Pleconaril (Picovir[1]) is an antiviral drug that was being developed by Schering-Plough for prevention of asthma exacerbations and common cold symptoms in patients exposed to picornavirus respiratory infections.

[2] Pleconaril, administered either orally or intranasally, is active against viruses in the Picornaviridae family, including Enterovirus[3] and Rhinovirus.

[2] A pleconaril intranasal spray had reached phase II clinical trial for the treatment of the common cold symptoms and asthma complications.

[8] In Coxsackievirus, pleconaril efficiency correlates to the susceptibility of CVB3 with the amino acid at position 1092 in the hydrophobic pocket.

[6] The results of two randomized, double blind, placebo studies found Pleconaril treatment could benefit patients with colds due to picornaviruses.

[14] Participants in the studies were healthy adults from Canada and the United States, with self-diagnosed colds that had occurred within 24 hours of trial enrollment.

Pleconaril treatment showed a reduction in nose blowing, sleep disturbance, and less cold medication used.

[9] A Phase II study that used an intranasal formulation of pleconaril failed to show a statistically significant result for either of its two primary efficacy endpoints, percentage of participants with rhinovirus PCR-positive colds and percentage of participants with asthma exacerbations together with rhinovirus-positive PCR.

Methyl and bromine substitutions created an increase of pleconaril activity towards sensitive and resistant strains.

[14] In the clinical trial two women became pregnant due to the drug interfering with hormonal birth control by activation of cytochrome P-450 3A enzymes.