Terfenadine is the first of a new class of non-sedating H1 antihistamines. It differs from chlorpheniramine in its lower anticholinergic activity in rabbit salivation tests. In animal model distribution studies, the drug is not found in the brain. In most clinical studies sedation attributed to terfenadine was on the order of that observed with placebo. Clinical trials of efficacy show that at best terfenadine is slightly less effective than or as effective as chlorpheniramine.

Animals↗

PubMedDate not supplied

An immunoperoxidase method for the demonstration of allergen-specific IgE in serum.

A solid-phase immunoenzymatic technique for the detection of allergen-specific IgE antibodies in serum is described. The binding of such antibodies to allergen insolubilized on cyanogen bromide-activated paper discs was detected by a subsequent two-step procedure involving the use of rabbit antihuman IgE and goat antirabbit IgG coupled with peroxidase. A solution of 3-3' diaminobenzidine and hydrogen peroxide, employed as the color indicator system, turned the discs dark brown in positive cases. Discs carrying 11 different inhalant allergens were tested with sera containing allergen-specific IgE antibodies. Agreement between the results of this technique and the RAST was seen in 85% of 310 tests performed. In the clinical practice of otorhinolaryngologic allergy, this test may prove to be an important laboratory adjunct ot clinical history and diagnostic skin test in the identification of the incriminated inhalant allergens.

Allergens↗

PubMedDate not supplied

Methods of studying antihistamines.

A variety of ingenious methods have been devised to challenge and incite episodes of acute allergic rhinitis in susceptible individuals. These methods teach us much about basic mechanisms involved in the disease. There is some danger in using them for efficacy trials because antihistamines are only partially effective treatment for hay fever and the challenge administered could easily overcome the degree of protection. Additional studies may lead to a better understanding of the factors involved in challenges and hence, their usefulness in clinical testing. The out-patient trial design is successful in demonstrating efficacy in 40 to 60 per cent of trials. The field trial is 70 to 90 percent accurate in its findings. The clinical design of antihistamine trials has improved remarkably in the past 10 years. Because of the nature of the disadvantages discussed throughout this report, I would doubt that further improvements in design will occur in future years unless a substitute is found for subjective evaluations.

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