The blended learning material of gastrointestinal (GI) pharmacotherapy was noted by students as needed improvement. As pharmacology is the core component of pharmacotherapy, it was hypothesised that improved students engagement with online learning of GI pharmacology will engage and motivate students in the learning of GI pharmacotherapy. Constructivist learning, guided by a student-centred approach, was used to design an online GI pharmacology-predominant module containing some pharmacotherapy learning activities. Students' perception of the usefulness of the module was evaluated by survey, which consisted of 7 multiple-choice items in Likert-scale format and 4 open-ended questions. Twenty seven students participated in the study, recorded a 36% response rate. Majority of the students were satisfied with the module indicating it has improved learning effectiveness, learning efficiency, and self-efficacy. Students were engaged and motivated to learn from the module as evidenced from their active participation in the learning activities presented, including the discussion forums of pharmacotherapy case studies. This study demonstrated a creative approach of using students' feedback in guiding the implementation of a constructivist framework in the design of an online pharmacology module for pharmacy students. The range of interactive learning activities detailed the various strategies of constructivism, something that was not explicitly described in the literature. The findings uphold the hypotheses of the study, and provided evidence that improved effectiveness of blended learning of pharmacology contributed to improved learning experience of pharmacotherapy.