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Lorcaserin

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

Medically reviewed on November 13, 2017.

What is lorcaserin?

Lorcaserin affects chemical signals in the brain that control appetite. Lorcaserin works by helping you feel full with smaller meals.

Lorcaserin is used together with diet and exercise to treat obesity.

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.

To make sure lorcaserin is safe for you, tell your doctor if you have:

It is not known whether lorcaserin passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

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. Do not take this medicine in larger or smaller amounts or for longer than recommended.

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.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

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.

Store at room temperature away from moisture and heat.

Keep track of the amount of medicine used from each new bottle. Lorcaserin is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.

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

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

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?

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

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

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

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.

See also: Side effects (in more detail)

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 and any you start or stop using, especially:

This list is not complete. Other drugs may interact with lorcaserin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

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.

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