lisinopril and Hypokalemia

Concerns exist that diuretic-induced changes in serum potassium may have adverse effects in hypertensive patients. The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, a large practice-based clinical trial, made it possible to examine consequences of observed changes in potassium during care in conventional practice settings. Normokalemic participants randomized to chlorthalidone (C) versus amlodipine or lisinopril as a first-step drug were stratified by year-1 potassium. Postyear-1 outcomes among hypokalemics (potassium, <3.5 mmol/L) and hyperkalemics (potassium, >5.4 mmol/L) were compared with normokalemics (potassium, 3.5-5.4 mmol/L). Year-1 hypokalemia incidence was 6.8%; incidence in C (12.9%) differed from amlodipine (2.1%; P<0.001) and lisinopril (1.0%; P<0.01). Hyperkalemia incidence (2.0%) was greater in lisinopril (3.6%) than in C (1.2%; P<0.01) or amlodipine (1.9%; P<0.01). Coronary heart disease occurred in 8.1% with hypokalemia, 8.0% with normokalemia, and 11.1% with hyperkalemia. Overall, mortality was higher in hypokalemics than in normokalemics (Cox hazard ratio, 1.21 [95% CI, 1.02-1.44]) with statistically significant (interaction, P<0.01) disparity in hazard ratios for the 3 treatment arms (hazard ratios, C=1.21, amlodipine=1.60, lisinopril=3.82). Hyperkalemia was associated with increased risk of combined cardiovascular disease (hazard ratio, 1.58 [95% CI, 1.15-2.18]) without significant treatment interactions. In conventional practice settings, the uncommon appearance of hyperkalemia was associated with increased cardiovascular disease risk. Hypokalemia was associated with increased mortality; however, the statistically significant heterogeneity in hazard ratios across treatment groups strongly suggests that the observed increase in mortality is unrelated to the specific effects of C. Thus, for most patients, concerns about potassium levels should not influence the clinician's decision about initiating hypertension treatment with low-moderate doses of thiazide diuretics (12.5-25.0 mg of C).

Topics: Aged; Amlodipine; Antihypertensive Agents; Blood Chemical Analysis; Cardiovascular Diseases; Chlorthalidone; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Female; Follow-Up Studies; Humans; Hyperkalemia; Hypertension; Hypokalemia; Incidence; Kaplan-Meier Estimate; Lisinopril; Male; Middle Aged; Myocardial Infarction; Proportional Hazards Models; Prospective Studies; Risk Assessment; Survival Rate; Treatment Outcome

Two combinations of lisinopril and hydrochlorothiazide (L/HCTZ, 20 mg/12.5 mg and 20 mg/25 mg) are currently marketed. The licences are based primarily on a dose ratio study and a parallel titration study. In the former randomized study of 209 patients with sitting DBP of 90-115 mm Hg, the antihypertensive effects of L/HCTZ 20 mg/12.5 mg and 20 mg/25 mg were significantly greater than either lisinopril or hydrochlorothiazide monotherapy (P less than or equal to 0.01), while the effect of L/HCTZ 20 mg/6.25 mg, was greater than hydrochlorothiazide but not lisinopril monotherapy. In the latter study, 394 patients with sitting DBP of 90-120 mm Hg received lisinopril 20 mg, HCTZ 12.5 mg, or L/HCTZ 20 mg/12.5 mg once daily for 12 weeks of double-blind therapy. All of the dose regimens could be doubled at 4 and 8 weeks for adequate BP control. The L/HCTZ group had significantly greater effect than either monotherapy (P less than or equal to 0.01). Thus, concomitant therapy with lisinopril and hydrochlorothiazide provides BP reduction beyond that of either monocomponent. Studies on new combinations of lisinopril and hydrochlorothiazide are under way to increase prescribing options for practitioners.

Topics: Angiotensin-Converting Enzyme Inhibitors; Blood Pressure; Double-Blind Method; Drug Combinations; Enalapril; Humans; Hydrochlorothiazide; Hypertension; Hypokalemia; Lisinopril

We report the association between excessive consumption of green tea and hypokalaemia in an Oriental couple. Both patients were asymptomatic and the abnormal electrolyte level was only detected on routine blood tests. When they were advised to reduce the consumption of green tea, the abnormally low potassium level was reversed. We have not found such an association reported in the medical literature. The health benefits of green tea consumption are well publicised but the potential side-effects of overconsumption are less well known. We would like to report this association to alert clinicians about this potentially serious complication. This is especially relevant for those who are also taking prescribed medications that can lower potassium levels and/or sensitise patients to potential harm from hypokalaemia.

Topics: Aged; Amlodipine; Antihypertensive Agents; Bendroflumethiazide; Drinking Behavior; Female; Humans; Hypertension; Hypokalemia; Lisinopril; Male; Tea

Topics: Antihypertensive Agents; Carbohydrate Metabolism; Clinical Trials as Topic; Diuretics; Drug Therapy, Combination; Drugs, Generic; Heart Diseases; Humans; Hypertension; Hypokalemia; Indapamide; Lipid Metabolism; Lisinopril; Stroke; Thiazides