SUPPLEMENTARY FILE

Dose Doubling, Relative Potency, and Dose Equivalence of Potassium Sparing Diuretics Affecting Blood Pressure and Serum Potassium: Systematic Review and Meta-Analyses

George C. Roush,1,2 Michael E. Ernst3, John B. Kostis4, Shamima Yeasmin,2 and Domenic A. Sica5

1Corresponding author 2UCONN School of Medicine and St. Vincent’s Medical Center, Department of Medicine, Bridgeport, CT, USA 3University of Iowa Hospital and Clinics, Department of Family Medicine, Iowa City, IA, USA 4Cardiovascular Institute, UMDNJ-Robert Wood Johnson Medical School, Chairman, Department of Medicine, New Brunswick, NJ, USA 5Department of Medicine and Pharmacology, Virginia Commonwealth University, Richmond, VA, USA

METHOD FOR OBTAINING DOSE EQUIVALENCIES

To obtain dose equivalency, a generalized method assumes that (1) changes in SBP caused by the log doses of the two drugs, A & B, are linear and fail to “bottom out” at higher doses and (2) dose-response effects for the two drugs are parallel. These assumptions were supported by the data.

The general model is: SBP change = I – D*ln(Dose) – E*(1 if drug=A) – E*(0 if drug is B), where I, D, and E are constants.

For drug B to compensate for its lesser potency: I – D*ln(Dose of A) – E*1 must equal I –D*ln(Dose of B) – E*0. This comes out to Dose of A = Dose of B*Exp(E/D).

REFERENCES FOR META-ANALYSES

TRIAMTERENE

Kohvakka A, Salo H, Gordin A, Eisalo A. Antihypertensive and biochemical effects of different doses of hydrochlorothiazide alone or in combination with triamterene. Acta Med Scand. 1986;219(4):381-6.

Webb EL, Godfrey JC, Gertel A, Costello RJ, Applin WJ, Zisblatt M, Vukovich RA, Neiss ES. The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. I. J Int Med Res. 1984;12(3):133-9.

Webb EL, Godfrey JC, Gertel A, Costello RJ, Cooper WH et al. The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. II. J Int Med Res 1984;12:140-146.

AMILORIDE

Chrysant SG, Brown JL, Hagstrom D. J Clin Pharmacol. 1983 Apr;23(4):147-54.

Hood SJ, Taylor KP, Ashby MJ, Brown MJ. The spironolactone, amiloride, losartan, and thiazide (SALT) double-blind crossover trial in patients with low-renin hypertension and elevated aldosterone-renin ratio. Circulation. 2007 Jul 17;116(3):268-75. Epub 2007 Jul 2.

Koskelainen J, Turpeinen T, Lehto H, Lammintausta R. Metabolic effects of hydrochlorothiazide and hydrochlorothiazide-amiloride and trichlormethiazide- triamterene combinations. Current Therapeutic Research 1985;17:554-564.

Laffer CL, Elijovich F, Eckert GJ, Tu W, Pratt JH, Brown NJ. Genetic variation in CYP4A11 and blood pressure response to mineralocorticoid receptor antagonism or ENaC inhibition: an exploratory pilot study in African Americans. J Am Soc Hypertens. 2014 Jul;8(7):475-80.

Matthesen SK, Larsen T, Vase H, Lauridsen TG, Jensen JM, Pedersen EB. Effect of amiloride and spironolactone on renal tubular function and central blood pressure in patients with arterial hypertension during baseline conditions and after furosemide: a double-blinded, randomized, placebo-controlled crossover trial. Clin Exp Hypertens. 2013;35(5):313-24.

Saha C, Eckert GJ, Ambrosius WT, Chun TY, Wagner MA, Zhao Q, Pratt JH. Improvement in blood pressure with inhibition of the epithelial sodium channel in blacks with hypertension. Hypertension. 2005 Sep;46(3):481-7. Salmela PI, Juustila H, Kinnunen O, Koistinen P. Comparison of low doses of hydrochlorothiazide plus amiloride and hydrochlorothiazide alone in hypertension in elderly patients. Ann Clin Res. 1986;18(2):88-92.

Stears AJ, Woods SH, Watts MM, Burton TJ, Graggaber J, Mir FA, Brown MJ. A double-blind, placebo-controlled, crossover trial comparing the effects of amiloride and hydrochlorothiazide on glucose tolerance in patients with essential hypertension. Hypertension. 2012 May;59(5):934-42.

SPIRONOLACTONE

Carey RM, Douglas JG, Schweikert JR, Liddle GW. The syndrome of essential hypertension and suppressed plasma renin activity. Normalization of blood pressure with spironolactone. Arch Intern Med. 1972 Dec;130(6):849-54.

Clement DL. Effect of spironolactone on systemic blood pressure, limb blood flow and response to sympathetic stimulation in hypertensive patients. Eur J Clin Pharmacol. 1982;21(4):263-7.

Cranston WI, Juel-Jensen BE. The effects of spironolactone and chlorthalidone on arterial pressure. Lancet. 1962 Jun 2;1(7240):1161-4.

Davies J, Gavin A, Band M, Morris A, Struthers A. Spironolactone reduces brachial pulse wave velocity and PIIINP levels in hypertensive diabetic patients. Br J Clin Pharmacol. 2005 May;59(5):520-3.

Hood SJ, Taylor KP, Ashby MJ, Brown MJ. The spironolactone, amiloride, losartan, and thiazide (SALT) double-blind crossover trial in patients with low-renin hypertension and elevated aldosterone-renin ratio. Circulation. 2007 Jul 17;116(3):268-75. Epub 2007 Jul 2.

Johnston LC, Grieble HG. Treatment of arterial hypertensive disease with diuretics. V. Spironolactone, an aldosterone antagonist. Arch Intern Med. 1967 Mar;119(3):225-31.

Laffer CL, Elijovich F, Eckert GJ, Tu W, Pratt JH, Brown NJ. Genetic variation in CYP4A11 and blood pressure response to mineralocorticoid receptor antagonism or ENaC inhibition: an exploratory pilot study in African Americans. J Am Soc Hypertens. 2014 Jul;8(7):475-80.

Leary WP, Asmal AC, Williams PC, Marwick B. Aldactone and acebutolol in treatment of hypertension. J Int Med Res. 1979;7(1):29-32.

Ramsay LE, Hettiarachchi J. Spironolactone in thiazide-induced hypokalaemia: variable response between patients. Br J Clin Pharmacol. 1981 Feb;11(2):153-8. Swaminathan K, Davies J, George J, Rajendra NS, Morris AD, Struthers AD. Spironolactone for poorly controlled hypertension in type 2 diabetes: conflicting effects on blood pressure, endothelial function, glycaemic control and hormonal profiles. Diabetologia. 2008 May;51(5):762-8.

Toner JM, Brawn LA, Yeo WW, Ramsay LE. Adequacy of twice daily dosing with potassium chloride and spironolactone in thiazide treated hypertensive patients. Br J Clin Pharmacol. 1991 Apr;31(4):457-61.

Vaclavik J, Sedlak R, Plachy M, Navratil K, Plasek J, Husar R, Kocianova E, Taborsky M. Addition of spironolactone in patients with resistant arterial hypertension (ASPIRANT)--study protocol. Hypertension 2011;57:1069-1075.

Weinberger MH, Roniker B, Krause SL, Weiss RJ. Eplerenone, a selective aldosterone blocker, in mild-to-moderate hypertension. Am J Hypertens. 2002 Aug;15(8):709-16.

Wolf RI, Mendlowitz M, Robos J, Styan GPH, Kornfeld P, Weigl A. Treatment of Hypertension with spironolactone: Double-blind study. JAMA 1966;198:121-127.

EPLERENONE

Calhoun DA, White WB, Krum H, Guo W, Bermann G, Trapani A, Lefkowitz MP, Ménard J. Effects of a novel aldosterone synthase inhibitor for treatment of primary hypertension: results of a randomized, double-blind, placebo- and active-controlled phase 2 trial. Circulation. 2011 Nov 1;124(18):1945-55.

Karns AD, Bral JM, Hartman D, Peppard T, Schumacher C. Study of aldosterone synthase inhibition as an add-on therapy in resistant hypertension. J Clin Hypertens (Greenwich). 2013 Mar;15(3):186-92.

Saruta T, Kageyama S, Ogihara T, Hiwada K, Ogawa M, Tawara K, Gatlin M, Garthwaite S, Bittman R, Patrick J. Efficacy and safety of the selective aldosterone blocker eplerenone in Japanese patients with hypertension: a randomized, double-blind, placebo-controlled, dose-ranging study. J Clin Hypert 2004; 6: 175-183.

Sica DA. Eplerenone and serum potassium change-relation to renal function. Am J Hypert 2003;16 (5): 100A.

Weinberger MH, Roniker B, Krause SL, Weiss RJ. Eplerenone, a selective aldosterone blocker, in mild-to-moderate hypertension. Am J Hypertens. 2002 Aug;15(8):709-16.

White WB, Carr AA, Krause S, Jordan R, Roniker B, Oigman W. Assessment of the novel selective aldosterone blocker eplerenone using ambulatory and clinical blood pressure in patients with systemic hypertension. Am J Cardiol. 2003 Jul 1;92(1):38-42

Table S1. Baseline gender, age, co-morbidities and background antihypertensive medications. % men, Background Author mean age Baseline conditions or comorbidities when specified BP meds Adherence3 Triamterene Kohvakka 19, 55 Exclusions: CHF, CAD, insulin dependent DM, CKD, liver disease Yes1 1 excluded Webb I 50, 50 NR Yes NM Webb II 67, 50 NR Yes NM Amiloride Chrysant 100, 51 Exclusions: CHF, recent MI, or recent stroke. Yes1 NM Hood 54, 60 Renin < 0.65 ng/mL/hr. Exclusions: secondary hypertension Mixed NM Koskelainen 53, 43 None mentioned Yes NM Laffer 53, 472 Renin < 2 ng/ml/hr Yes NM Matthesen 61, 45-70 Exclusions: diseases of the heart, lungs, and kidneys No NM Saha 53, 462 Plasma renin < 2 ng/ml/hr Yes 94%+ Salmela 30, 67 Exclusions: significant CHF, renal or liver disease Yes1 NM Stears 46, 65 None described Mixed NM Spironolactone Carey 36, 46 Exclusions: CKD, CHF, secondary HTN No NM Clement NR, NR None described No NM Cranston 70, 53 None described No NM Davies 70, 66 Diabetes type 2. Exclusions: CHF or liver failure No NM Hood 54, 60 Renin < 0.65 ng/mL/hr. Exclusions: secondary hypertension Mixed NM Johnston 23, 46 No comorbidities excluded. 24% with CHF, 30% with CKD No NM Laffer 53, 472 Renin < 2 ng/ml/hr Yes NM Leary 10, 28-63 None described No NM Matthesen 61, 45-70 Exclusions: diseases of the heart, lungs, and kidneys No NM Ramsay NR, NR No CHF, CKD, or liver failure Yes 93% Saha 53, 462 Plasma renin < 2 ng/ml/hr Yes NM Swaminathan NR, 63 Diabetes type 2. Exclusions: CHF, liver failure, recent hospitalization Yes1 NM Toner 67, 57 NR Yes “satisfactory” Vaclavik 62, 61 Resistant hypertension. Exclusions: CKD Yes1 “adequate” Weinberger 68, NR Exclusions: liver or valve disease, CKD, DM on insulin, CHF. No 96% Wolf None described No NM Eplerenone Calhoun 65, 55 Exclusions: cardiovascular disease, DM, CKD Yes NM Karns 63, 57 Exclusions: valvular dis, CHF, DM-1 (or poor control of Type 2), CKD Yes1 NM Saruta 69, 53 Most with low renin HTN. Exclusions: New York heart 2-4, CAD, CVA No NM Weinberger 68, NR Exclusions: liver or severe valve disease, CKD, DM, on insulin, CHF No 96% (method not specified) White 44, 53 Exclusions: CHF, CKD, liver disease, uncontrolled DM No 95%+ (method not specified) Rosignol NA Heart failure Yes NM CAD: coronary artery disease, CHF: congestive heart failure, CVA: stroke, MI: myocardial infarctions, CKD: chronic kidney disease, DM: diabetes mellitus, HTN: hypertension, NR: not reported 1Background medication included a diuretic. 2All patients of Black ethnicity. 3NM: not measured. Where measured, adherence was assessed by pill counts except where indicated.

Table S2. Features of data quality in trials comparing potassium sparing diuretics with placebo. Resting Losses to features Author (reference) Focus of study1 BP measurement BP Blinding2 follow up present3 Triamterene Kohvakka BP Trained nurses, sitting, after 10 minute rest, 5 measures, average of the last 3. Y Open NR 2 Webb I BP & Potassium Supine ? Double 11% 2 Webb II BP & Potassium Supine ? Double 9% 2 Amiloride Chrysant BP Supine after a 5 minute rest Y Double NR 3 Hood BP Sitting, 3 measurements ? Double 6% 2 Koskelainen Metabolic effects Supine ? Double NR 1 Laffer BP & ENAC Sitting, 3 morning measurements, average the last 2. ? Double NR 2 Matthesen BP 24 hour ambulatory blood pressure Y Double NR 3 Saha BP Sitting, 3 morning measurements, average the last 2. ? Double 12% 2 Salmela BP Supine after a 5 minute rest Y Double NR 3 Steaers Hyperglycemia Seated ? Double NR 1 Spironolactone Carey BP Supine after 10 minute rest, 3 measures averaged Y Double NR 3 Clement BP Sitting, 5 minute rest Y Double NR 3 Cranston BP Supine, 2 measures averaged ? Double NR 2 Davies BP & PWV “Sitting and rested”, average 3 measures averaged Y Double NR 3 Hood BP Sitting, 3 measurements ? Double 6% 2 Johnston BP Supine ? Open NR 1 Laffer BP % ENAC Sitting, 3 morning measurements, average the last 2. ? Double NR 2 Leary BP Supine after a 5 minute rest Y Single 3% 2 Matthesen BP, central BP, K 24 hour ambulatory blood pressure Y Double NR 3 Ramsay Potassium NR ? Open None 1 Saha BP Sitting, 3 morning measurements, average the last 2. ? Double 12% 2 Swaminathan BP & Endothelial fctn Sitting and rested. Average of 2 readings Y Double NR 3 Toner Potassium Not described ? Open NR 1 Vaclavik BP Sitting, 3 measures, average of the last 2. 5 minute rest. ? Double 6% 3 Weinberger BP Sitting after 5 minute rest. Repeated measures. Average of last 2 Y Double 2% 3 Wolf BP Supine ? Double NR 2 Eplerenone Calhoun BP Per published guidelines Y Double 10% 3 Karns BP Per British Hypertension Society Guidelines (2004) Y Single 19% 2 Saruta BP Not described ? Double 9% 2 Weinberger BP Sitting after 5 minute rest. Repeated measures. Average of last 2. Y Double 2% 3 White BP Sitting, 3 readings, average of the last 2 readings ? Double 11% 2 Rosignol K NA NA Double NR 2 BP: blood pressure, ENaC: epithelial sodium channel, NR: none reported, PWV: pulse wave velocity 1Important because studies focused on problems other than antihypertensive efficacy may have measured BP less accurately. 2Where blinding was not explicitly stated, the trial was assumed to be open. 3The sum of Focus of study on BP, Resting BP for 5 minutes, and Double Blinding. Table S3. Crossover trial (CO), duration of run in, washout period, time to measurement of BP or potassium (TTM), randomization (ran, yes=1), double blind (db, yes=1), follow up reported (f-u, yes=1), randomization described and appropriate (ran dscrbd, yes=1), double blinding described and appropriate (db dsccrbd, yes=1). Durations are in weeks. run wash- ran db Jadad Drug & author co in out TTM ran db f-u dscrb dscrbd score Triamterene Kohvakka y 5 0 13 1 0 1 0 0 2 Webb I Y 4 0 4 1 1 1 0 0 2 Webb II Y 4 0 4 1 1 1 0 0 2

Amiloride Chrysant n 6 na 4 1 1 0 0 0 2 Hood y 4 15 5 1 1 1 1 0 4 Koskelainen y 0 0 8 1 1 0 0 0 2 Laffer n 3 na 5 1 1 0 0 0 2 Matthesen y 2 2 4 1 1 1 1 1 5 Saha n 3 na 5 1 1 0 0 0 2 Salmela n 4 na 4 1 1 0 0 0 2 Steaers y 0 0 4 1 1 0 0 0 2

Spironolactone Carey y 4 6 6 1 1 0 0 0 2 Clement y 4 4 4 1 1 0 0 0 2 Cranston y 3 0 6 1 1 0 0 0 2 Davies y 0 4 16 1 1 0 0 0 2 Hood y 4 15 5 1 1 1 1 0 4 Johnston y 0 0 12 1 0 0 0 0 1 Laffer n 3 na 5 1 1 0 0 0 2 Leary y 2 0 8 1 0 0 0 0 1 Matthesen y 2 2 4 1 1 1 1 1 5 Ramsay y 0 0 4 1 0 0 0 0 1 Saha n 3 na 5 1 1 0 0 0 2 Swaminathan y 0 2 4 1 1 1 0 0 3 Toner n 0 na 5 1 0 0 0 0 1 Vaclavik n 0 na 8 1 1 1 1 1 5 Weinberger n 4 na 8 1 1 1 1 0 4 Wolf y 0 0 6 1 1 0 0 0 2

Eplerenone Calhoun n 4 na 8 1 1 1 1 1 5 Karns n 0 na 8 1 0 1 0 0 2 Saruta n 2 na 8 1 1 1 0 0 3 Rossignol n 0 na 60 1 1 0 0 0 2 Weinberger n 4 na 8 1 1 1 1 0 4 White n 3 na 12 1 1 1 0 0 3

Table S4. Examination of trial features as predictors of office systolic blood pressure. Only predictors with P < 0.05 are shown. TRIAL DRUG AMIL SPIR EPLER EPLER (24hr ) AMIL & EPLER AMIL & SPIR SPIR & EPLER SPIR, AMIL & EPLER Parameter P R2 P R2 P R2 P R2 P R2 P R2 P R2 P R2 Blacks 0.034 33 NA NA NA NA % men NA NA Background meds* 0.002 77 NA NA 0.001 70 ACE or ARB NA NA NA NA Baseline SBP 0.027 5 Focus on BP NA NA NA NA NA NA 0.033 14 Crossover trial NA NA NA NA 0.024 5 Double blind trial NA NA Log Dose 0.002 73 0.002 69 0.004 0.002 56 0.002 31 0.004 23 Lo renin HTN 0.015 52 NA NA NA NA Resistant HTN NA NA NA NA BP focus & resting 0.028 51 0.012 53 0.011 41 0.002 61 0.001 47 <0.001 45 Weeks followed HTN: hypertension, NA: not applicable due to the covariate being identical for all trials. R2: Percent of total between-study variability explained. ACE or ARB: Angiotensin converting enzyme inhibitor or angiotensin receptor blocker, EPLER (office): Eplerenone with office SBP as the outcome. EPLER (24 hr): Eplerenone with 24 hour as the outcome. AMIL: amiloride, SPIR: spironolactone, SBP: systolic blood pressure *Background antihypertensive medications.

Table S5. Examination of trial features as predictors of serum potassium. Only predictors with P values < 0.05 are shown. TRIAL DRUG AMIL SPIR AMIL & SPIR Parameter P value R2 P value R2 P value R2 Trial characteristic % Men NA NA Age Blacks 0.002 100 Background Meds* NA ACE or ARB NA Baseline K NA Crossover trial 0.005 100 0.012 62 Log Dose 0.009 100 0.002 100 <0.001 100 Double blind Low renin hypertension Resistant hypertension NA Weeks Followed *Background antihypertensive medications. R2: Percent of total between-study variability explained. ACE or ARB: Angiotensin converting enzyme inhibitor or angiotensin receptor blocker, AMIL: amiloride, SPIR: spironolactone.

Figure S1. Of the 46 randomized comparisons with office systolic BP as the outcome, it was necessary to read 25 standard errors and 6 mean systolic BPs from the articles’ enlarged graphs. (See procedure in Box above.) Out of 15 instances where both graphic and tabular data were available, precision in reading BPs from graphs was tested for authors, GR and SY, who were blind to each other and to tabular data. To the nearest thousandth, the correlation coefficient was 1.000 for each of 3 comparisons: GR versus tabular data, SY versus tabular data, and GR versus SY, indicating near perfect precision.

Keywords below applied to PubMed, Cochrane, & EMBASE thru May 2015. N=3,668

Duplicates

N = 2,174

Removed based on titles and abstracts

N=2,025

Removed based on full text articles

N=28

Figure S2. PRISMA flow diagram for systematic review of potassium sparing diuretics. Keywords and algorithm for this systematic review were triamterene (exploded) or amiloride (exploded) or eplerenone (exploded) or spironolactone (exploded).

See text for inclusion and exclusion criteria.

Figure S3. Placebo adjusted dose response for eplerenone with 24 hour ambulatory blood pressure as the outcome. The model explained 100% of the between-study variability with a P for fit of 0.995

Figure S4. Dose stratified meta-analyses.

Figure S5. Sensitivity analysis from removing each trial in the random effects model.