Lorcaserin Side Effects

In clinical studies on lorcaserin, many people reported side effects such as back pain, symptoms of the common cold, and urinary tract infections. Fortunately, most reactions to this drug are not serious and can be treated easily. Some side effects, however, are serious and may need immediate treatment. Seek immediate medical care if you are taking this drug and experience fainting, enlarged breasts, or a racing heartbeat.

An Introduction to Side Effects of Lorcaserin

Just like any medicine, lorcaserin (Belviq®) can cause side effects. However, not everyone who takes the medication will have problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are treated easily by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with lorcaserin. Your healthcare provider can discuss a more complete list with you.)

Serious Lorcaserin Side Effects

Some side effects of lorcaserin are potentially serious and should be reported immediately to your healthcare provider. These include but are not limited to:
  • Signs of serotonin syndrome (a rare but dangerous problem associated with medications that affect serotonin), such as:
    • Chills
    • Tremor
    • Confusion, agitation, or other mental changes
    • Feeling disoriented
    • Restlessness
    • Muscle twitching, spasms, or stiffness
    • Problems with coordination
    • Fever or excessive sweating
    • A rapid or racing heartbeat
    • High or low blood pressure
    • Nausea, vomiting, or diarrhea
  • Signs of low blood sugar levels, such as:
    • Confusion or abnormal behavior
    • Blurred vision
    • Shakiness
    • Anxiety
    • Sweating
    • Fainting
  • Problems with your memory, attention, or concentration
  • Changes in mood, including depression or an abnormally heightened mood
  • Thoughts of suicide or of harming yourself
  • Feeling outside of your body (disassociation)
  • Hallucinations (seeing or hearing things that are not really there)
  • Difficulty breathing
  • Shortness of breath or lightheadedness
  • Swelling of the arms, legs, ankles, or feet
  • A slow, fast, racing, or irregular heartbeat
  • Extreme fatigue or weakness
  • An erection that lasts more than four hours
  • Signs of infection, such as:
  • Unusual fatigue or tiredness
  • Enlarged breasts or a milky discharge from your breasts
  • Signs of an allergic reaction, such as:
    • An unexplained rash
    • Hives
    • Itching
    • Swelling of the mouth or throat
    • Wheezing
    • Difficulty breathing.

More Headlines in Lorcaserin Side Effects

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‣ Final Thoughts
Last reviewed by: Kristi Monson, PharmD
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