Resisting Blood Pressure Meds

Alpesh has high blood pressure. In fact, the 55 year old keeps having high blood pressure despite your best efforts over the past two years. He is already on triple antihypertensives. Does he need a fourth? Do you need to refer him for specialist assessment of resistant hypertension?

The UK government this month begins consultation on its first Men’s Health Strategy. Men are 60% more likely to die under the age of 75 than women and the most common cause is cardiovascular disease. Up to 80% of premature deaths due to CVD are preventable, so successfully addressing this would narrow the historic gap in lifespan seen between women and men.

Identifying and improving modifiable risk factors is key, and hypertension is one of the most important. 

But what do we do when our patient’s blood pressure just won’t come down? 

To start with it is worth going back to basics. Overweight and obesity, excess alcohol consumption and high salt intake can all contribute to stubborn blood pressures. The British and Irish Hypertension Society (BIHS) guideline for resistant hypertension quotes that a BMI of >30 doubles the risk of resistant HT and a reduction in body weight of 6-8% reduces blood pressure by an average of 5/4mmHg. Reducing salt intake by 3g/day results in a decrease of 3.5/2mmHg, perhaps even more so in patients taking ACEi or ARB.

But Alpesh is not overweight, doesn’t drink alcohol and has been keeping an eye on his salt intake. Some patients are going to need medication.

In fact it’s estimated that at least 25% of patients with hypertension will need triple anti-hypertensive therapy to achieve BP control. Of course we need to consider iatrogenic causes, like NSAIDs and corticosteroids, and primary hyperaldosteronism amongst other causes of secondary hypertension, however, as we ramp up the number of medications a patient takes, there is one really important question we need to ask.

Are you taking your meds?

A recent BJGP editorial suggests the most common reason that triple therapy fails to control blood pressure is poor adherence. 

It is not new information to us in general practice that most patients don’t like taking medications, but it is easy to under-estimate the scale of non-adherence with anti-hypertensives. A 2017 study demonstrated through analysis of urine and serum sampling that rates of non-adherence to treatment in a UK hypertensive population was 42% and the BIHS as high as 50% in people with apparent resistant hypertension. I have patients that happily tell me they only take their pills on days they feel their blood pressure is up. I keep trying to explain why this strategy fails on a number of levels… 

There are many reasons for poor adherence. While data suggests that many simply forget to take their medicine regularly, combination tablets, pill reminder apps or dosette boxes are not always the solution. Many patients may avoid blood pressure medications due to side effects. While a patient is likely to tell you about ankle swelling, they may not admit to iatrogenic erectile dysfunction. A patient may not want to explain they are struggling financially and paying for blood pressure pills is at the end of a long list of other priorities. It could be a language barrier or ineffective communication. It may be a lack of perceived benefit given the absence of symptoms. It may be concern around the effect on other co-morbidities or interaction with other treatments.

This requires a classic general practice – thinking holistically, building relationships, understanding how the community we work in influences our patients’ health. Crucially, when the blood pressure is not controlled, before we add another drug we need to be curious - look for under-prescribing, ask about adherence, and if adherence is an issue, why?

Of course, men have a stereotype of not wanting to talk about health problems with their doctor, but this is a theme for another blog or you could join us on Saturday 17^th May for Hot Topics Men’s Health for Primary Care course. If you are looking to learn more about men’s health or upskill your existing knowledge, this half day course will cover a range of topics including prostate and genital disease, androgen insufficiency and much more. We will see you then.