Ziprasidone (brand name Geodon) is an atypical antipsychotic drug developed by Pfizer, and used for treating both the negative and positive symptoms of schizophrenia and schizoaffective disorder. It was approved by the FDA in 2001, the fifth atypical antipsychotic to be approved for use. It is a benzothiazolylpiperazine with chemical formula C21H21ClN4OS.

The effective dosage range is between 80 and 160 mg/day. Ziprasidone is also quite possibly effective as an antidepressant and anxiolytic. It works as both a dopamine and serotonin antagonist, and has very little anticholinergic activity. It is a strong 5-HT2A antagonist, and has high affinity for the 5-HT1A, 5-HT1D, and 5-HT2C receptor subtypes. It is a 5-HT1A agonist, unlike Olanzapine and Clozapine.

Ziprasidone has less negative effects on cognitive ability compared to Olanzapine, as well as less extrapyramidal symptoms. The most common side effects are fatigue, nausea, constipation, dizziness, restlessness, diarrhea, rash, cough and runny nose, tremor, shuffling, and uncontrollable movements.

Chemical structure:

                            H   H
                             \ /
                      H      ,C  O
                       \    /  \//
                        C==C    C
                       /    \   |
               H  H   C      C--N
                \  \ /\\    //   \
          H   H  C--C   C--C      H
           \ /  / \  \  |   \
        H   C--N   H  H Cl   H
         \ /    \
   H   H--C      C--H
    \      \    / \
 H   C      N--C   H
  \ / \\   /   |\
   C   C--C    H H
   ||  |  \\
   C   C   N
  / \ //\ /
 H   C   S