Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Adverse effects
Systematic review	511 people 7 RCTs in this analysis	Use of antiparkinsonian drugs 4 to 10 weeks 84/253 (33%) with sulpiride 115/258 (45%) with first-generation antipsychotic drugs	RR 0.73 95% CI 0.59 to 0.90	Small effect size	sulpiride