The impact of tobacco smoking in patients taking long-action injection drugs – A retrospective comparative study between haloperidol and risperidone

Abstract

Introduction

Smoking rate seems to be higher among patients with schizophrenia, comparing to other psychiatric entities, mainly in those who are on typical antipsychotics. Tobacco is known to have enzyme inducer properties, due to cytochrome P450 complex activity: CYP1A1, CYP1A2, CYP2E1 and CYP2D6. CYP2D6 and CYP1A2 play an important role in antipsychotics metabolism, mainly in the first generation ones, like haloperidol, despite its importance in risperidone metabolism.

Aim

To analyze the importance of tobacco smoking in patients taking long-action injections.

Objectives

To investigate how sexual dysfunction varies with tobacco smoking, in patients taking long-action injections.

Methods

Individuals from both sexes, from 18 to 55 years old, taking antipsychotic long-action injections, answered the Arizona Sexual Experience Scale (ASEX).

Results

In the studied population (n = 44), there were 20 individuals on haloperidol and 24 individuals on risperidone. In a total of 18 (40.9%) positive results for sexual dysfunction, 6 were on haloperidol (30%), 12 (50%) were on risperidone. Seventeen individuals of the 20 who were on haloperidol were smokers, but only 4 were considered to have sexual dysfunction, 35.3%; 12 of the 24 individuals who were on risperidone were smokers, but only 5 were considered to have sexual dysfunction, 41.7%.

Conclusions

Patients treated with haloperidol smoke more, comparing to risperidone. Sexual dysfunction is more frequent in patients taking risperidone than in patients taking haloperidol. This data supports that CYP2D6-CYP1A2 induction by tobacco, mainly interacts with haloperidol, which may be helpful for patients to try less side effects.

Disclosure of interest

The authors have not supplied their declaration of competing interest.