September 06, 2004

Haldol in first episode schizophrenia: low vs high dose

Oosthuizen P, Emsley R, Turner HJ, Keyter N. A randomized, controlled comparison of the efficacy and tolerability of low and high doses of haloperidol in the treatment of first-episode psychosis The International Journal of Neuropsychopharmacology (2004), 7:125,131

This study was conducted to determine which of two doses of haloperidol (Haldol) would be more effective for patients who are new to schizophrenia. In America, we are quick to go to second generation antipsychotics like Risperdal or Zyprexa, but outside of the US, Haldol is still used frequently because of its cost effectiveness and its high potency. People often stay away from Haldol because of the greater risk for side effects like tardive dyskinesia (a movement disorder) and other long term side effects. Also, since Haldol is older and off patent, it is not marketed and can sometimes be forgotten. There are some who argue that the new antipsychotics are only marginal improvements and therefore we are quick to ignore Haldol. Anyways, regardless of the debate, these authors wanted to know if a higher dose of Haldol was better to give or if it would be just as effective but more likely to give side effects.

The authors chose to compare a 2mg per day of Haldol group versus an 8 mg per day group. They came up with those doses based on previous data that suggested that 8 mg was a threshold dose for the initiation of side effects. The authors ultimately found that 2mg and 8mg were equally effective but that the 8mg group did have some higher side effects. One side effect was an increase in prolactin (a hormone that is involved in production of breast milk and in growing breast tissue.) They also showed that both groups had movement disorders (called EPS or parkinsonian movments) but that 8mg was worse than 2mg. They also thought that the 2mg did marginally better on negative symptoms than did the 8mg group.

Overall, this study is interesting because in many situations it is worthwhile, though debatable, to consider starting with Haldol first when someone has new symptoms requiring treatment with an antipsychotic. While it is probably better to try a 2nd generation antipsychotic first when available one can see treatment effects from Haldol. It would be better based on these data to start at 2mg per day than a higher dose though individuals vary such that it may be necessary to start at 5mg daily or higher doses if the psychotic symptoms don't remit. If you or someone you know is on Haldol, you should not consider changing the dose based on this study but if you have questions you can ask your doctor.

This study was supported by the Medical Research Council of South Africa.

Click here to link to the article on Pubmed

Author: Jacob Ballon


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