How to adjust felodipine and bisoprolol for uncontrolled hypertension in an elderly patient with a history of hyponatraemia?

Hypertension Management in Elderly Patient with Resolved Thiazide-Induced Hyponatraemia

Increase felodipine to 20 mg daily as the next step, as this patient's BP of 145/66 mmHg represents inadequately controlled isolated systolic hypertension requiring dose optimization of the current calcium channel blocker before adding additional agents. 1

Rationale for Felodipine Dose Escalation

• The current felodipine dose of 10 mg daily is submaximal, and FDA labeling supports titration up to 20 mg once daily for inadequate blood pressure response 1
• Felodipine produces dose-related decreases in systolic and diastolic blood pressure, with clinical trials demonstrating efficacy at doses ranging from 2.5 to 20 mg daily 1
• In elderly patients, systolic blood pressure (SBP) is the superior target for treatment and risk stratification, correctly classifying BP stage in 94% of adults over 60 years old compared to only 66% for diastolic blood pressure 2

Target Blood Pressure in This Elderly Patient

• The target should be systolic BP <160 mm Hg as a prudent threshold, though some guidelines suggest <140 mm Hg if tolerated 2
• The current BP of 145/66 mmHg shows the systolic component remains suboptimal, while the diastolic of 66 mmHg is acceptable and should not be lowered further 2
• There is no definitive evidence of increased risk from aggressive treatment (J-curve) unless diastolic BP is lowered to 55-60 mm Hg, so the current diastolic of 66 mmHg provides a safe margin 2

Why Not Increase Bisoprolol

• Beta-blockers are less preferred in elderly patients over 60 years, with the MRC trial suggesting low-dose diuretic treatment is superior to β-blockers in this age group 2
• Beta-blockers can worsen orthostatic hypotension risk, which increases with age and carries a 64% increase in age-adjusted mortality 2
• The current bisoprolol dose of 2.5 mg daily is already providing heart rate control (pulse 53 bpm), and further increases risk excessive bradycardia 3

Avoiding Thiazide Diuretics

• Thiazide diuretics are absolutely contraindicated in this patient given the recent history of thiazide-induced hyponatraemia (sodium nadir of 127 mmol/L) 2
• While thiazides are typically first-line add-on therapy for resistant hypertension, this patient's documented adverse reaction makes them inappropriate 2
• The resolved hyponatraemia (sodium now 135 mmol/L) occurred only after thiazide discontinuation, confirming causality 2

Titration Strategy for Elderly Patients

• Use a slow, gradual titration approach over 2-4 weeks rather than aggressive dose escalation, as elderly patients deserve consideration for slower titration due to variable BP responses 2
• Monitor for orthostatic hypotension by checking both sitting and standing blood pressures at each visit, as this occurs in approximately 7% of men over 70 years old 2
• Assess for symptoms of postural unsteadiness, dizziness, or fainting before each dose increase, as orthostatic hypotension is strongly correlated with falls, fractures, and premature death 2

If Felodipine 20 mg Proves Insufficient

• Add a non-thiazide third agent only after maximizing felodipine to 20 mg daily and confirming inadequate response over 2-4 weeks 2, 1
• Consider an ACE inhibitor or ARB as the next agent, as these combine effectively with calcium channel blockers and provide renal protection 2
• Avoid the combination of thiazide plus beta-blocker, as this combination has dysmetabolic effects that may be pronounced when administered together, particularly in elderly patients 2

Critical Monitoring Parameters

• Check blood pressure within 1-2 weeks after each dose adjustment to assess response and detect excessive hypotension 2
• Monitor serum sodium and renal function periodically, as the patient has demonstrated susceptibility to electrolyte disturbances 2
• Measure both sitting and standing BP at each visit to detect orthostatic changes, which are a common barrier to intensive BP control in elderly patients 2

Common Pitfalls to Avoid

• Do not add a second agent before optimizing the first agent's dose, as this violates the principle of sequential monotherapy optimization before combination therapy 2
• Do not target diastolic BP <60 mm Hg, as this may increase coronary events in patients with established ischemic heart disease 2
• Do not restart thiazide diuretics under any circumstances in this patient given the documented severe hyponatraemia (sodium 127 mmol/L) 2
• Avoid the misconception that elderly patients have "brittle hypertension" requiring acceptance of suboptimal control—this has contributed to widespread inadequacy of drug titration 2