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Lorcaserin

Generic Name: lorcaserin (lor KAS er in)
Brand Name: Belviq, Belviq XR

Medically reviewed by Drugs.com on Jan 22, 2020 – Written by Cerner Multum

What is lorcaserin?

Lorcaserin is used together with diet and exercise to treat obesity. Lorcaserin affects appetite signals in the brain, helping you feel full with smaller meals.

Lorcaserin is sometimes used to treat obesity that may be related to diabetes, high cholesterol, or high blood pressure.

Lorcaserin will not treat any underlying health condition (such as heart disease, diabetes, high blood pressure). Keep taking any other medications your doctor has prescribed to treat these conditions.

Lorcaserin may also be used for purposes not listed in this medication guide.

Important Information

Do not use lorcaserin if you are pregnant. Weight loss during pregnancy can harm an unborn baby.

Serious drug interactions can occur when certain medicines are used together with lorcaserin. Tell each of your healthcare providers about all medicines you use now, and any medicine you start or stop using.

Before taking this medicine

You should not use lorcaserin if you are allergic to it.

Do not use lorcaserin if you are pregnant. Weight loss during pregnancy can harm an unborn baby, even if you are overweight. Tell your doctor right away if you become pregnant during treatment.

Tell your doctor if you have ever had:

In clinical studies, more people taking lorcaserin were diagnosed with cancer compared with people taking an inactive placebo. It is not clear whether lorcaserin actually causes cancer. Talk to your doctor about your own cancer risk while taking lorcaserin.

You should not breastfeed while using lorcaserin.

Lorcaserin is not approved for use by anyone younger than 18 years old.

How should I take lorcaserin?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

The regular tablet is usually taken 2 times per day. The extended-release tablet is taken only once per day. Follow your doctor's instructions.

Swallow the extended-release tablet whole and do not crush, chew, or break it.

You may take lorcaserin with or without food.

You should lose at least 5% of your starting weight during the first 12 weeks of taking lorcaserin and eating a low calorie diet. Call your doctor if you do not lose at least 5% of your starting weight after taking the medicine for 12 weeks.

Lorcaserin is only part of a complete program of treatment that also includes diet, exercise, weight control, and possibly testing your blood sugar. Follow your diet, medication, and exercise routines very closely.

Do not share lorcaserin with another person. Keep the medication in a place where others cannot get to it.

Store at room temperature away from moisture and heat. Keep track of your medicine. You should be aware if anyone is using it improperly or without a prescription.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking lorcaserin?

Avoid driving or hazardous activity until you know how lorcaserin will affect you. Your reactions could be impaired.

Avoid taking cough and cold or allergy medications while taking lorcaserin.

Do not take any other prescription or over-the-counter weight-loss products without your doctor's advice.

Lorcaserin side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using lorcaserin and call your doctor at once if you have:

  • unusual changes in mood or behavior, thoughts of suicide or hurting yourself;

  • dry eyes, blurred vision;

  • feelings of standing next to yourself or being outside of your body;

  • memory problems, trouble concentrating;

  • breast swelling (in women or men), nipple discharge;

  • penis erection that is painful or lasts longer than 4 hours;

  • heart problems--fast heart rate, trouble breathing, dizziness, ongoing weakness, or swelling in your arms, hands, legs, or feet;

  • high levels of serotonin in the body--agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting; or

  • severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Lorcaserin dosing information

Usual Adult Dose for Weight Loss:

10 mg orally twice per day

Comments: Response to therapy should be evaluated by week 12. If a patient has not lost at least 5% of baseline body weight, discontinue this drug as it is unlikely the patient will achieve and sustain clinically meaningful weight loss with continued treatment.

Use: Adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in patients with an initial body mass index (BMI) of 30 kg/m2 or greater (obese) OR 27 kg/m2 or greater (overweight) in the presence of at least one weight-related comorbidity such as hypertension, type 2 diabetes mellitus, or dyslipidemia.

What other drugs will affect lorcaserin?

Tell your doctor about all your current medicines. Many drugs can affect lorcaserin, especially:

This list is not complete and many other drugs may affect lorcaserin. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.