Cochrane: Haloperidol
is one of the most frequently used antipsychotic drugs worldwide. It is
a first-generation antipsychotic drug. Haloperidol is highly effective
in treating the ‘positive symptoms’ of schizophrenia, such as hearing
voices, seeing things and having strange beliefs. However, haloperidol
also has serious side effects such as involuntary shaking, blurred
vision, having a dry mouth and causing strange postures.
Psychiatrists
and people with schizophrenia often face a trade-off between protection
against mental illness and coping with these severe side effects.
Previous small studies and unsystematic reviews have found no
difference between the various first- generation antipsychotic drugs.
This has led to the assumption that these drugs are similar in effectiveness (despite observations by psychiatrists and health professionals that these drugs do sometimes differ in their effectiveness and side effects). Because of high prescription-rates, research on haloperidol is very important.
A search for randomised trials was run in 2012. This review
includes 63 trials with 3675 participants. Haloperidol was compared
with a large number of other first-generation antipsychotic drugs
(including bromperidol, loxapine and trifluoperazine) to assess its effectiveness, acceptability and tolerability. The findings of the review
support the evidence of previous small, narrative studies and
unsystematic reviews. There was no difference between haloperidol and
other mainly high-potency first-generation antipsychotic drugs. In
addition, haloperidol was characterised by a similar risk
profile and side effects to other first-generation antipsychotic drugs.
People receiving haloperidol were less likely to experience akathisia
in the medium term. Occurrence of other specific side effect such as
tremor, dystonia, dyskinesia and rigor were all similar between
treatment groups. Psychiatrists and people with schizophrenia should
know that haloperidol and other first-generation antipsychotic drugs are
similar in their effectiveness and risk of side effects. These drugs should also be similar in their acceptability for people with schizophrenia.
However, results were limited due to the low quality of many of the
included studies and low quality of evidence provided. Future studies of
higher quality are required.