Omeprazole 10 mg or 20 mg once daily in the prevention of recurrence of reflux oesophagitis. Solo Investigator Group.

This study determined the optimal maintenance dose of omeprazole in reflux oesophagitis. One hundred and ninety three patients rendered asymptomatic and healed after four or eight weeks omeprazole were randomised double blind to 10 mg omeprazole once daily (n = 60 evaluable), 20 mg omeprazole once daily (n = 68), or placebo (n = 62) for one year or until symptomatic relapse. Each omeprazole regimen was superior to placebo in preventing both symptomatic relapse (life table analysis, p < 0.001) and endoscopically verified relapse (p < 0.001). At 12 months, the life table endoscopic remission rates (proportions of patients without grade > or = 2 oesophagitis) were: 50% (95% confidence intervals 34 to 66%) with 10 mg omeprazole once daily, 74% (62 to 86%) with 20 mg omeprazole once daily, and 14% (2 to 26%) with placebo. At 12 months, the life table symptomatic remission rates (proportions of patients asymptomatic or with mild symptoms) were: 77% (64 to 89%) with 10 mg omeprazole once daily, 83% (73 to 93%) with 20 mg omeprazole once daily, and 34% (16 to 52%) with placebo. Both 10 mg and 20 mg omeprazole once daily were effective in prolonging the remission of reflux oesophagitis: 10 mg may be appropriate to start longterm treatment, though the existence of a dose response relation means that 20 mg once daily may be effective in patients for whom 10 mg once daily is suboptimal.

Does 40 mg omeprazole daily offer additional benefit over 20 mg daily in patients requiring more than 4 weeks of treatment for symptomatic reflux oesophagitis?

This study was designed to establish whether 40 mg omeprazole once daily exhibits sufficient additional efficacy over that of 20 mg omeprazole once daily in patients with symptomatic reflux oesophagitis requiring more than an initial 4-week course of 20 mg omeprazole once daily (o.m.) to warrant routine use of the higher dose. Three hundred and thirteen patients were randomized to receive either 20 mg omeprazole (4 weeks) then 20 mg (second 4 weeks if not both healed and symptom-free after 4 weeks), or 20 mg omeprazole (4 weeks) then 40 mg omeprazole o.m. (second 4 weeks). One hundred and twenty-seven patients were healed and symptom-free after 4 weeks and left the study at that point. Taking the second treatment period in isolation, the healing rate (64% vs. 45%, P < 0.02) and relief of heartburn (72% vs. 60%, P < 0.002) were greater among patients receiving 40 mg omeprazole o.m., demonstrating the existence of a dose-response relationship for omeprazole. However, on completion, there were no significant differences between the patients randomized to the 20/20 mg (healed 65%, asymptomatic 69%) or the 20/40 mg (healed 74%, asymptomatic 74%: both not significant differences compared with 20/20 mg) regimens. The magnitude of the difference in efficacy between 20 and 40 mg omeprazole in symptomatic reflux oesophagitis is insufficient to warrant the routine use of 40 mg in patients requiring more than 4 weeks' treatment with 20 mg omeprazole o.m.; continued treatment with 20 mg omeprazole for 4-8 weeks is the preferred option.

Isolation of cDNA coding for an ubiquitous membrane protein deficient in high Na+, low K+ stomatocytic erythrocytes.

Human red blood cells (RBCs) that are deficient in an integral membrane-associated protein ("stomatin") of apparent molecular mass 31 Kd show a catastrophic increase in passive membrane permeability to the univalent cations Na+ and K+ and are stomatocytic in shape. We have purified this protein from normal RBC membranes and isolated a cDNA clone coding for it. The deduced protein sequence is unrelated to that of any known ion-transport-related protein. Selective solubilization studies using detergents show that while the protein is strongly associated with the phospholipid bilayer, it also binds to the cytoskeleton. The predicted polypeptide has a single trans-membranous hydrophobic segment near the N-terminus, which would locate it in the membrane; the large C-terminal domain is hydrophilic and cytoplasmic in orientation and is presumed to be responsible for the attachment to the cytoskeleton. By inference, the protein has the function of closing a latent ion channel. The messenger RNA encoding this protein is ubiquitously distributed in different human cell types and tissues and is thus presumably a widely distributed regulator of transmembrane cation fluxes. As a membrane-bound inhibitor protein of Na+ and K+ transport, it is unique among the known components of membrane-transport proteins.