Medication adherence during laboratory workup for primary aldosteronism: pilot study

Figures & data

Table 1 Patient characteristics and prescribed medication on the first and second visits (mean ± SD); n=24

Age (years)	54±13
Female (%)	42
Body weight (kg)	82±22
eGFR (mL/min/1.73 m^2)	81±24
Prescribed medication	First visit	Second visit
Number of pills taken, any reason	5.2±3.6	3.8±3.1
Antihypertensive drugs per patient	3.2±1.1	1.1±0.7
Number of antihypertensive pills/patient	2.5±1.0	1.1±0.7
ARB/ACE inhibitors (%)	83	0
β-blockers (%)	54	0
Ca-antagonists (%)	88	83
Diureticsa (%)	67	0
α-adrenoceptor blocker (%)	21	25
Moxonidine (%)	8	0

Note:

a Thiazide-like, amiloride, loop diuretics.

Abbreviations: ACE, angiotensin converting enzyme; ARB, angiotensin receptor blocker; eGFR, estimated glomerular filtration rate.

Table 2 Screened drugs, prescription frequencies, and corresponding plasma drug results (n=24)

Drugs	Compatible on second visit	Dose range (mg/day)	First visit			Second visit
			Prescriptions	Test positive, prescribed	Test positive, not prescribed	Prescriptions	Test positive, prescribed	Test positive, not prescribed
Not assayed (n=8)a			19	–	–	6	–	–
Assayed (n=10)			60	54	3	20	20	7
Amlodipine	Yes	5–10	15	15	0	16	16	1
Lercanidipine	Yes	10–20	6	5	1	4	4	1
Candesartan	No	16–32	2	1	0	0	–	0
Irbesartan	No	150	1	1	0	0	–	0
Olmesartan	No	20	1	1	0	0	–	0
Valsartan	No	160–320	8	8	0	0	–	0
Perindoprilb	No	2.5–10	3	3	0	0	–	2
Hydrochlorothiazide	No	6.25–50	12	11	0	0	–	0
Metoprolol	No	25–100	9	7	1	0	–	2
Nebivolol	No	2.5–5.0	3	2	1	0	–	1

Notes:

a Azilsartan, lisinopril, carvedilol, torasemide, indapamide, amiloride, moxonidine, doxazosine;

b analysis of perindoprilat.

Table 3 Nonadherence and unreported drug use among study participants according to plasma drug screening

Parameter	First visit	Second visit
Patients on antihypertensives, n (%)	24 (100.0)	18 (75.0)
Nonadherence, n (%, 95%CI)	8 (33.3; 18.0–53.3)	6 (25.0; 12.0–44.9)
Missing intake, n (%, 95%CI)a	5 (20.8; 9.2–40.5)	0 (0; 0–13.8)
Unprescribed drug use, n (%, 95%CI)^b	3 (12.5; 3.3–33.5)	6 (25.0; 12.0–44.9)

Notes:

a ≥1 prescription not detected in plasma.

b≥ 1 drug detected in plasma without a corresponding prescription.

Figure 1 Plasma concentrations of antihypertensive drugs on the first and second visits expressed as ratios with expected peak concentrations (C_max, 100%); logarithmic representation.

Notes: Only prescriptions confirmed in plasma are shown. Solid circles indicate results ≥expected C_min and empty circles indicate results <expected C_min. Expected mean C_max (highest/lowest daily dose) and C_min values (% C_max) were as follows: per 36.4/15.1 ng/mL (7%/5%); can 234 ng/mL (28%); irb 2,040 ng/mL (5%); olm 507 ng/mL (4%); val 5,550/3,940 ng/mL (18%/3%); aml 17.5/10.5 ng/mL (79%/57%); ler 7.7/3.3 ng/mL (5%/1%); met 53.5/11.2 ng/mL (70%/24%); neb 1.5 ng/mL (7%); hct 260/70 ng/mL (14%/9%).
Abbreviations: aml, amlodipine; can, candesartan; hct, hydrochlorothiazide; irb, irbesartan; olm, olmesartan; per, perindopril; val, valsartan; ler, lercanidipine; met, metoprolol; neb, nebivolol.