My 19 yr old just wont take medication

My son is 19 now and has had epilepsy from the age of 14 just hes a nightmare to get him to take his tablets now as hes classed as an adult hes having regular more violent seizures now and he also breath holds in his seizures lm really worried l know its a thing most go through were they dont want to take medication as his dad also has epilepsy and started at the same age he did the same thing at his age but its still scary
Anyone any advice