Patients have treatment preferences: a multicentre, double-blind, crossover study comparing rabeprazole and...

It is increasingly common practice to change patients from one medication in a drug class to another, often as part of a general formulary change. The underlying assumption and accepted wisdom is that all compounds within a class are identical. To our knowledge, there has been no published investigation into the patients' views on such changes or on the individual medications. These views may be affected by positive side-effects, not normally sought in clinical trials, as well as negative side-effects, which are always reported. The objectives of this study were to determine whether patients whose primary symptoms were already controlled by a proton pump inhibitor (PPI) could distinguish between rabeprazole and omeprazole; to determine the incidence of positive, as well as negative, side-effects; to elicit patients' opinions on changing medication within a class, and on the importance of certain characteristics of medication. The design was a double-blind, double-dummy, randomised, crossover trial, set in five general practice research centres in the UK and Ireland. 240 eligible patients were randomised to receive daily treatment, first for 4 weeks with omeprazole 20 mg/day, and then for reverse order. Each phase of 4 weeks was separately assessed by patients through questionnaires and by non-directed questioning about positive and negative side-effects. At the end of the 8 weeks, patients compared the two medications in seven treatment characteristics. Patients were further asked their attitude to changing medication within a class. Data were collected by a web-based electronic data capture system. Results showed that the majority of patients could be switched to another PPI therapy, predictably without noticeable difference in maintenance of primary symptom control. About one-quarter to one-half of patients were able to express a preference for one or other of the treatments dependent on the variable assessed. For 'absence of unwanted side-effects' and 'presence of positive side-effects' a statistically significant difference in favour of rabeprazole was detected (p = 0.0467 and p = 0.0188, respectively). In terms of the total treatment preference score, the primary outcome variable, there was no statistically significant difference between the two PPIs (p = 0.0754). This finding is mainly attributable to the two PPIs providing similar relief of primary mask the findings for the other variables assessed. However, there were numerically more patients (10 vs. 3) who reported 'marked' positive side-effects on rabeprazole. On direct questioning, patients indicated that tablets (rabeprazole) were more easily swallowed than capsules (omeprazole) (p < 0.0001), but less easily handled than capsules (p = 0.0003). These analyses may however have been confounded by the fact that the omeprazole medication had to be over-encapsulated to allow blinding for this double-dummy, blinded study. There was no difference in tolerability between rabeprazole and omeprazole, with 52.6% and 51% of patients reporting at least one adverse event, respectively. Of the patients controlled and maintained on omeprazole before the study, 33.9% reported adverse events on omeprazole during the study and seven discontinued the study for that reason. Patients thought the most important drug characteristics for treating this condition were rapid and lasting control of pain. Most (83.6%) would be willing to try an alternative medication within a drug class. In conclusion, most patients already controlled by a PPI would be willing to try another. An individual patient may have a strong preference for one PPI over another, and this difference may be important if treatment is to be long term.