Fenfluramine Side Effects

Medically reviewed by Drugs.com. Last updated on Dec 12, 2023.

Applies to fenfluramine: oral solution.

Important warnings This medicine can cause some serious health issues

REMS:

FDA approved a REMS for fenfluramine to ensure that the benefits outweigh the risks.

The REMS may apply to one or more preparations of fenfluramine and consists of the following: elements to assure safe use and implementation system.

See the FDA REMS page ([Web]).

Side effects include:

Decreased appetite, somnolence, sedation, lethargy, diarrhea, constipation, abnormal echocardiogram, fatigue, malaise, asthenia, ataxia, balance disorder, gait disturbance, increased BP, drooling, salivary hypersecretion, pyrexia, upper respiratory tract infection, vomiting, decreased weight, falls, status epilepticus.

For healthcare professionals

Applies to fenfluramine: oral solution, oral tablet.

General

The more commonly reported adverse effects have included decreased appetite and weight, somnolence, sedation, lethargy, diarrhea, constipation, increased blood pressure, gait disturbances, balance disorder, pyrexia, asthenia, vomiting, fall, and status epilepticus.^[Ref]

Cardiovascular

• Very common (10% or more): Abnormal echocardiogram (up to 23%), increased blood pressure (up to 13%)
• Common (1% to 10%): Increased heart rate^[Ref]

Abnormal echocardiogram included trace and mild mitral regurgitation, and trace aortic regurgitation, which are considered physiologic. Valvular heart disease and pulmonary arterial hypertension were evaluated in the clinical studies via echocardiography for up to 3 years in duration and no patient developed findings consistent with either condition. During the open-label extension study, trace mitral regurgitation and trace aortic regurgitation were reported in 14% and 0.4%, respectively. Trace and mild mitral regurgitation, and trace aortic regurgitation are

considered physiologic in the absence of structural valve abnormalities.^[Ref]

Nervous system

• Very common (10% or more): Somnolence, sedation, and lethargy (26%)
• Common (1% to 10%): Ataxia, balance disorder, gait disturbance, hypotonia, falls, headache, status epilepticus, stereotypy, tremor^[Ref]

Metabolic

• Very common (10% or more): Decreased appetite (up to 49%), decreased weight (up to 13%)
• Common (1% to 10%): Dehydration, decreased blood glucose^[Ref]

This drug decreases appetite and causes dose-related weight loss. In clinical studies, decreased appetite and weight were reported in 37% and 9%, respectively (placebo=8% and 1%). Weight loss of 7% or greater from baseline was reported in 19% of patients treated with this drug compared to 2% of patients on placebo.^[Ref]

Psychiatric

• Common (1% to 10%): Abnormal behavior, insomnia, irritability, negativism
• Postmarketing reports: Aggression^[Ref]

Genitourinary

• Common (1% to 10%): Urinary incontinence, enuresis, urinary tract infection^[Ref]

Respiratory

• Very common (10% or more): Upper respiratory infections (up to 21%)
• Common (1% to 10%): Bronchitis, croup, rhinitis, laryngitis^[Ref]

Other

• Very common (10% or more): Fatigue, malaise, and asthenia (up to 30%), pyrexia (up to 21%)
• Common (1% to 10%): Chills, decreased activity, contusion, ear infection^[Ref]

Dermatologic

• Common (1% to 10%): Rash, eczema^[Ref]

Endocrine

• Common (1% to 10%): Blood prolactin increase^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (up to 31%), drooling and/or salivary hypersecretion (up to 13%)
• Common (1% to 10%): Constipation, gastroenteritis, vomiting^[Ref]

Musculoskeletal

• Common (1% to 10%): Hypotonia^[Ref]

Ocular

• Very common (10% or more): Glaucoma^[Ref]

Frequently asked questions

• How long does it take Fintepla to work?
• Is Fintepla a controlled substance?
• What type of epilepsy is Diacomit used to treat?
• How is Fintepla injected/administered?

Further information

Fenfluramine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer