat is moisture-sensitive, so exposure to humidity can affect the stability of the medication.
  • Light: Store in the original carton to protect from excessive light exposure.
  • Child safety: Keep Isturisa out of the sight and reach of children. The packaging is not child-resistant, so store it in a secure location.
  • Expiry date: Do not use Isturisa after the expiry date (marked as “EXP”) printed on the carton and blister. The expiry date refers to the last day of that month.
  • Disposal: Do not dispose of unused or expired medication via household waste or down the drain. Return unused tablets to your pharmacist for safe disposal in accordance with local regulations. This helps protect the environment.

What Does Isturisa Contain?

Each Isturisa tablet contains osilodrostat as the active ingredient, available in three strengths: 1 mg, 5 mg, and 10 mg. The tablets also contain inactive ingredients (excipients) including microcrystalline cellulose, mannitol, croscarmellose sodium, and a film-coating layer.

Understanding the full composition of Isturisa is important, particularly if you have known allergies or sensitivities to specific pharmaceutical excipients. The complete composition is as follows:

Active Ingredient

Each film-coated tablet contains osilodrostat (as osilodrostat dihydrogen phosphate monohydrate) in one of three strengths: 1 mg, 5 mg, or 10 mg.

Inactive Ingredients (Excipients)

Tablet core: microcrystalline cellulose, mannitol, croscarmellose sodium (see sodium content below), magnesium stearate, and colloidal anhydrous silica.

Film coating: hypromellos, titanium dioxide (E171), iron oxides (E172), macrogol, and talc. The specific iron oxide colorants vary by tablet strength:

  • 1 mg tablets: Pale yellow, round, scored on neither side, marked “1” on one side. Contain yellow iron oxide and red iron oxide. Approximate diameter: 6.1 mm.
  • 5 mg tablets: Yellow, round, marked “5” on one side. Contain yellow iron oxide. Approximate diameter: 7.1 mm.
  • 10 mg tablets: Pale orange-brown, round, marked “10” on one side. Contain yellow iron oxide, red iron oxide, and black iron oxide. Approximate diameter: 9.1 mm.
Sodium Content:

Isturisa contains less than 1 mmol sodium (23 mg) per tablet, which means it is essentially sodium-free. This is relevant for patients on a controlled sodium diet.

Isturisa is available in packs containing 60 film-coated tablets, packaged in blister strips. If you have any questions about the composition of Isturisa or concerns about potential allergens, discuss these with your doctor or pharmacist before starting treatment.

Frequently Asked Questions About Isturisa

Cushing’s syndrome is a rare endocrine disorder caused by prolonged exposure to high levels of the hormone cortisol. Symptoms include weight gain (particularly around the trunk), a round “moon face,” easy bruising, muscle weakness, high blood pressure, and mood changes. Isturisa helps by blocking the enzyme (11-beta-hydroxylase) that produces cortisol in the adrenal glands. By reducing cortisol to normal levels, Isturisa alleviates these symptoms and improves quality of life. Clinical trials have shown that approximately 77% of patients achieve cortisol normalisation with Isturisa treatment.

Isturisa begins to reduce cortisol levels relatively quickly after starting treatment. Measurable reductions in urinary free cortisol can be observed within the first few weeks of therapy. However, the full clinical benefits – including improvement in weight, blood pressure, metabolic parameters, and physical appearance – may take several months to become apparent. The dose titration process also means that it may take several weeks to find the optimal dose for your individual needs. Your doctor will monitor your cortisol levels regularly and adjust your dose to achieve the best possible control.

Yes, Isturisa can be taken with or without food. Food does not significantly affect the absorption of osilodrostat. However, taking the tablets at the same times each day (approximately 12 hours apart) helps maintain consistent drug levels in the blood and ensures optimal cortisol suppression throughout the day. If you experience nausea or stomach discomfort, taking Isturisa with a light meal may help reduce these gastrointestinal side effects.

Regular ECG monitoring is essential because Isturisa can prolong the QT interval, which is a measure of the heart’s electrical cycle. A prolonged QT interval can, in rare cases, lead to serious heart rhythm problems. ECG tests allow your doctor to detect any changes early and take appropriate action, such as adjusting your dose. Blood tests are needed to monitor your cortisol levels (to ensure they are in the target range), electrolytes (particularly potassium, magnesium, and calcium, as imbalances can worsen QT prolongation), liver function, and hormone levels (including ACTH and testosterone). These tests help your doctor fine-tune your treatment for maximum benefit and safety.

Isturisa is not a cure for Cushing’s syndrome; rather, it is a medical treatment that controls the condition by reducing cortisol production. Surgery to remove the underlying cause (such as a pituitary or adrenal tumour) remains the first-line curative treatment when possible. Isturisa is typically used when surgery is not feasible, has not been successful, is declined by the patient, or as a bridge therapy before or after surgery. Some patients may need to take Isturisa long-term if the underlying cause of their Cushing’s syndrome cannot be definitively treated. If you stop taking Isturisa without addressing the underlying cause, cortisol levels are likely to rise again and symptoms may return.

If you feel unwell during treatment, particularly if you experience symptoms that could indicate adrenal insufficiency (weakness, unsteadiness, extreme tiredness, loss of appetite, nausea, or vomiting), contact your doctor immediately. These symptoms may mean that your cortisol levels have dropped too low. During periods of physical stress – such as illness, surgery, or significant emotional stress – your body’s cortisol needs increase, and your doctor may temporarily adjust your Isturisa dose or prescribe supplemental hydrocortisone. Carry a medical alert card or bracelet indicating that you are taking a cortisol-lowering medication, so healthcare providers can act quickly in emergencies.

References & Medical Sources

This article is based on the following peer-reviewed sources and international medical guidelines:

  1. European Medicines Agency (EMA). Isturisa (osilodrostat) – Summary of Product Characteristics. First authorised January 2020. Available at: www.ema.europa.eu
  2. Pivonello R, Fleseriu M, Newell-Price J, et al. Efficacy and safety of osilodrostat in patients with Cushing’s disease (LINC 3): a multicentre phase III study with a double-blind, randomised withdrawal phase. Lancet Diabetes Endocrinol. 2020;8(9):748–761. doi:10.1016/S2213-8587(20)30240-0
  3. Nieman LK, Biller BMK, Findling JW, et al. Treatment of Cushing’s Syndrome: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2015;100(8):2807–2831. Updated 2021. doi:10.1210/jc.2015-1818
  4. US Food and Drug Administration (FDA). Isturisa (osilodrostat) prescribing information. Approved March 2020. Available at: www.accessdata.fda.gov
  5. Fleseriu M, Castinetti F. Updates on the role of adrenal steroidogenesis inhibitors in Cushing’s syndrome: a focus on novel therapies. Pituitary. 2016;19(6):643–653. doi:10.1007/s11102-016-0742-1
  6. World Health Organization (WHO). Model List of Essential Medicines. 23rd Edition, 2023. Available at: www.who.int
  7. Lacroix A, Feelders RA, Stratakis CA, Nieman LK. Cushing’s syndrome. Lancet. 2015;386(9996):913–927. doi:10.1016/S0140-6736(14)61375-1
  8. British National Formulary (BNF). Osilodrostat. National Institute for Health and Care Excellence (NICE). Available at: bnf.nice.org.uk

Medical Editorial Team

This article has been written and reviewed by our medical editorial team, comprising board-certified specialists in endocrinology, clinical pharmacology, and internal medicine.

Medical Writing

iMedic Medical Editorial Team – Specialists in Endocrinology and Clinical Pharmacology

Medical Review

iMedic Medical Review Board – Independent expert panel following international guidelines

Evidence Level

Level 1A – Based on systematic reviews, RCTs, and international clinical practice guidelines

Guidelines Followed

Endocrine Society, EMA, FDA, WHO, BNF – GRADE evidence framework

Conflict of Interest: None declared. iMedic receives no funding from pharmaceutical companies. All content is editorially independent. Read our editorial standards.