RESUMEN
BACKGROUND: Non-adherence to antihypertensives is a cause of 'pseudo-treatment-resistant' hypertension. OBJECTIVE: To determine whether monitoring plasma amlodipine concentrations and inhibition of angiotensin-converting enzyme (ACE) can be adjunct adherence tools. METHODS: Patients with hypertension who were prescribed enalapril and amlodipine were enrolled. Blood pressures (BPs) were monitored and an adherence questionnaire was completed. Steady-state amlodipine was assayed using liquid chromatography-mass spectrometry and degree of ACE inhibition using the Z-FHL/HHL (z-phenylalanine-histidine-leucine/hippuryl-histidine-leucine) ratio. RESULTS: One hundred patients (mean (standard deviation) age 50.5 (12) years, 46% male) were enrolled. Based on plasma assays, 26/97 patients (26.8%) were unsuppressed by enalapril and 20/100 (20%) were sub-therapeutic for amlodipine. There were significant BP differences based on plasma levels of the medication: 21/20 mmHg lower in the group with suppressed ACE and 26/20 mmHg in the group with steady-state amlodipine concentrations. CONCLUSIONS: Monitoring antihypertensive adherence by assaying plasma medication concentrations is a feasible option for evaluating true v. pseudo-resistant hypertension.
RESUMEN
BACKGROUND: Methamphetamine abuse has risen dramatically in South Africa. The chronic effects of abuse on the kidneys and blood pressure have not been documented. This study reviewed patients referred for evaluation of kidney disease and/or hypertension, who had been abusing methamphetamines. METHODS: The records of patients referred to the renal unit between 2005 and 2013 who had been using methamphetamines were retrospectively reviewed. Patient demographics, biophysical parameters, blood pressure, renal function, renal ultrasound and biopsy findings, complications of chronic kidney disease and comorbidities were recorded. RESULTS: Forty-seven patients were included in the study. Their mean age was 29 years. Hypertension was present in 42 (89.4%) of patients, with malignant hypertension in 21 (44.7%). Forty-five (95.7%) had chronic kidney disease (CKD), and 26 (55.3%) had end-stage renal disease. Renal biopsies were performed in 24 patients. Twelve (50.0%) of the biopsies showed hypertensive changes and 14 (58.3%) mesangiocapillary glomerulonephritis type 1, with deposition of IgM and C3 complement. CONCLUSION: Methamphetamine use is associated with severe hypertension, mesangiocapillary glomerulonephritis and CKD.