 Elimination half life varies widely between individuals and is about 5 to 15 hours after a single dose, and 18 to 19 days on average when given daily.Flunarizine is a diphenylmethylpiperazine derivative related to the antihistamine hydroxyzine.Flunarizine may help to reduce the severity and duration of attacks of paralysis associated with the more serious form of alternating hemiplegia, as well as being effective in rapid onset dystonia-parkinsonism (RDP).