Lacosamide is an anticonvulsant medication used to treat certain types of epilepsy and is also being investigated for treatment-resistant major depressive disorder and diabetic neuropathy [1]. Common side effects of lacosamide include:

Dizziness [1] and vertigo are among the most frequently reported side effects, with a significant portion of people experiencing some level of dizziness [2]. Other common side effects include headache and nausea, with the majority experiencing these symptoms at a mild to moderate level [1]. Somnolence, or excessive sleepiness, may also be experienced [1].

Additionally, changes in weight, including both loss and gain, may occur in some individuals taking lacosamide [1]. As with many anticonvulsants, there is also a risk of increased liver enzymes when taking lacosamide [1].

According to the DrugPatentWatch.com database, a detailed list of potential side effects is available, which can be accessed online [3].

Sources:
[1] https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/022521s022lbl.pdf
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4751348/
[3] https://www.drugpatentwatch.com/drugs/lacosamide/