Community preferences for novel, user-friendly primaquine packaging and paediatric formulations for Plasmodium vivax radical cure — a qualitative study from the Thai-Myanmar border and Cambodia

Background Successful radical cure of Plasmodium vivax is critical to achieve malaria elimination. Primaquine, a highly effective 8-aminoquinoline, faces significant challenges due to its long treatment course, bitter taste, lack of child-friendly formulations, suboptimal packaging, and limited community understanding of its benefits. This study explored treatment-seeking behaviour, adherence, packaging and flavoured primaquine paediatric formulations in vivax-affected communities in Cambodia and on the Thai-Myanmar border. Methods Between October and December 2024, 43 community members and health workers participated in a total of eight focus group discussions. Audio-recordings were transcribed, translated into English and analysed thematically using qualitative data management software, NVivo 15 (Lumivero, USA). Results Many febrile patients began with 1–3 days of self-care at home using simple remedies like paracetamol, but formal care was usually sought when symptoms persisted, especially for children. Despite motivation to complete treatment, adherence was challenged by forgetfulness, symptom resolution, bitter taste and tablet deterioration (e.g. difficulty keeping pills dry in field settings). Participants reported a preference for packaging with local language instructions, pictograms, and visual aids such as checkboxes and calendars. They viewed complete blister packs in boxes with inserts as more trustworthy than loose tablets. Administering adult tablets to children posed major challenges; the bitter taste of primaquine often caused children to refuse or spit out doses, and difficulties in cutting, crushing and mixing adult tablets were burdensome and led to dosing errors. To improve acceptability, caregivers preferred child-friendly formulations, especially sweet, fruit-flavoured syrups for young children and chewable, candy-like tablets for older children. Conclusion Participants highlighted specific adherence challenges and offered practical solutions, highlighting easily-implementable adherence-supportive packaging and palatable paediatric formulations, informed by community preferences. Our findings offer a practical roadmap to improve adherence and support P. vivax elimination efforts.