Fensant 100mg Injection is used to treat and prevent epilepsy (seizures). It controls seizures by decreasing the abnormal and excessive activity of the nerve cells in the brain. It is given when this medicine cannot be given orally, such as in hospitalized patients. Fensant 100mg Injection is given under the supervision of a healthcare professional and should not be self-administered. It is advisable to take it at the same time each day as this helps to maintain a constant level of medicine in the body. If you have missed a dose, take it as soon as you remember it. You should finish the full course of treatment even if you feel better as stopping the medication without talking to your doctor may cause non-stop seizures (called status epilepticus), which can be life-threatening. The most common side effects of this medicine include skin rashes, headache, feeling or being sick, difficulty sleeping, dizziness, and feeling sleepy or drowsy. Additionally, you may notice some injection site reactions like redness or swelling. Most side effects wear off, but if they bother you or do not go away, tell your doctor. There may be ways of preventing or reducing these effects. Before taking this medicine, tell your doctor if you have kidney or liver problems, meningitis or depression, or suicidal thoughts. Also let your healthcare team know about all other medications you are using as some may affect, or be affected by, this medicine, including contraceptive pills. If you are pregnant or breastfeeding, the dose may be adjusted. You should avoid driving or riding a bicycle if this medicine makes you drowsy or dizzy. You may need frequent blood tests to check how you are responding to this medicine.