Dual action agents
The agents azelastine 0.05 per cent, epinastine 0.05 per cent, ketotifen 0.025 per cent and olopatadine 0.1 per cent combine the rapid symptom-relieving action of an anti-histamine with a longer-term mast cell stabilising effect. While systemic side-effects are rare, headache, burning and irritation of dual action drugs are reported as common. (2)
Many eye drops with names that include or imply a ‘dazzling’, ‘brightening’ ‘sparkling’ or ‘redness relieving’ effect (grouped under the title of ocular decongestants) contain agents such as naphazoline, which constrict conjunctival blood vessels, relieving hyperaemia, tearing and irritation. The effect is normally rapid, however, ocular side-effects such as mild pupil dilation and an increase in intraocular pressure may occur. Systemic side-effects have been reported. These side effects include changes in heart rate and blood pressure. (2)
Other simple, readily available methods of relieving symptoms of ocular allergy instead of, or as well as, medication include the following:
- To avoid contact with the source of the offending allergen be it a cat, grass/tree pollens, etc.
- Cool applications, which will have a vasoconstrictive effect and relieve itching.
- Dry eye drops which, if used several times per day, will have a flushing effect.
- Diluting and/or washing out allergens.
- Non-preservative inflammatory mediators.