Vonoprazan more potent than rabeprazole for acid suppression

Vonoprazan at a dosing schedule of 20 mg once daily possesses a more potent and durable acid suppression capabilities relative rabeprazole at 10 or 20 mg twice daily, in addition to a pharmacodynamic profile that makes it useful for inducing early mucosal healing in reflux oesophagitis, according to a study.

Researchers evaluated the acid‐inhibitory effect of vonoprazan 10/20 mg once‐daily (OD; V10/V20) vs rabeprazole 10/20 mg twice‐daily (BID; R20/R40) in three cohorts of 10 healthy Japanese adults. Volunteers in each cohort were randomized to receive V or R for 7 days and then crossed over to the other treatment for another 7 days after a washout period of ≥7 days.

All participants underwent 24‐hours multichannel gastric impedance‐pH monitoring on day 6 of each treatment period. Primary pharmacodynamic endpoints were percent times pH ≥3, ≥4 and ≥5 (pH 3, 4 and 5 holding time ratios [HTRs]) in 24 hours.

V20 exerted a more favourable acid‐inhibitory effect (24‐hour pH 3 HTR) compared with R20 (91.0 percent vs 65.3 percent; p=0.0049) and R40 (98.5 percent vs 85.9 percent; p=0.0073). Results were similar for 24‐hour pH 4 and 5 HTRs.

Compared with R40, V20 also achieved superior nocturnal pH 4 (91.5 percent vs 73.2 percent; p=0.0319) and 5 HTRs (78.8 percent vs 62.2 percent; p=0.0325).

One participant developed diarrhoea while receiving R40, and this was the only adverse event considered treatment‐related.

Despite its potent acid‐inhibitory effect, long‐term use of vonoprazan should be carefully considered as it can lead to sustained hypergastrinemia, which may promote neuroendocrine tumours, according to the researchers.