From the Guidelines
I would recommend restarting lisinopril for this 33-year-old male patient who is currently on hydrochlorothiazide 25mg with well-controlled blood pressure of 124/80. A typical starting dose would be lisinopril 10mg once daily, which can be titrated up to 20-40mg daily if needed for optimal blood pressure control. When adding lisinopril, it's reasonable to continue the HCTZ as these medications work well together through complementary mechanisms. The patient should be monitored for potential side effects including dizziness, cough, hyperkalemia, and acute kidney injury. Blood work should be checked within 1-2 weeks of starting lisinopril to assess kidney function and potassium levels, as the combination of an ACE inhibitor like lisinopril with a thiazide diuretic may increase the risk of hyperkalemia, particularly in patients with chronic kidney disease or those taking potassium-sparing medications 1. The combination of an ACE inhibitor like lisinopril with a thiazide diuretic provides synergistic blood pressure lowering effects - lisinopril blocks the renin-angiotensin-aldosterone system while HCTZ promotes sodium and water excretion. This combination may provide additional cardiovascular and renal protection beyond blood pressure control alone, particularly if the patient has conditions like diabetes, heart failure, or proteinuria. It is also important to note that the patient's current blood pressure is well-controlled, and the decision to restart lisinopril should be based on individualized assessment of the patient's risk factors and medical history, as recommended by the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1. Additionally, the patient's medication regimen should be regularly reviewed and adjusted as necessary to minimize the risk of adverse effects and optimize blood pressure control, as suggested by the 2018 synopsis of the 2017 American College of Cardiology/American Heart Association hypertension guideline 1.
From the FDA Drug Label
DRUG INTERACTIONS 7. 1 Diuretics Initiation of lisinopril in patients on diuretics may result in excessive reduction of blood pressure. The possibility of hypotensive effects with lisinopril can be minimized by either decreasing or discontinuing the diuretic or increasing the salt intake prior to initiation of treatment with lisinopril. If this is not possible, reduce the starting dose of lisinopril [see Dosage and Administration (2. 2)and Warnings and Precautions (5.4)]. To minimize the risk of hypotensive effects, the patient's current diuretic (HCTZ) should be either decreased or discontinued, or the patient's salt intake should be increased before starting lisinopril. If this is not possible, the starting dose of lisinopril should be reduced 2.
From the Research
Patient's Current Situation
- The patient is a 33-year-old male currently taking 25mg of Hydrochlorothiazide (HCTZ) with a blood pressure of 124/80 mmHg.
- He wants to get back on Lisinopril.
Studies on HCTZ and Lisinopril
- A study from 2003 3 found that a fixed combination of irbesartan 300 mg/HCTZ 25 mg administered once daily produced a significant reduction in 24-hour blood pressure and was well tolerated in patients with essential hypertension.
- A meta-analysis from 2011 4 found that the antihypertensive efficacy of HCTZ as measured by ambulatory blood pressure monitoring is consistently inferior to that of all other drug classes.
- A study from 2009 5 found that treatment with losartan 100 mg or losartan/HCTZ 100/25 mg was effective and well tolerated in high-risk patients with essential arterial hypertension and CV risk factors.
- A 52-week study from 1987 6 compared the antihypertensive efficacy and safety of lisinopril, HCTZ, and their combination in hypertension, and found that lisinopril appeared to be more effective than HCTZ as a step-1 drug, and the combination was superior to either agent alone.
- A study from 1988 7 found that therapy with lisinopril alone or in combination with HCTZ was equally effective in lowering blood pressure compared to placebo, and the incidence of side effects was similar in both groups.
Considerations for the Patient
- The patient's current blood pressure is 124/80 mmHg, which is considered to be within a normal range.
- The patient wants to get back on Lisinopril, which has been shown to be effective in lowering blood pressure in patients with essential hypertension 6, 7.
- The combination of Lisinopril and HCTZ has been shown to be superior to either agent alone in some studies 6.