RESUMO
BACKGROUND AND AIMS: Carvedilol has emerged as the preferred ß-blocker for treating portal hypertension. However, there is still a debate in dosing regimen, with a potential lower bioavailability in once-daily regimens. The aim of this study is to assess the acute effects of carvedilol posology in patients with clinically significant portal hypertension (CSPH), as a surrogate marker of bioavailability. METHODS: In this experimental study, 34 patients with CSPH receiving carvedilol twice daily were asked to suppress the night dose of carvedilol, creating a standardized 24-hour dose interval. Spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) by transient elastography (TE) were performed, with the exact interval between the last carvedilol administration and TE measurements consistently maintained at 24 hours and compared with values prior and under treatment. RESULTS: Thirty-four patients were included, predominantly male (82.9%). SSM after suspending carvedilol for 24 hours [mean, 73.9kPa (SD, 17.0)] was significantly higher ( P < 0.001) than under treatment [mean, 56.3kPa (SD, 13.2)] and was not significantly different ( P = 0.908) from SSM prior to introduction of carvedilol [mean, 74.5kPa (SD, 12.4)]. Differences were also found in stratified analysis for carvedilol dosage, D'Amico classification stages, MELDNa scores, MELD3.0 scores, Child-Pugh class A and CSPH due to alcoholic cirrhosis. LSM after suspension was not significantly different from both under treatment and prior to treatment. CONCLUSION: The differences in SSM after skipping one dose of carvedilol show both the importance of strict adherence to the prescribed dosing regimen to achieve the expected therapeutic benefits and the impact of twice daily prescription in bioavailability throughout the day.