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CPD Zone update

this module covers:

● The main risk factors and causes of hypertension, its diagnosis and assessment

● The clinical classifications of hypertension and how these affect management

● The stepwise treatment of hypertension, and recommended drugs for different groups

● Common cautions and antihypertensive side effects pharmacists must know

UPDATEmodule 1649

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● Statins: six case studies March 2

● Myocardial infarction 1 March 9

● Myocardial infarction 2 March 16

● Hypertension March 30April is mental health month, starting with a look at antipsychotics

Managing hypertension

www.chemistanddruggist.co.uk/update

Jill Peaston

Hypertension is one of the most important modifiable risk factors for cardiovascular, cerebrovascular and renal disease, and one of the most preventable and treatable causes of premature deaths worldwide.1

In England in 2011, the prevalence of hypertension – defined as a blood pressure ≥140/90mmHg, or the person receiving treatment for hypertension – was around 30 per cent.2

Prevalence significantly increases with age: about 73 per cent of men and 64 per cent of women aged 75 years or over have hypertension.

Every 2mmHg rise in systolic blood pressure is associated with a 7 per cent increased risk of mortality from ischaemic heart disease and a 10 per cent increased risk from stroke.

risk factors and causesHypertension is a major risk factor for stroke, myocardial infarction, heart failure, chronic kidney disease, cognitive decline and premature death. It also causes hypertensive retinopathy, metabolic syndrome, erectile dysfunction, obstructive sleep apnoea and bone loss.

Untreated hypertension is associated with a progressive rise in blood pressure, causing vascular and renal damage and culminating in treatment-resistant hypertension. The vast majority of cases are symptomless and only found through tests.

For most adults there is no identifiable cause of hypertension; this is called essential or primary hypertension. Less than 10 per cent of cases are caused by an underlying condition, known as secondary hypertension. Possible causes of secondary hypertension include renal disease, pregnancy, endocrine disorders, coarctation (narrowing of the aorta) and congenital blood vessel defects. Drugs that may be implicated include: ● alcohol● cocaine● amphetamines● ciclosporin

● tacrolimus● erythropoietin ● adrenergic medications● NSAIDs● oral contraceptives● steroids● ephedrine● remedies containing liquorice ● HRT in postmenopausal women.

Blood pressure increases with age as blood vessels become less elastic. Isolated systolic hypertension (where systolic ≥160 mmHg and diastolic <90mmHg) is common in those aged over 60 years, and associated with an increased risk of cardiovascular disease (CVD).

Hypertensive complications in pregnancy are associated with a significant risk of morbidity and mortality for the mother and the foetus; complications occur in women with pre-existing chronic hypertension, or who develop hypertension during pregnancy.

DiagnosisEveryone aged over 40 years should have their blood pressure checked at least every five years up to the age of 80, and then at least annually.

Patients with a blood pressure of

≥140/90mmHg should be offered ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis and stage of hypertension, or home blood pressure monitoring (HBPM) if ABPM is not available or not tolerated. If using ABPM, two or more readings are taken every waking hour, and the average of at least 14 measurements used. If using HBPM, two consecutive blood pressure measurements are taken less than a minute apart, with the person seated. Readings are taken morning and evening over at least four (ideally seven) days. Readings from the first day are disregarded, then the average of the rest used.

While waiting for confirmation of diagnosis, evidence of target organ damage (left-ventricular hypertrophy, chronic kidney disease and hypertensive retinopathy) should be investigated, and an assessment of cardiovascular risk undertaken; Nice recommends this is performed within one month of diagnosis at the latest.

Patients with blood pressure of 130 to 139/85 to 89mmHg measured using ABPM or HBPM should be checked annually.

Non-hypertensive individuals should have their blood pressure checked every five years, ▶

everyone over 40 years should have their blood pressure checked at least every five years

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most hypertensive patients every six months, and those with uncontrolled hypertension every four to eight weeks.

treatment of hypertensionTreatment uses a step-wise approach; an interval of at least four weeks should be allowed to assess response and each step should be titrated to the optimum or maximum tolerated dose: ● Step one Treatment follows a set protocol depending on the patient’s age and ethnicity: patients under 55 years of age are prescribed an ACE inhibitor or low-cost angiotensin receptor blocker (ARB), while those older than 55 years or of black African or Caribbean origin are prescribed a calcium channel blocker (CCB). ● Step two Patients are prescribed an ACE inhibitor/ARB and a CCB. ● Step three As for step two, with a thiazide diuretic added.

An algorithm showing when to use each drug is available to Update Plus subscribers in the online version of this article.

Combination products with an ACE inhibitor and a thiazide diuretic or a CCB should be reserved for patients who are stabilised on the individual components in the same proportions.

Chlortalidone or indapamide should be used at step three rather than bendroflumethiazide or hydrochlorothiazide. However, those already taking bendroflumethiazide or hydrochlorothiazide should continue on their existing treatment if their blood pressure is stable and controlled.

Benefit from antihypertensive therapy is seen up to the age of 80. Patients of 80 years taking antihypertensive drugs should continue treatment, provided it is beneficial and side effects are not evident.

For patients aged over 80 years with stage one hypertension (see Box 1, right), the decision to treat considers comorbidities; those over 80 with newly diagnosed stage two hypertension are treated as for patients over 55 years. The target clinic blood pressure for those aged over 80 years is <150/90mmHg, and an ABPM or HBPM of <145/85mmHg.

For diabetics, the target blood pressure is <140/80mmHg, or below 130/80mmHg if there are kidney, eye or cerebrovascular disease comorbidities. Hypertension is common in type 2 diabetes, and treatment can prevent vascular complications; an ACE inhibitor (or ARB) can delay progression of microalbuminuria to nephropathy.

In type 1 diabetes, hypertension usually indicates diabetic nephropathy. An ACE inhibitor (or ARB) can have a role in the management of diabetic nephropathy.

In renal disease the target clinic blood pressure is <140/90mmHg and <130/80mmHg for chronic kidney disease, or if proteinuria exceeds 1g in 24 hours.

Isolated systolic hypertension is treated as for patients with both a raised systolic and

diastolic blood pressure. Patients with severe postural hypotension need specialist referral.

In addition to antihypertensive therapy, Nice recommends that all patients with hypertension who have a 10-year cardiovascular risk of 20 per cent or greater should be offered a statin.

Cautions and side effectsThe first dose of an ACE inhibitor may cause a rapid drop in blood pressure and should be given at bedtime. In volume-depleted patients (diuretic therapy, low-sodium diet, dialysis, dehydrated, heart failure) treatment starts with low doses, and any diuretic may be reduced or discontinued beforehand. The most common side effect is dry cough, which can appear at any time. NSAIDs can reduce the antihypertensive effect of ACE inhibitors and increase the risk of renal problems.

Patients should have their renal function and electrolytes checked before starting ACE inhibitors or increasing their dose, and should be monitored during treatment. ACE inhibitors occasionally cause impairment of renal function, which is a particular risk in the elderly.

Plasma potassium should be monitored if taking ARBs, particularly in the elderly or with renal impairment; lower initial doses may be needed. Side effects include hypotension and dizziness, particularly in volume-depleted patients.

Beta blockers can precipitate bronchospasm and are avoided in asthma. Beta blockers can also affect carbohydrate metabolism and are avoided in those with frequent hypoglycaemia.

Alpha blockers may reduce blood pressure rapidly after the first dose, especially if given

with beta blockers, CCBs or diuretics.The most common side effect with CCBs is

ankle swelling. Elevating the leg when sitting or using compression stockings, reducing the dose of the CCB or adding an ACE inhibitor or ARB can help. Diuretics are not effective for CCB-induced ankle oedema.

Thiazide-like diuretics are taken in the morning to minimise sleep disturbance, but patients can alter this to fit in with social events if needed. Indapamide may take several months to reach the maximum reduction in blood pressure. Renal function and electrolytes should be monitored within four to six weeks of starting therapy and then every six to 12 months, and more frequently if the patient is predisposed to electrolyte disturbances. Diuretics are implicated in many drug-related hospital admissions so careful evaluation of interactions can improve their safe use.3 Extra care is needed when diuretics are used with NSAIDs.

ACE inhibitors, ARBs and thiazide-like diuretics can significantly increase serum lithium levels, causing toxicity.

role of the pharmacistPharmacists have a role in identifying patients with hypertension and helping those with high levels reduce their cardiovascular risk. The Department of Health’s vascular risk programme (NHS health checks) targets those aged 40 to 74 years, and aims to identify the risk of vascular disease early and to reduce it.

Pharmacists can advise patients about lifestyle changes that can reduce blood pressure and cardiovascular risk, including smoking cessation, weight reduction, reduction of excessive intake of alcohol and caffeine, reduction of dietary salt, reduced fat consumption, increasing exercise, and increasing fruit and vegetable intake.

Advice should be supported by written or audio-visual information for the patient to keep. Opportunities to discuss lifestyle issues may arise when offering healthy living advice, supplying medicines, as part of MURs or the new medicine service (England), discharge medicines reviews (Wales) or chronic medication service (Scotland).

People can feel motivated to make lifestyle changes if they might reduce their need for long-term medication.

Targeted interventions for practical problems associated with non-adherence could include the patient keeping a record of their medicine intake, encouraging patients to monitor their condition, simplifying dosing regimens, using appropriate packaging for the patient, or a multi-compartment medicines system. Pharmacists should also consider the sodium content of medicines for hypertensive patients.

Box 1. Classification of hypertension

● stage one hypertension Clinic blood pressure ≥140/90mmHg, and ABPM or HBPM average ≥135/85mmHg. Patients under 80 years with stage one hypertension and target-organ damage, CVD, renal disease, diabetes, or a 10-year cardiovascular risk of 20 per cent or higher are offered antihypertensives. Otherwise they are advised about lifestyle and reviewed annually. Patients under 40 years with stage one hypertension but no overt target-organ damage, CVD, renal disease, or diabetes are referred to a specialist.● stage two hypertension Clinic blood pressure ≥160/100mmHg, and ABPM or HBPM average ≥150/95mmHg. All patients with stage two hypertension should be treated.● severe hypertension Clinic systolic blood pressure ≥180mmHg or clinic diastolic blood pressure ≥110mmHg. Patients with severe hypertension need prompt treatment without waiting for the results of ABPM or HBPM.

CPD Zone update

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1. Every 4mmHg rise in systolic blood pressure is associated with a 7 per cent increased risk of mortality from ischaemic heart disease. True or false?2. About 20 per cent of cases of hypertension are caused by underlying conditions. True or false?3. Drugs that may cause hypertension include cocaine, amphetamines, ciclosporin, NSAIDs, and steroids. True or false?4. Stage two hypertension is where clinic BP is 180/110 mmHg or higher. True or false?5. The first-choice treatment of hypertension in non-black people aged under 55 years is a calcium channel blocker. True or false?6. Chlortalidone or indapamide are the diuretics of choice for treatment of hypertension. True or false?

7. The target clinic BP for those aged over 80 years is below 150/90 mmHg. True or false?8. NSAIDs can reduce the antihypertensive effect of ACE inhibitors. True or false?9. The most common side effect with calcium channel blockers is ankle swelling. True or false?10. ACE inhibitors and thiazide-like diuretics can significantly increase serum lithium levels, causing toxicity. True or false?

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references1. World Health Organization. The World Health report 2002; reducing risks, promoting healthy life. WHO,Geneva, 20022. http://www.ic.nhs.uk/catalogue/PUB09300 Health Survey for England - 2011, Health, social care and lifestyles Publication date: December 20, 2012

Tips for your CPD entry on hypertensionReflect What are the causes of secondary hypertension? Which drugs are used for the treatment of stage two hypertension? What are the side effects of calcium channel blockers?

Plan this article describes hypertension and includes information about causes, risk factors, diagnosis and classification. treatment is also discussed, including the drugs suitable for different patient groups and their side effects, as well as lifestyle advice that pharmacists can give.

Act read the article and the suggested reading (below), then take the 5 minute test (left). update and update Plus subscribers can then access their answers and a pre-filled CPD logsheet.

read more about hypertension on the Nhs Choices website, which also contains useful lifestyle advicehttp://tinyurl.com/hypertension1Find out more about ambulatory blood pressure monitoring on the Patient uK websitehttp://tinyurl.com/hypertension2Find out more about cardiovascular risk assessment on the Patient uK websitehttp://tinyurl.com/hypertension3read the mur tips for hypertension on the C+D websitehttp://tinyurl.com/hypertension4

Evaluate Are you now confident in your knowledge of the causes, risk factors and treatments for hypertension? Could you give advice to patients about medication and lifestyle changes that could reduce risks?

Ask your questions on mental healthApril is mental health month in Update – and our expert is on hand to answer your queries. From SSRIs to antipsychotics, submit your questions now via chris.chapman@ubm.com

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Antihypertensive drug treatment

Source: Nice 2013