Trends in Antihypertensive Combination Therapy

Specific combinations of 2 drug classes, based upon complimentary mechanisms or benefits for a concomitant disease, are recommended for the management of hypertension. However, how often these combinations are utilized and how these trends are affected by the effectiveness of blood pressure control is less well understood.

In a recent study, the researchers used data from the electronic health records of 27,579 patients with hypertension and defined BP control as a BP <140/90 mm Hg. Overall, BP control was 65% among the participants and preferred dual antihypertensive therapy was prescribed in 55% of patients with uncomplicated hypertension, 49% of those with diabetes, and 47% of those with a history of myocardial infarction.

Consultant360 reached out to study authors Oyunbileg Magvanjav, MD, PhD, and Julie A. Johnson, PharmD, Dean and Distinguished Professor at the College of Pharmacy at University of Florida, to find out more about their research.

Consultant360: Why did you decide to focus your study on trends in antihypertensive prescribing patterns and the use of preferred combinations of medications?

Julie Johnson: Hypertension and uncontrolled hypertension remain a significant problem in the USA with one of every three adults with high blood pressure (>140/90 mmHg). In particular, hypertensive people with comorbidities require treatment with multiple antihypertensive drugs to achieve blood pressure control. Based on clinical trials, guidelines recommend certain anti-hypertensive drugs and drug combinations for people according to their comorbidities such as history of myocardial infarction or diabetes. However, we know little about how clinicians are prescribing antihypertensive medications to people in the community. In our study, we used de-identified electronic health records (EHR) data of hypertensive patients at the University of Florida Health (UF Health) healthcare system/network to examine real-world antihypertensive therapy prescribing practices according to comorbidity.

C360: You found that use of preferred dual antihypertensive therapy was present in roughly half of the patients studied. Why do you think these numbers are suboptimal?

Oyunbileg Magvanjav: We found that among patients requiring two antihypertensive medications to achieve blood pressure control, the prevalence of using a preferred combination by comorbidity subgroups was <60%. The discrepancy between guideline recommendations and practice is likely due to physician preference. For example, we found that ACEI inhibitor or ARB were prescribed in the majority (72%) of people in the subgroup who ought to be on it (hypertensive people with diabetes), but there are still about a quarter of patients not getting this strongly recommended therapy in diabetics.  Then when considering combination, the recommended dual therapy of ACE inhibitor or ARB plus a calcium channel blocker or diuretic was prescribed in only half of the patients in this subgroup. Despite the basis for this recommended dual therapy being pharmacological, clinicians likely chose another dual therapy combination based on preference or improved blood pressure control on other combinations.

In some cases where guidelines ought to take more precedence, we observed suboptimal prescribing practices. For example, among patients with a history of myocardial infarction, an ACE inhibitor combined with a beta-blocker is preferred regardless of other comorbidity, however, we found that post-MI patients with concomitant diabetes and/or CKD were less likely to receive this preferred combination than those without diabetes/CKD, which is concerning.   

JJ: We cannot discern from our data if the physicians are unaware of the treatment guidelines, have chosen the therapies they did for better BP control, or have misunderstandings about drug risks.  For example, in diabetics there is a general recommendation to avoid beta-blockers, because of the risk of elevating glucose and masking symptoms of hypoglycemia.  However, in the setting of hypertension plus post-MI, the benefit of beta-blockers is so substantial that one should not have the same concerns one would have about beta-blockers in a diabetic that hasn’t had a heart attack. Given that we saw higher beta-blocker use in post MI patients without diabetes, it implies that clinicians do not understand the subtleties of risk/benefit in beta-blockers in diabetics.  This is just one example of why we might see suboptimal use, but our data really cannot sort out the reasons.  

C360: What knowledge gaps still exist in this area of medicine?
 
OM: We can examine long-term outcomes associated with the prescribing of different antihypertensive drug regimens, which will be increasingly relevant as institutions have much longer time periods with electronic health record data. Also, we may explore the reasons for how clinicians are making their prescribing decisions, for example, through surveys or focus groups.  We may correlate our data with clinician’s demographic, training, and clinical background to see if these factors influence prescribing practices.  Also, thinking generally about prescribing practices, currently, we continue to prescribe antihypertensive therapy based on a trial-and-error method, which is not cost or time-efficient for patients and the healthcare system and could also reduce patients’ confidence in their clinical care. Research into alternative methods of improving prescribing practices, for example, through pharmacogenomics or using patients’ genetic information to determine, at the outset, the best therapy for a given patient, are ongoing in the field of hypertension and others.  

Reference:
Magvanjav O, Cooper-Dehoff RM, McDonough CW, et al. Combination antihypertensive therapy prescribing and blood pressure control in a real-world setting. AJH. 2020;33(4):316-324.