Terapia com inibidor da ECA com dosagens relativamente altas e risco de agravamento renal na insuficiência cardíaca crônica / ACE-inhibitor therapy at relatively high doses and risk of renal worsening in chronic heart failure

FUNDAMENTO: O efeito renoprotetor dos inibidores da ECA vem sendo questionado no caso de diminuição do volume circulante efetivo, como na insuficiência cardíaca crônica direita ou biventricular. Objetivo: Detectar os preditores clínicos de agravamento renal na população de pacientes com ICC, caracterizado por dois tipos de regime de dosagem de inibidores da ECA. MÉTODOS: De acordo com um desenho de coorte retrospectiva, seguimos dois grupos de pacientes com ICC - tanto direita quanto biventricular -, todos na classe III da NYHA, tratados com inibidores da ECA (enalapril ou lisinopril), e com fração de ejeção do ventrículo esquerdo (FEVE) < 50 por cento, por meio de distinção em sua dosagem de inibidor da ECA: média-baixa (< 10 mg por dia) ou dosagem "alta" (> 10 mg por dia) de enalapril ou lisinopril. A disfunção renal agravada (ARD) foi definida pelo aumento de Cr > 30 por cento com relação ao segmento basal. O modelo de risco proporcional de Cox foi utilizado para identificar os preditores da ARD entre as seguintes variáveis: os inibidores da ECA com "alta" dosagem, idade, FEVE basal, histórico de repetidas terapias intensivas com diuréticos de alça por via intravenosa (diurético intravenoso), diabete, Cr basal, histórico de hipertensão, pressão arterial sistólica < 100 mmHg. RESULTADOS: Cinquenta e sete pacientes foram recrutados, dos quais 15 foram tratados com inibidor da ECA com dosagem "alta". Durante um seguimento médio de 718 dias, a ARD ocorreu em 17 pacientes (29,8 por cento). Apenas o inibidor da ECA com "alta" dosagem (RR: 12,4681 IC: 2,1614 - 71,9239 p = 0,0050) e Cr basal (RR:1,2344 IC: 1,0414 - 1,4632 p = 0,0157) foi demonstrado ser preditor da ARD. Além disso, demonstrou-se que o inibidor da ECA com dosagens "altas" não previu ARD em ICC sem diurético intravenoso e ICC com diabete. CONCLUSÃO: Na ICC de classe III da NYHA, o inibidor da ECA com "altas" dosagens e um maior Cr basal foi preditor da ARD. A nefrotoxicidade relacionada com inibidores da ECA em "altas" dosagens foi aumentada com o diurético intravenoso, ao passo que, em pacientes com ICC com diabete, aquela não foi detectada.

BACKGROUND: Renoprotective effect of ACE-inhibitors has been questioned in case of decreased effective circulating volume, like in right or biventricular chronic heart failure. OBJECTIVE: To detect clinical predictors of renal worsening in CHF patient population characterized by two types of ACE-inhibitor dosing regimens. METHODS: According to a retrospective cohort design, we followed 2 groups of patients with CHF - whether right or biventricular -, all in III NYHA class treated with ACE-inhibitors (enalapril or lisinopril), and with left ventricular ejection fraction (LVEF) < 50 percent, by distinguishing them by ACE-inhibitor dosing: average-low (<10 mg per day) or "high" dose (>10 mg per day) of enalapril or lisinopril. Worsened renal failure (ARD) was defined by Cr increase >30 percent from baseline. Cox proportional hazards model was used to identify the predictors of ARD among the following variables: ACE-inhibitors "high" dose, age, basal LVEF, history of repeated intensive intravenous loop diuretic therapies (IV diur), diabetes, basal Cr, history of hypertension, systolic blood pressure < 100 mm Hg. RESULTS: 57 patients were recruited, of whom 15 were treated with ACE-inhibitor "high" dose. During a mean follow-up of 718 days, ARD occurred in 17 (29.8 percent) patients. Only ACE-inhibitor "high" dose (HR: 12.4681 C.I.: 2.1614-71.9239 p=0.0050) and basal Cr (HR: 1.2344 C.I.: 1.0414-1.4632 p=0.0157) were shown to predict ARD. Moreover, ACE-inhibitor "high" doses were shown to fail to predict ARD in both CHF without IV diur and CHF with diabetes. CONCLUSION: In III NYHA class CHF, ACE-inhibitor "high" doses and a higher basal Cr predicted ARD. Nephrotoxicity related to ACE-inhibitor "high" doses was increased by IV diur, whereas it was not detected in CHF patients with diabetes.

Colorimetric microdetermination of enalapril maleate in pharmaceuticals and spiked biological fluids using redox reactions

Five simple, sensitive, rapid, and reproducible procedures [A-E] for microdetermination of enalapril maleate in pharmaceuticals and biological fluids are investigated. Procedures A and B are based on oxidation of enalapril maleate by Fe[3+] in the presence of bipyridyl [bipy] or o-phenanthroline [o-phen]. The formations of tris-complex upon the reaction with Fe[3+]-bipy and/or Fe[3+]-o-phen mixture in optimum conditions were demonstrated. Procedure C is based on the oxidation of enalapril by N-bromosuccinimide [NBS] and determination of the unreacted NBS by measuring the decrease in absorbance of amaranth dye [AM] at 520 nm. Procedures D and E include the addition of excess Ce[4+] and the determination of the unreacted oxidant by the decrease of the red color of chromotrope 2R [C2R] at 527 nm for method D or the decrease of the orange pink color of rhodamine 60 [R6G] at 524 nm for method E. Regression analysis of Beer's plots showed good correlation iii the concentration ranges 0.2-5.75 micro g ml[-1], whereas optimum concentration ranges applying Ringbom method were 0.4-5.6 micro g ml[-1]. The apparent molar absorptivity, Sandell sensitivity, detection and quantification limits were calculated. The developed procedures were applied successfully for the determination of enalapril maleate without interference from common excipients in pharmaceuticals and biological fluids