This study aims to evaluate the effectiveness of the “Action and Coping Plans for Medication Adherence Intervention - ADHERE” in promoting medication adherence in patients with myocardial infarction followed up in primary health care units and using cardioprotective medications. This is a randomized clinical trial with two groups and blinding of the evaluator. The enrolled participants who agree to participate in the study by signing the Free and Informed Consent Form (FICF) will be randomly distributed into the study, intervention and control groups using a random block randomization scheme. For the participants in the intervention group, three meetings will be held: at T0 (baseline), sociodemographic and clinical characterization data will be collected, as well as psychosocial measures, global assessment of medication adherence, in addition to blood pressure measurements, peripheral pulse rate and laboratory tests to assess the lipid profile. Afterwards, the ADHERE intervention strategy will be applied to participants with positive intention, which consists of developing action plans and addressing barriers to adherence to cardioprotective medications. In T1 (30 days after T0), participants will receive face-to-face reinforcement. In T2 (60 days after T0), another researcher will repeat the same measures as in T0 and acceptability will be assessed through a debriefing to assess participants' perception of the intervention. Feasibility will be assessed by the number of invited participants who showed interest in participating, the number of eligible and ineligible people recruited and the reasons for ineligibility, the number of eligible participants who withdrew from participating and the reasons for withdrawal, in addition to the time spent applying the intervention. Participants in the control group, after agreeing to participate in the research, will undergo tree meetings, T0 (baseline) for collecting sociodemographic and clinical data in addition to other measures as in the intervention group. In T1 (30 days after T0) they will receive the usual care of the unit and will be scheduled to return after 60 days, T2 (60 days after T0), where the same measurements will be collected as in the first contact. The description of the qualitative variables will be done by calculating frequencies and percentages. And for the quantitative variables, measures of central tendency and dispersion will be calculated. A significance level of 5% will be adopted. The findings of this study may provide a nursing intervention with evidence of effectiveness, feasibility and acceptability; these results provided support for the intervention to be tested in a real context in the future.