Is it safe to take amitripyline 20mg, sertraline 100mg & piriton at the same time piriton& what effects could they cause?

Sedation. Piriton is an antihistamine that can be sedating -- making you sleepy. Combined with amitriptylene, even more so. If you're going to use them, i'd suggest spreading them out and not taking all at once -- unless you're planning to go to sleep.