Wednesday, July 4, 2012

TOPICAL DECONGESTANTS

Pharmacological treatments


How do they work?


By producing vasoconstriction in the nasal sinusoids, which are regulated by adrenergic-type mechanisms, specifically by α-receptors. Three (3) types may be identified:

  • α1 (post-synaptics): particularly sensitive to the release of noradrenalin by the sympathetic nerve fibres. Phenylephrine and Methoxamine are α1-adrenergic receptor agonists. Phenylephrine is very seldom used because it may cause hypertension and reflex bradycardia.
  • α2 (pre-synaptics): responsible for inhibitory retrocontrol of noradrenalin release. α2-adrenergic receptor agonists like methoxamine have a more powerful, longer lasting and selective effect.
  • α2 (post-synaptics): sensitive to the adrenaline produced by the adrenal medulla of the suprarenal capsules. The agonists of these receptors are derived from clonidine, such as Oxymetazoline, Xylometazoline, and Naphazoline, have a slow but prolonged onset of action and are the most frequently used.

  • What should be recommended for their proper use?
    • Clean the nose before every application.
    • Administer with the head upright, breathing in deeply.
    • Do not use for more than 3-5 days to avoid the rebound effect.
    What situations may give rise to problems related to these medicinal products?
    • There may be a worsening in the conditions of diabetic and hypertensive patients with glaucoma, heart diseases and hyperthyroidism.
    • Warn the patient about driving and the use of machinery since these drugs may cause drowsiness.
    Do these drugs interact with other medicinal products?
    • No interactions have been described for Naphazoline, Oxymetazoline, Xylometazoline or Tramazoline.

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