IntroductionIn the United States (US), prophylactic treatment with the antiemetic trimethobenzamide has been used before initiating apomorphine therapy. However, US trimethobenzamide stores have been depleted, leaving uncertainty regarding whether antiemetic pretreatment is needed. MethodsThis modified Delphi panel aimed to inform circumstances when apomorphine is initiated without antiemetic pretreatment. During Round 1, a panel of 9 US movement disorder specialists rated the appropriateness of prescribing apomorphine therapy with and without antiemetic pretreatment across 192 patient scenarios and were able to review their scores in relation to other scores. During the Round 2, consensus was defined for each scenario as either strong (>75 % agreement) or moderate (66 % agreement). ResultsThere was strong consensus on 118 of 192 scenario’s (97 as appropriate and 21 as inappropriate), moderate consensus on 29 scenarios, some agreement on 32 scenarios, and lack of agreement on 13 scenarios. In the absence of an antiemetic, there was strong consensus that titration schedules should be flexible and based on dose response. However, the group only reached moderate consensus on the speed of titration, highlighting the need for more systematic information on this area. In the presence of an antiemetic, panelists considered usual initial dosing and flexible titration to be appropriate in most scenarios except for when the patient is already experiencing dopaminergic adverse events. ConclusionsExperts generally reached consensus that apomorphine can usually be prescribed without antiemetic pretreatment. Recommendations described here reflect the areas of greatest agreement among a panel of experts based on current available evidence.