The Quser XL 400 Tablet can be taken with or without food However it is recommended to take it at the same time every day to maintain a consistent level of medication in the body Follow the prescribed dose and duration as advised by your doctor and if you miss a dose take it as soon as you remember It is important not to stop this medication suddenly without consulting your doctor as it could potentially worsen your symptoms However discontinue this medicine immediately if you experience symptoms of Neuroleptic malignant syndrome NMS such as fever muscle rigidity altered consciousness or seizures Common side effects of this medicine may include headaches dry mouth and constipation In the beginning this medication may cause a sudden drop in blood pressure when changing positions so it is advisable to rise slowly if you have been sitting or lying down It may also cause dizziness and drowsiness so refrain from driving or performing activities that require mental focus until you know how this medicine affects you This medication may lead to weight gain but adopting a healthy diet and exercising regularly can help reduce this side effect Be cautious while using this medicine as it may increase the risk of developing diabetes Therefore it is recommended to monitor your glucose levels regularly Inform your doctor if you experience any unusual changes in mood or behavior new or worsening depression or have suicidal thoughts while taking this medicine