Orlistat is to be used only in patients with body mass index (BMI) of at least 30kg/m2 that too with concurrent diet control. The drug should be discontinued if the 5% of initial weight is not lost. Its side effects may include palpitations, increased blood pressure, constipation, dry mouth, nausea, haemorrhoid (piles) aggravation, anxiety, insomnia, light-headedness, headache, paraesthesia, sweating, taste perversion, depression, psychosis, mania, anger, suicidal ideation, suicide, abnormal dreams, abnormal gait, amnesia, impaired concentration, confusion, mood changes, nightmares, short term memory loss, speech disorder, transient ischaemic attack, cerebrovascular accident (stroke), tremor, twitch, vertigo, serotonin syndrome neuroleptic malignant syndrome (NMS).