Case Study #1 Hypertension
Case:
Your patient is a 69-year-old African-American woman who presents for a follow-up for her blood pressure. You evaluated her one month ago, and at that time, her blood pressure had increased (146/90 mmHg) from the previous office visit (138/88 mmHg). In the office today, the patient’s blood pressure is 148/92 mmHg. The patient has a history of type II diabetes mellitus, for which she takes metformin BID. Her most recent creatinine was 1.4. She admits that she has not been watching her diet as much as she should have. You decide that she needs medication to help control her high blood pressure. BMI: 31.6; H: 5’5”; W: 190lbs.
Class of Medication to be given (the hypertension Management Algorithm)
The management of hypertension in older African-American adults with concomitant type II diabetes is dependent on a careful consideration of the effects of advancing age on the metabolism of drugs and changes in the health status which can potentially have effects on the therapeutic intervention (Munger, 2010). Additionally, the presence of other concomitant illnesses such as chronic kidney diseases and diabetes should be noted and if possible, managed. The blood pressure target when managing a 69-year-old African-American with diabetes pressure is <140 mmHg for systolic BP and <90 mmHg for the diastolic BP. Initially, the recommended management of hypertension is non-pharmacological therapy, which includes lifestyle medication: eating recommended foods, reducing salt intake, and avoiding fast food (discussed below) (Munger, 2010).
Thiazides
Pharmacologically, low-dosages of thiazides are recommended for the treatment and management of blood pressure. This low dose thiazide diuretic can be administered alone or in combination with a CCB, alone or together. According to Tripathi (2016), it is recommended that the initial therapy for the management of non-complicated (essential) hypertension be a low dose of thiazides (12.5-25 mg), administered preferably in conjunction to a potassium sparing diuretic. The administration of higher doses of these medications above the recommended ceiling is neither more efficacious nor safer (Tripathi, 2016). If these low dosages (of < 25mg of thiazides per day) fail to arrest the BP and lower it to the target levels, it is recommended that another antihypertensive drug should be added to the regimen, other than increasing the dosages of the thiazide diuretic (Tripathi, 2016). However, in instances where the administration of sympatholytic/vasodilators for the management of severe hypertension induced the retention of fluids (and expansion of volume), it is recommended then to administer higher dosages of loop diuretics (James et al., 2014). Notwithstanding these two, other antihypertensives may be more appropriate in other subgroups of patients. Notably, the administration of diuretics is associated with impairment of the quality of life in some patients; impairment of physical activity (James et al., 2014).
Calcium Channel Blockers (CCBs):
When using Calcium Channel Blockers (CCBs) as compared to thiazides, the onset of the antihypertensive action of calcium channel blockers is rapid. These drugs also confer an advantage in that there are long-acting formulations available, and they can effectively be administered once daily (Tripathi, 2016). The administration of a monotherapy with Calcium Channel Blockers has been proved to be effective in up to ~ 50 percent of hypertensive patients; the action of these drugs is dependent on the renin status of the patients, and that they have the potential to improve arterial compliance (Tripathi, 2016). Further, Calcium Channel Blockers do not compromise patient hemodynamics and confer no impairment in the capacity to do physical work. These drugs do not produce sedation or other negative Central Nervous System side effects; they do not affect normal cerebral perfusion. CCBs are not contraindicated in patients with angina (specially the variant type), asthma and PVD. These drugs, therefore, may benefit patients with these conditions. The drugs do not impair perfusion of the kidneys and have no negative effects on plasma electrolyte levels, serum uric acid levels, and plasma lipid profiles (this is of particular importance for this patient) (Tripathi, 2016). According to James et al. (2014), the drugs have shown to have no/minimal negative effect on quality of life.
Calcium Channel Blockers have been considered by the JNC 7 to be less suitable for monotherapy in the management of hypertension with no other risk factors (Tripathi, 2016). This is majorly because they have been proved to afford less prognostic benefits than the administration of β blockers, thiazides, and Angiotensin Converting Enzyme inhibitors/ARBs. CCBs, however, have continued to be widely used as one of the first-line monotherapy options because of their excellent tolerability and high efficacy (Tripathi, 2016). CCBs are the drugs preferred for the management of uncomplicated hypertension in elderly patients. Additionally, researchers have posited some evidence on the potential of CCBs in preventing strokes (Adverse Cerebrovascular accidents) (Jams et al., 2014). Formulation of long acting DHTs are next to the Angiotensin Converting Enzyme Inhibitors in the reduction of albuminuria and slowing the progression in hypertensive/diabetic nephropathy. They are the most useful antihypertensive drugs in the management of cyclosporine-induced hypertension in patients who have received renal transplants (James et al., 2014).
The administration of fast-acting oral Nifedipine (DHP) for the management of Blood pressure in hypertensive emergencies is outmoded. In reality, there exists no clear therapeutic indications for the short-acting and rapid institution of oral DHPs in the management of hypertension (James et al., 2014). Other effects on the use of CCBs that have raised concern include: The negative inotropic/dromotropic effects of diltiazem/verapamil has been proved to worsen Congestive Heart Failure and defects in cardiac conduction (DHPs have a less tendency to induce these side effects). Secondly, by action on the laxative effect on smooth muscles, the DHPs have the potential of worsening gastroesophageal reflux. Thirdly, CCBs (more so the DHPs) have the potential to accentuate bladder voiding difficulties in elderly male patients (James et al., 2014).
Medications and their Prescription (Dosing and Timing)
Research recommended that the first line of drugs for the management of hypertension in elderly patients with non-concomitant illnesses be diuretics. This is because they have been demonstrated to lower the prevalence of adverse cardiovascular events and mortality in RCTs (Aronow et al., 2011). However, the selection of an anti-hypertensive drug in an elderly patient with diabetes is dependent on the target blood pressure (Tripathi, 2016). If, for example, the BP in 20/10 mmHg units above the targeted pressure, the initiated drug therapy is preferably with two the combination of antihypertensive medications, of which one should be a thiazide diuretic. The effective drug regimen thereof is:
Table 1: Drug Dosing
| Drug class | Examples | Dosages |
| Thiazide diuretics | Chlorothiazide | Once daily dosing. The dosing should bet between 12.5 to 2.5 mg/day |
| OR | ||
| CCBs | Verapamil | 40 to 160 mg given TDS orally, 5 mg administered as a slow intravenous injection (first line) |
| Diltiazem | 30 to 60 mg TDS–QID oral (first line) | |
| Nifedipine | 5 to 20 mg BD–TDS given orally | |
| Felodipine | 5 to10 mg OD, a maximum of 10 mg BD. | |
| Amlodipine | 5 to 10 mg OD; | |
| Nitrendipine | 5 to 20 mg OD | |
| Lacidipine | 4 mg OD, increase to 6 mg OD if necessary. | |
| Lercanidipine | 10 to 20 mg OD | |
| AND | ||
| Management of diabetes mellitus with metformin BID | ||
Considerations or Contraindications
According to James et al. (2014), before initiating any antihypertensive drug therapy, the dosages administered should be lowest and bit by bit increased to a ceiling dosage. If the response to the initial antihypertensive drug is inadequate after attainment of the maximum dosage recommendations for the drug, the second drug from another class is preferably administered if the patient tolerates the initial drug (James et al., 2014). If the patients prove to have significant adverse effects or no therapeutic response, the drug should be substituted with a medication from another class. If the diuretic is not the initial drug, it is usually indicated as the second drug (Weber et al., 2014). After achieving full dosages of two classes of antihypertensive and the patient still has no response, the third class from another class should be added.
Weber et al. (2014) posit that the physician should consider the possible reasons for the inadequacy of the antihypertensive drug administered before the addition of another drug. These include non-adherence to the drug regimen, volume overloads, pseudo-resistance, interaction with other drugs (the use of caffeine, NSAIDs, nasal decongestants, antidepressants, sympathomimetic and sympatholytic among others) and other associated conditions such as smoking, insulin resistance, increasing obesity and excessive consumption of ethyl alcohol (Tripathi, 2016). These secondary causes of resistance should be identified and treated.
All antihypertensive medication, more so e ACE inhibitors, diuretics, CCBs, nitrates, and ARBs predispose elderly patients to the development of symptomatic orthostatic hypotension, postprandial hypotension, syncope and associated falls (Weber et al., 2014). Diuretics may cause volume depletion. It is, therefore, important the patients are adequately hydrated. Decreasing in baroreflex sensitivities accosted with age and with hypertension impair the baroreflex-mediated increases in the total systemic vascular resistance, and to inabilities in increasing the heart rate. This is why older have a higher predisposition to developing orthostatic and postprandial hypotension.
If the patients cannot tolerate Angiotensin converting enzyme inhibitors due to side effects such as coughs, rashes, angioneurotic edema or alteration of taste, an ACE type 1 receptor blocker is recommended (Aronow et al., 2011). Coughs have been noted to occur in 5-20% of patients under a regimen of ACEIs. Angioneurotic edema occurs in 0.1-0.2% of patients treated with ACE inhibitors (Tripathi, 2016). Potassium-sparing diuretics are contraindicated in persons receiving ARBs of ACEs because of the risk of hyperkalemia
Non-Pharmacologic Blood Pressure Control Measures
The combination of both economical stresses and the allures of the benefits of lesser side effects have led to the rise of lifestyle changes as an attractive proposition in both developed and developing countries as well (Aronow et al., 2011). While the use of hypertensive drugs is for patients with a BP above the traditional cutoff, there is a continued increase of emphasis on the prevention and treatment of hypertension by non-pharmacological means – modifications in lifestyle. The lifestyle changes are listed below:
Table 2: Lifestyle modifications
| Lifestyle modification | Rationale and strategy |
| Stop smoking | Smoking is a risk factor for HTN |
| Lose weight | The lost weight should be relative to the BMI. The aim is to maintain a healthy adult weight (BMI of 20-25 kg/m2) (James et al., 2014). |
| Review and advise on diet | Food high in animal fat and cholesterol should be avoided. The patient should be encouraged to have a greater intake of fruits, vegetable, fish and other foods with monounsaturated and polyunsaturated fats. The target is for the patient to consume a minimum of five daily portions of fresh fruits and vegetables. Excessive caffeine consumption should be discouraged (Weber et al., 2014) |
| Total lifestyle changes | Saturated fats should make up < 7% of the calories consumed, with consumption of < 200 mg per day of cholesterol. The physician should also advise the patient to consider the consumption of foods with viscous (soluble) fiber (the amount being 10 to 25 g per day) and plant stanols/sterols (2g per day) as therapeutic options to lower LDL |
| Alcohol consumption | Women: < 14 units per week Men: < 21 units per week. |
| Reduce the intake of salt | Lower the intake of salt < 100 mmol per day (or less than 6 g of Sodium Chloride or less than 2.4g Na+ on a daily basis) (James et al., 2014). Reduce salt in food preparations. The patient should also foods with a high content of salt (read food labels) |
| Regular exercise | The patient is advised to engage in regular aerobic activities (brisk walking rather than weight lifting) for 30mins daily, ideally at least on three days of the week |
Further Pharmacologic Steps if the BP is not Controlled
If the target blood pressure is not achieved, the doctor can then reinforce lifestyle adherence and medication. Strategy A and B: Steps A and B require that the physician has to maximize first the initial medication addition of the second or add a second medication before the achievement of maximum dosages for the first medication. If the patient has not achieved the desired blood pressure levels after levels A and B, drugs to be included are a titrated thiazide-type diuretics or ACEI or ARB or CCB. That the physicians should use a medication class not previously used and should avoid the combined use of ACEI and ARBs). Strategy C: Start with two drug classes separately or as fixed dose combination. If this fails, titrate doses of initial medications to the maximum.
References
Aronow, W. S., Harrington, R. A., Fleg, J. L., Pepine, C. J., Artinian, N. T., Bakris, G., Brown, A. S., Ferdinand, K. C., Forciea, M. A., Frishman, W. H. & Jaigobin, C. (2011). ACCF/AHA 2011 expert consensus document on hypertension in the elderly. Circulation, 123(21), 2434-2506.
James, P. A., Oparil, S., carter, B. L., Cushman, W. C., Dennison-Himmelfarb, C., Handler, J., Lackland, D. T., LeFevre, M. L, Mackenzie, T. D., Ogedegbe, O. & Smith, S. C. (2014). 2014 evidence-based guideline for the management of high blood pressure in adults: a report from the panel members appointed to the eighth Joint National Committee (JNC 8). Jama, 311(5), 507-520.
Munger, M. A. (2010). Polypharmacy and combination therapy in the management of hypertension are elderly patient with comorbid diabetes mellitus. Drugs and Aging, 27(11), 871-883.
Tripathi, K. D. (2016). Essentials of medical pharmacology. New Delhi: Jaypee Brothers Medical Publishers (p), Ltd. Print Book: English.
Weber, M. A., Schiffrin, E. L., White, W. B., Mann, S., Lindholm, L. H., Kenerson, J. G., Flack, J. M., Carter, B. L., Materson, B. J., Ram, C. V. S. & Cohen, D. L. (2014). Clinical practice guidelines for the management of hypertension in the community. The Journal of clinical hypertension, 16(1), 14-26.
