Which antipsychotic has maximum hypotensive side effect?

Ref: Goodman 3 Gill man. The pharmacological basis of therapeutics, 12'" edition, Pg No. 440 Basic and clinical Pharmacology by Betram Katzitng, 12th edition Pg No 508Explanation:Phenothiazines are classified into three groups: a. Aliphatic derivatives- Chlorpromazine h. Piperedine derivative- Thioradazine c. Piperazine derivative- Trifluoperazine, Perphenazine, fluphenazineAmong the above three, a & b are less potent and having more affinity for alpha 1 receptor and hence can cause more hypotensionPiperazine is pore potent typical and less affinity for alpha I receptor, hence less hypotensionButerophenones are the potent typical antipsychotic (haioperidol) having highest Extrapyramidal effects