Antihistamines in daily practice: Italian allergologists' opinion.

Anti-histamines represent the mainstay of the treatment of allergic rhinitis and urticaria (1-2). However, as in every chronic condition, adherence to the therapy is relevant and a regular long-term use is more effective than an use on demand in both these conditions (3). The present survey investigated doctors’ opinions about the use of antihistamines, and looked for criticisms and unmet needs that may affect their regular use and, hence, adherence to therapy (4). A total of 147 Italian allergoloists answered a web questionnaire, structured in 9 items, from April to September 2011. Filled forms were evaluated by the beginning of October 2011. Using a Visual Analogue Scale (VAS) participants were asked to score the relevance of different pharmacological properties of antihistamines, including safety, rapidity of onset of action, and practicality.With the same tool (VAS) different drug formulations for daily use were investigated. Most respondents prescribed only (58%) or mainly (42%) second generation anti-histamines. All the studied features were considered highly important for long term use, although safety (9.0) scored slight higher than onset of action (8.2) and practicality (8.2). Fast dissolving tablets (8.8) and tablets (8.2) were considered more suitable than drops (7.0) or spray (5.2). Seventy one (71%) of participants disregarded the difficulty in swallowing the tablet as a fairly small problem, as, according to their opinion, not more then 20% of patients complained about this. Nevertheless, many allergists (45%) considered an oral dissolving tablet the most suitable form for daily usage and 68% believed that this formulation may also have a quicker onset of action. One third (32%) considered such formulation an important factor to improve the adherence to the treatment, being suitable for all ages according to 72% of allergologists. Finally, 55% consider a lyophilized formula particularly useful in the management of acute conditions, such as exacerbations of allergic rhinitis, acute urticaria or anaphylaxis. Adherence to the treatment plays a crucial role in successful long term therapy (4). Although education and a good doctor-patient relationship are important, other factors, such as an easy schedule and drug formulation, cannot be considered trivial. In fact, a better compliance has been recorded when drugs are administered once rather than twice or several times daily (5). In this study most specialists prescribed second generation anti-histamines, being these drugs less sedating, better tolerated, and generally administered once/daily. Swallowing difficulties were underestimated by most participants; in fact, according to other studies, 26% to 52% of patients have problems in swallowing oral drug formulations (tablets, capsules) (6, 7), and 50% fail to take medication when no water is available (7). Although the belief that fast dissolving tablets have a quicker onset of action is not supported by clear evidence (7), such formulations can be suggested to very young, elderly, or bed ridden patients, and to busy or travelling patients as well. In conclusion, the availability of different forms of antihistamines represents an opportunity to chose the most suitable formulation for each patient. This may enhance the adherence to the treatment and therefore its outcome; thus being cost-effective in the long term.