A trial of type 12 purinergic (P2Y12) receptor inhibition with prasugrel identifies a potentially distinct endotype of patients with aspirin-exacerbated respiratory disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is characterized by asthma, recurrent nasal polyposis, and respiratory reactions on ingestion of COX-1 inhibitors. Increased numbers of platelet-leukocyte aggregates are present in the sinus tissue and blood of patients with AERD compared with that of aspirin-tolerant patients, and platelet activation can contribute to aspirin-induced reactions. OBJECTIVE: We sought to determine whether treatment with prasugrel, which inhibits platelet activation by blocking the type 12 purinergic (P2Y12) receptor, would attenuate the severity of sinonasal and respiratory symptoms induced during aspirin challenge in patients with AERD. METHODS: Forty patients with AERD completed a 10-week, double-blind, placebo-controlled crossover trial of prasugrel. All patients underwent oral aspirin challenges after 4 weeks of prasugrel and after 4 weeks of placebo. The primary outcome was a change in the provocative dose of aspirin that would elicit an increase in Total Nasal Symptom Score (TNSS) of 2 points. Changes in lung function, urinary eicosanoids, plasma tryptase, platelet-leukocyte aggregates, and platelet activation were also recorded. RESULTS: Prasugrel did not significantly change the mean increase in TNSS of 2 points (79 ± 15 for patients receiving placebo and 139 ± 32 for patients receiving prasugrel, P = .10), platelet-leukocyte aggregates, or increases in urinary leukotriene E4 and prostaglandin D2 metabolite levels during aspirin-induced reactions in the study population as a whole. Five subjects (responders) reacted to aspirin while receiving placebo but did not have any reaction to aspirin challenge after the prasugrel arm. In contrast to prasugrel nonresponders (35 subjects), the prasugrel responders had smaller reaction-induced increases in TNSS; did not have significant aspirin-induced increases in urinary leukotriene E4, prostaglandin D2 metabolite, or thromboxane B2 levels; and did not display increases in serum tryptase levels during aspirin reactions on the placebo arm, all of which were observed in the nonresponders. CONCLUSION: In the overall study population, prasugrel did not attenuate aspirin-induced symptoms, possibly because it failed to decrease the frequencies of platelet-adherent leukocytes or to diminish aspirin-induced mast cell activation. In a small subset of patients with AERD who had greater baseline platelet activation and milder upper respiratory symptoms during aspirin-induced reactions, P2Y12 receptor antagonism with prasugrel completely inhibited all aspirin-induced reaction symptoms, suggesting a contribution from P2Y12 receptor signaling in this subset.

Effects of a single oral dose of gabapentin on storm phobia in dogs: A double-blind, placebo-controlled crossover trial.

BACKGROUND: Storm phobia in companion dogs is a common disorder that significantly impacts dogs' welfare. Gabapentin, the action of which is only partially understood, is widely used for its antiepileptic and analgesic properties. Only recently, the veterinary community began to use gabapentin to address phobia and anxiety in dogs. This study tested gabapentin to lower fear responses of dogs during a thunderstorm event. METHODS: Eighteen dogs suffering from storm phobia completed our double-blind, placebo-controlled crossover trial. Each dog's behaviour was evaluated twice by his owner: once under placebo, once under gabapentin. The treatment was orally administered at least 90 min before the exposure. Gabapentin was given at a dose ranging from 25 to 30 mg/kg. RESULTS: Our results indicate a significant reduction of the fear responses of dogs under gabapentin. The adverse effects were rare, and the most frequent amongst them was ataxia. CONCLUSION: In this trial, gabapentin appears to be an efficient and safe molecule that should be considered as part of the treatment plan of storm phobia in dogs.

A Randomized, Placebo-Controlled, Blinded, Crossover, Pilot Study of the Effects of Dextromethorphan/Quinidine for the Treatment of Neurobehavioral Symptoms in Adults with Autism.

Prior studies have demonstrated successful irritability treatment using dopaminergic antagonists in autistic patients. The purpose of this pilot study was to assess the effect of dextromethorphan/quinidine (DM/Q) in autistic adults (18-60 years of age). This was a randomized, blinded, crossover, study of 14 patients randomized to DM/Q or a placebo for 8 weeks, washed out for 4 weeks, then crossed over to the opposite treatment. There were no serious adverse events. Subjects were significantly lower on the Aberrant Behavioral Checklist for Irritability (ABC-IR) (F1,10 = 7.42; p = 0.021). Improvements in aggression and Clinical Global Impression were also seen. The findings suggest that DM/Q is well-tolerated and associated with improvements in irritability and aggression in adults with autism.