Thursday, 8 January 2009

Ophthalmic Topical Astringent Eyedrops, Decongestants + Antihistamines


Topical decongestants and antihistamines are needed when the px's ocular irritation/discomfort is a chemical irritant, an allergen or both. Oral antihistamines are used too.


Astringents are meant to have some sort of cleansing action beyond that of saline. Borate eye washes were astringent and used to be the main treatment for anything. They are revived in the form of these eyedrops and known as 'natural' cleansers/moisturisers. They are normally indicated for prn use for any form of MILD eye irritation/discomfort which proves to be responsive.
  • P Optrex Eye Drops 10ml bottle w/witch hazel
  • SL Optrex refreshing eye drops 10ml bottle w/witch hazel and glycerin
  • P Zinc Sulphate 0.25% Eye Drops 15ml bottle

These have no medical definition and are generally used by people who have slightly irritated/tired eyes w/hyperaemia that is unacceptable cosmetically. They contain small amounts of both astringents and decongestants and the products have similar warnings to those prods w/higher concentrations. They also contain natural/plant type stuff.
  • SL Vital Eyes Brightener 10ml bottle w/flower petal extracts, small amount of witch hazel, trace amounts of zinc sulphate 0.02% and naphazoline 0.005%
  • SL Optrex Fresh Eyes Brightener 8ml w/witch hazel, borate buffer, naphazoline 0.01% and BkCl. Similar drops can contain plant extracts, glycerine and EDTA

Usually P Medicines. The decongestant activity is a result of direct alpha adrenergic action or direct histamine H1 blocking action - either attenuating vasodilation or even causing vasoconstriction. It's suggested that some alpha 2 receptors are also affected by the drug and that would relieve signs/symptoms such as discomfort, puffiness, chemosis and reflex lacrimation. If Anti-H is also included then expect efficacy against itchiness symptoms too. All the products contain BkCl and EDTA usually as preservative
  • All products are meant to provide occasional relief of symptoms associated w/mildly irritated eyes and also improve the cosmetic appearance of the external eye, used eg 2-3 times daily. They aren't for use to whiten eyes that just need a wash. q2hr = excessive use
  • Cause of irritation should be identified. If there's a genuine allergic component then use something w/anti-h. For dirt and dust an eyewash might have better results.
  • They don't work as prophylactic agents. They have a slight affect but that's probs due to reflex tearing providing a mini 'eye wash'.
  • Excessive use can cause rebound effects and an induced red eye. This is due to a mild toxic reaction or type IV allergic reaction due to prior sensitization to any of the ingredients of the eyedrops.
Guidelines for use
  • Contrainds: Narrow angle glaucoma - adverse effect is angle closure
  • Warnings for systemic diseases - shouldn't be recommended to anyone with HBP, Heart Probs, Stroke, Hyperthyroidism. Any sympathomimetic drug could increase BP. These prods don't contain high concs of the drugs but they are frequently overused and could produce systemic effects.
  • Interactions - carefully supervise use if px taking MAO inhibitors/anti-depressants
  • Not for use w/eye infections, will just relieve symptoms and do nowt else. Even mask them
Current drops available
  • Naphazoline 0.01% alph-adrenergic eg P Murine. Also w/witch hazel 12% eg P Eye Dew Clear. All preserved w/BkCl. Also w/blue dye for cosmesis in Dazzling Eye Drops
  • Xylometazoline 0.05% as a-1 and a-2 adrenergic in combo w/antazoline 0.5% as histamine H-1 blocker. Preserved w/BkCl and EDTA eg P Otrivine-Antistin
Topical Anti-H drops on their own are additional supply only.

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