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Comparative Efficacy and Tolerability of Benzatropine and Terazosin in the Treatment of Hypersalivation Secondary to Clozapine

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Abstract

Objective: In this open-label, non-randomised, 12-week, retrospective comparative study, the efficacy and tolerability of benzatropine (benztropine) and terazosin were assessed in patients diagnosed with schizophrenia or a related psychotic disorder who were treated with clozapine and subsequently began to experience hypersalivation within 1 month.

Methods: Sixty clinic charts were reviewed. All patients were from long-term care facilities. Patients were randomly assigned to four treatment groups: (a) no treatment; (b) treatment with benzatropine 1mg twice daily; (c) treatment with terazosin 2mg once daily, at night-time; and (d) treatment with benzatropine and terazosin according to the same scheme as in (b) and (c). Clozapine dosages in these four groups were 100mg to 700mg daily (average 325mg daily). The primary target symptom (hypersalivation) was assessed and recorded by open questioning at baseline and at weeks 1, 4 and 12.

Results: The primary efficacy end-point was a comparison of the change of hypersalivation in patients’ response in the four treatment groups from baseline to week 12. All the changes were statistically significant (p < 0.001). However, treatment with benzatropine and terazosin together was more effective. Use of this combined therapy in the management of hypersalivation resulted in a 100% satisfactory response vs 66.7% of patients on benzatropine, and 93.3% of patients on terazosin. Compliance with medication was 100% and no significant adverse events were observed. The most common adverse events reported by patients were constipation, dizziness and drowsiness. However, these did not present a valid reason for discontinuation of the benzatropine and terazosin therapy during clozapine-induced hypersalivation.

Conclusion: The results of this retrospective study demonstrated that terazosin was an effective and well tolerated drug in the management of a very common adverse effect of clozapine therapy, namely, hypersalivation. The combination of benzatropine and terazosin provided consistently superior response rates to either therapy alone.

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Authors and Affiliations

  1. Clinical Research Department, Forest Foundation Inc., 4755 North Kenmore Avenue, Chicago, Illinois, 60640, USA

    Michael J. Reinstein, Larissa A. Sirotovskaya, Maxim A. Chasanov, Lynne E. Jones & Sangarapillai Mohan

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  1. Michael J. Reinstein
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  2. Larissa A. Sirotovskaya
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  3. Maxim A. Chasanov
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  4. Lynne E. Jones
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  5. Sangarapillai Mohan
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Reinstein, M.J., Sirotovskaya, L.A., Chasanov, M.A. et al. Comparative Efficacy and Tolerability of Benzatropine and Terazosin in the Treatment of Hypersalivation Secondary to Clozapine. Clin. Drug Investig. 17, 97–102 (1999). https://doi.org/10.2165/00044011-199917020-00003

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  • DOI: https://doi.org/10.2165/00044011-199917020-00003

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