The eternal triangle: benefit, risk, and cost of therapeutic agents.

Some people can undoubtedly tolerate a first-generation H1-receptor antagonist without sedation or other CNS adverse effects, but others cannot. There is no rapid, reliable way of differentiating these two populations. A history of presence or absence of subjective somnolence from one H1-receptor antagonist is not necessarily reliable and has no consistently useful predictive value for subsequent experience with other H1-receptor antagonists. As H1-receptor antagonists are used primarily to treat non-life-threatening disorders, safety should be a prime consideration in selecting one for use, and is surely as important a concern as efficacy and low cost. If your pilot is not permitted to take these medications before going to work, why should your taxi driver, your child's school bus driver, your dentist, your nurse, or your office assistant, to name a few examples, be allowed to do so? When the broad issue of safety is considered, first-generation H1-receptor antagonists may not be as cost-effective as they appear to be. The inherent benefit of any medication is inextricably linked with the inherent risk. It is incumbent on those promulgating the use of the older H1-receptor antagonists to define these benefits and risk further. Lowering the cost of the second-generation, relatively nonsedating H1-receptor antagonists so they are no longer the most expensive medications used in treatment of allergic rhinitis would also help solve the problem of the eternal triangle as it pertains to therapeutic use of H1-receptor antagonists.