BackgroundPatients’ knowledge on prescribed medications play a key role in the long term management of cardiac diseases and in determining their outcome. The present study evaluates the knowledge about prescribed medication among cardiac patients and aim to identify factors influencing knowledge.MethodsA descriptive-cross-sectional study was conducted among 200 adult patients attending clinics at the Cardiology Unit of the National Hospital of Sri Lanka. Knowledge assessment focused on four different sections; drug name, dose, frequency and indication. The total score of 60 was calculated by giving each component the following weighted scores; drug name = 20, indication = 20, drug dose = 10 and frequency = 10. A binary logistic regression analysis to evaluate factors associated with ‘good knowledge’ (total score ≥ 40) was performed.ResultsAmong 200 participants 56.5% (n = 113) were males. Mean age was 59.7 ± 8.2 years and a majority (n = 170, 85.0%) were older than 50 years of age. Sinhala was the primary language of 91.5% (n = 183) of participants, while English was the primary language in only two of the study participants (1.0%). Eighty four percent of the participants were educated up to secondary education or above, while 2.5% (n = 5) had no formal education. The overall knowledge (total score-60) on prescribed medications among the study population was ‘poor’ (score ≤ 20) in 46%, ‘adequate’ (score 21–40) in 36.5% and ‘good’ (score ≥ 40) in 17.5%. The results of the binary logistic regression analysis indicates that Secondary (OR-1.53) and Tertiary levels (OR-2.79) of education, self-reported perception of illness as being Moderate (OR-1.23) or Severe (OR-1.70) and being educated by a doctor (as reported by patients) (OR-1.69) significantly increased the odds of having a ‘Good Knowledge of Drugs’. Majority of the patients were unable to read and understand the information written in English. The doctor’s contributed towards educating on drug information only in 33.0% of the patients.ConclusionIn a resource-poor setting in patients with Limited English Proficiency, lower level of education and misperception of illness severity resulted in reduced knowledge on prescribed medications. Furthermore, being educated by a doctor significantly improved knowledge. However the doctors’ contribution at present to deliver quality health information to their patients was at an unsatisfactory level.