Myalept Side Effects

Generic name: metreleptin

Medically reviewed by Drugs.com. Last updated on Feb 20, 2025.

Note: This document provides detailed information about Myalept Side Effects associated with metreleptin. Some dosage forms listed on this page may not apply specifically to the brand name Myalept.

Applies to metreleptin: subcutaneous powder for solution.

Precautions

It is very important that your doctor check your or your child's progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Some patients who use this medicine may make antibodies in their blood which may reduce how well this medicine or the leptin in the body works. This may lead to side effects such as infection, diabetes, or an increase in the amount of fat in the blood. Tell your doctor right away if you or your child have these side effects while receiving this medicine.

Using this medicine may increase your risk of getting lymphoma (cancer of the lymph system). Talk to your doctor if you or your child have concerns about this risk.

Hypoglycemia (low blood sugar) may occur when this medicine is used together with insulin or a diabetes medicine. Symptoms of low blood sugar must be treated before they lead to unconsciousness (passing out). Different people may feel different symptoms of low blood sugar. It is important that you learn which symptoms of low blood sugar you usually have so that you can treat it quickly.

Symptoms of low blood sugar include anxiety, behavior change similar to being drunk, blurred vision, cold sweats, confusion, depression, difficulty in thinking, dizziness or lightheadedness, drowsiness, excessive hunger, fast heartbeat, headache, irritability or abnormal behavior, nervousness, nightmares, restless sleep, shakiness, slurred speech, and tingling in the hands, feet, lips, or tongue.

If symptoms of low blood sugar occur, eat glucose tablets or gel to relieve the symptoms. Also, check your blood for low blood sugar. Get to a doctor or a hospital right away if the symptoms do not improve. Someone should call for emergency help immediately if severe symptoms such as seizures or unconsciousness occur . Have a glucagon kit available, along with a syringe and needle, and know how to use it. Members of your household also should know how to use it.

If you or your child develop a skin rash, hives, or any allergic reaction (including anaphylaxis) to this medicine, check with your doctor as soon as possible.

Do not stop using this medicine suddenly without checking first with your doctor. You may need to slowly decrease your dose before stopping it completely.

This medicine mixed with bacteriostatic water for injection (BWFI) contains benzyl alcohol, which may cause serious reactions in premature or low-birth-weight infants. Sterile water for injection (WFI) is recommended for use in newborn and premature infants. Discuss this with your doctor if you are concerned.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Serious side effects of Myalept

Along with its needed effects, metreleptin (the active ingredient contained in Myalept) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking metreleptin:

Other side effects of Myalept

Some side effects of metreleptin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to metreleptin: subcutaneous powder for injection.

General adverse events

The most frequently reported side effects were headache, hypoglycemia, decreased weight, and abdominal pain.^[Ref]

Metabolic

• Very common (10% or more): Hypoglycemia (13%), decreased weight (13%)^[Ref]

Nervous system

• Very common (10% or more): Headache (13%)
• Common (1% to 10%): Dizziness, paresthesia^[Ref]

Gastrointestinal

• Very common (10% or more): Abdominal pain (10%)
• Common (1% to 10%): Nausea, diarrhea, pancreatitis^[Ref]

It has been reported that two patients (4%) had symptoms of pancreatitis. Both had a medical history of pancreatitis.^[Ref]

Immunologic

• Frequency not reported: Autoimmune disorder, immunogenicity^[Ref]

In vitro neutralizing activity anti-metreleptin antibodies were identified in 2 patients (n=33) with generalized lipodystrophy who showed severe infections and worsening metabolic control (increases in HbA1c and/or triglycerides). Three patients with anti-metreleptin antibodies without lipodystrophy showed excessive weight gain, and/or development of glucose intolerance or diabetes.

In clinical trials, anti-metreleptin antibodies were detected in 36 of 43 generalized lipodystrophy patients, with titers ranging from 1:5 to 1:1,953, 125; however, these numbers may be misleading as detection of antibody formation is highly dependent on the sensitivity and specificity of the assay (the assays utilized in clinical trials lacked sensitivity), handling of the sample, concomitant drugs, and underlying disease. Due to incompleteness of the immunogenicity data, the clinical significance and the magnitude and persistence of the anti-drug responses are not well characterized.^[Ref]

Genitourinary

• Common (1% to 10%): Ovarian cyst

Hematologic

• Common (1% to 10%): Anemia^[Ref]

Hypersensitivity

• Common (1% to 10%): Injection-site erythema, urticaria
• Frequency not reported: Generalized rash^[Ref]

Musculoskeletal

• Common (1% to 10%): Arthralgia, back pain^[Ref]

Other

• Common (1% to 10%): Pyrexia, ear infection, fatigue^[Ref]

Renal

• Common (1% to 10%): Proteinuria^[Ref]

Respiratory

• Common (1% to 10%): Upper respiratory tract infection^[Ref]

Oncologic

• Frequency not reported: T-cell lymphoma, anaplastic large cell lymphoma

Three cases of T-cell lymphoma were reported among patients with acquired generalized lipodystrophy; 2 patients diagnosed with peripheral T-cell lymphoma during treatment had immunodeficiency and significant hematologic abnormalities including severe bone marrow abnormalities prior to starting treatment. Anaplastic large cell lymphoma was reported in 1 patient receiving this drug who did not have hematologic abnormalities before treatment.

See also:

Further information

Myalept 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.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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