FDA Approves First Intranasal Diuretic, Enbumyst

The FDA has approved Corstasis Therapeutics’ Enbumyst (bumetanide nasal spray), the first self-administered nasal diuretic for the treatment of edema associated with congestive heart failure and hepatic and renal disease, including nephrotic syndrome in adults, according to a recent news release. It is expected to be available in the United States in the fourth quarter of 2025.

Enbumyst is the spray formulation of bumetanide, available as an oral tablet or injections for intravenous or intramuscular administration. Bumetanide was originally approved in 1983.

Enbumyst will utilize Aptar Pharma’s Unidose System, which is already used in more than 30 FDA- and EMA-approved therapies.

“We are pleased to see our Unidose System continually supporting innovative therapies that expand access and convenience for patients,” Alex Theodorakis, president of Aptar Pharma Prescription, said in the news release. “This approval reflects the growing potential of nasal delivery platforms in systemic treatment and reinforces Aptar’s commitment to enabling patient-centric solutions.”

Today’s approval adds to the continuing trend of nasally administered therapeutics, such as neffy, ARS Pharmaceuticals’ needle-free epinephrine nasal spray and AstraZeneca’s FluMist, the nasal spray flu vaccine, both approved by the FDA in 2024.

Edema is characterized by a buildup of fluid in body tissues, which causes swelling in various parts of the body, such as the feet, hands, and face. It can be caused by something as simple as diet or it can be a disease symptom. It affects approximately 20% of patients with heart failure, 50% of patients with kidney disease and 50% of liver disease patients.

Edema is one of the main causes of readmission in patients with these diseases. Approximately 6.7 million Americans currently have heart or liver failure, which accounts for billions of dollars spent on healthcare expenditures.

“Enbumyst offers the potential to change the standard of care by enabling earlier, outpatient intervention,” Anuradha Lala-Trindade, M.D., director of heart failure research at the Mount Sinai Fuster Heart Hospital in New York, said in a news release. “This innovation may meaningfully improve outcomes while potentially easing the economic burden on the healthcare system.”

The daily recommended dosage of Enbumyst is 0.5 mg to 2 mg once daily, based on patient response, according to the prescribing information.

This approval is based on the results of a clinical pharmacology study of 68 adult patients. Study participants were all given all three forms of bumetanide and then monitored for 10 days. Enbumyst demonstrated a 33% faster absorption rate than oral bumetanide.

Efficacy was measured using diuresis, natriuresis and potassium urine excretion levels. The effect of a 2 mg spray of Enbumyst was similar to the effect of a 2 mg bumetanide oral tablet over 0 to 8 hours and a 2 mg bumetanide IV injection over 0 to 24 hours.

Safety was studied in two clinical studies on 84 participants. The most common adverse reactions were hypovolemia, a condition in which blood plasma becomes too low, which occurred in 4.8% of patients and headache, which was reported by 3% of patients.

Patients should alternate the spray between the right and left nostrils, and it should not be administered against the wall of the nose. Enbumyst is not intended for chronic use.