What Are the Side Effects of Taking Belviq?

Common side effects of Belviq, or lorcaserin, include anxiety, blurred vision, chills, painful urination and ear congestion, according to Drugs.com. Patients may also experience a faster heart beat, headaches and nausea. Less common side effects include increased urge to urinate, dry mouth, swollen glands and joint pain.

Neurological side effects of Belviq are dizziness, headaches and disorientation, notes Drugs.com. Hypertension is a common cardiovascular side effect, while anxiety, insomnia and depression are common psychiatric side effects. Patients may also experience endocrine side effects, such as hypoglycemia, and hematologic side effects, such as reduced hemoglobin and reduced lymphocyte levels.

A common respiratory side effect is infection of the upper respiratory tract, reports Drugs.com. General side effects include nausea, chills, headaches, dizziness and fatigue. Dermatological side effects include rashes, while a common genitourinary side effects is urinary tract infection. Patients may also experience back pain and decreased appetite. Nondiabetic patients may experience blurred vision and visual impairment, while diabetic patients may complain of irritations, inflammation and cataract conditions.

Side effects such as hives, difficulty breathing and a swollen face may indicate an allergic reaction, states RxList. Serious side effects that demand medical attention include hallucinations, high fever, stiff muscles, rapid heart rate and shortness of breath. Some male patients report painful erections that last more than four hours, notes WebMD. If this happens, the patient should stop taking Belviq and seek medical attention immediately to prevent permanent damage.