kết hợp loại thuốc thông mũi và thuốc thông mũi, thuốc kháng histamin có thể có một số trợ giúp trong điều kiện ứng dị ứng nhẹ. Nó là bình thường đối với những giọt sting. Trong một số trường hợp, một số loại có thể gây ra sự giãn nở đồng tử. | 48 Chapter 6 Table 6-2 Selected Decongestant Antihistamine Astringent Combinations Brand Names Clear Eyes ACR Naphcon-A Vasocon-A Visine-A Visine AC What the Patient Needs to Know__ Decongestant and decongestant-antihistamine combinations may be of some help in mild allergic conditions. It is normal for the drops to sting. In certain cases some types may cause pupil dilation. If you have dry eye avoid using decongestant drops. If symptoms persist see your eye doctor. Naphazoline oxymetazoline and tetrahydrozoline are close relatives and thus have about the same effect. Naphazoline is found in concentrations of and . Clinical studies have shown lower concentrations to be as effective as larger ones. Oxymetazoline and tetrahydrozoline are also available in a variety of over-the-counter OTC solutions. Ocular decongestants are relatively safe though they should be used cautiously in children and those with vascular disorders. The major ocular side effect is transient stinging. Phenylephrine and naphazoline can cause mild pupillary dilation in patients with compromised corneas. Both may also cause a slight increase in IOP as can tetrahydrozoline. Oxymetazoline does not seem to have this effect. The usual frequency for instilling these medications is 1 drop every 2 to 4 hours. Increasing the frequency is more effective than increasing the dosage. Patients must be warned that prolonged symptoms can signal more serious eye disease. Though these agents can be helpful in a few situations if symptoms persist patients should seek care from qualified eyecare professionals. OphT Antihistamines Oral Antihistamines Orally administered antihistamines can be beneficial for patients with moderate to severe allergic conjunctivitis rhinitis and sinusitis. There are many products available both OTC and by prescription. The most common OTC oral antihistamines are diphenhydramine ie Benadryl .
