alpha2-adrenoceptor agonists as nasal decongestants

Pulm Pharmacol Ther. 2007;20(2):149-56. doi: 10.1016/j.pupt.2006.03.012. Epub 2006 May 6.

Abstract

Nasal congestion, one of the major disease features of rhinitis, is induced by the filling of venous sinusoids causing mucosal engorgement with resultant obstruction of nasal airflow. The only available drugs that directly target the underlying vascular features driving nasal obstruction are the sympathomimetic alpha-adrenoceptor agonists due to their vasoconstrictor action. However, standard decongestants are nonselective alpha-adrenoceptor agonists, which have the potential for side-effects liabilities such as hypertension, stroke, insomnia and nervousness. In the present study, the effects of nonsubtype selective alpha(2)-adrenoceptor agonists BHT-920 and PGE-6201204 were evaluated in several isolated nasal mucosa contractile bioassays including dog, pig and monkey, and in a real-time tissue contractility assay using isolated pig nasal explants for BHT-920. The decongestant activity of PGE-6201204 was evaluated in vivo in a cat model of experimental congestion. Our results showed that alpha(2)-adrenoceptor agonists (1) contract nasal mucosa of different species, (2) exert a preferential vasoconstrictor effect on the capacitance vessels (veins and sinusoids), and (3) elicit decongestion. In conclusion, a selective alpha(2)-adrenoceptor agonist causing constriction preferentially in the large venous sinusoids and veins of nasal mucosa and producing nasal decongestion is expected to show efficacy in the treatment of nasal congestion without the characteristic arterio-constrictor action of the standard nonselective sympathomimetic decongestants.

MeSH terms

  • Adrenergic alpha-2 Receptor Agonists*
  • Adrenergic alpha-2 Receptor Antagonists
  • Adrenergic alpha-Agonists / administration & dosage
  • Adrenergic alpha-Agonists / pharmacology*
  • Adrenergic alpha-Antagonists / pharmacology
  • Animals
  • Azepines / pharmacology
  • Cats
  • Dogs
  • Dose-Response Relationship, Drug
  • Epinephrine / pharmacology
  • Female
  • In Vitro Techniques
  • Macaca fascicularis
  • Macaca mulatta
  • Male
  • Muscle Contraction / drug effects
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / physiology
  • Nasal Decongestants / administration & dosage
  • Nasal Decongestants / pharmacology*
  • Nasal Mucosa / blood supply
  • Nasal Mucosa / drug effects*
  • Nasal Mucosa / physiology
  • Prazosin / pharmacology
  • Swine
  • Swine, Miniature
  • Vasoconstriction / drug effects
  • Yohimbine / pharmacology
  • p-Methoxy-N-methylphenethylamine / pharmacology

Substances

  • Adrenergic alpha-2 Receptor Agonists
  • Adrenergic alpha-2 Receptor Antagonists
  • Adrenergic alpha-Agonists
  • Adrenergic alpha-Antagonists
  • Azepines
  • Nasal Decongestants
  • Yohimbine
  • p-Methoxy-N-methylphenethylamine
  • talipexole
  • Prazosin
  • Epinephrine