Introduction: Hypertension is the most common non-communicable disease, which persists as a major risk factor of cardiovascular diseases such as stroke, myocardial infection, and heart failure. Another major problem in clinical practice was the patients' adherence to treatment, directly related to the number of hypertension pills to be taken. Thus, determining the appropriate time duration and action of a hypertensive drug to maintain the blood pressure is needed. Olmesartan is one of the drug compounds frequently used for long-acting anti-hypertensive treatment. It is often combined with amlodipine; however, their combination remains unclear to provide equal efficacy and safety. Thus, in this article, authors systematically summarize the combination of Olmesartan with amlodipine.

Methods: This systematic literature review was extracted from Science Direct and Pubmed to identify randomized clinical trials (RCT) of the outcome of the Olmesartan/amlodipine effect compared with other hypertension regimens by using PRISMA guideline 2009. The methodological quality of the included studies was assessed independently by two reviewers using The Cochrane Collaboration's RoB 2 tool.

Results: Authors evaluated twelve studies in the last ten years, and there were four studies with an intention-to-treat protocol (25% of articles had some concern, and 75% had a low risk of bias.) and eight studies with per-protocol analysis (37,5% of articles were concerned, and the rest had a low risk of overall bias). Authors also presented the efficacy and safety outcomes of the study reviewed.

Conclusion: Hypertension is a common non-communicable disease, and treatment approaches for hypertension vary widely. Administration of combination drugs is a good approach in reducing the dose of drug administration and reducing the incidence of side effects in monotherapy. Inhibiting the RAA system by olmesartan and reducing vascular smooth muscle tone by amlodipine gives better results and can be a safe and effective option for lowering blood pressure in hypertensive patients. The side effects observed were not severe and only observed in a few cases, making it an option to treat hypertension.