Yes, excessive drowsiness or tiredness can occur with both Divaa 500 mg (divalproex sodium) and Lacosam 150 mg (lacosamide). These medicines act on the brain to control seizures, and one of their common side effects is sleepiness or reduced alertness. When taken together, these effects may become more noticeable in some people. The symptoms may be stronger if the dose is high, if the medicines were started recently, or if your body is more sensitive to them. Poor sleep, stress, alcohol use, or taking other sedative medicines may also increase drowsiness. Do not stop or reduce the medicines on your own, as this may increase the risk of seizures. It is important to discuss your symptoms with your doctor or neurologist. Your doctor may check whether the dosage needs adjustment, whether the timing of the medicines can be changed, or whether blood tests are needed to monitor drug levels and liver function. Please seek urgent medical help if you develop confusion, severe weakness, breathing difficulty, or worsening seizures while taking this medication.