Quieting Allergic Eyes With Oral Antihistamines
BY WILLIAM TOWNSEND, OD
Allergic responses are dependent on the numerous chemical mediators released by mast cells as they degranulate. Histamine is the best-known mediator. Many anti-allergy medications block the release or action of mediators by competing at their activity sites.
The introduction of several excellent topical anti-allergy ophthalmic drops has largely eliminated the need for oral medications in treating allergic, vernal and atopic eye disease. In some instances, it is necessary to prescribe oral antihistamines to quiet the eyes and reduce symptoms.
Oral Antihistamine Options
Older generation antihistamines such as Benedryl (diphenhydramine, Parke Davis), Dramamine (dimenhydrinate, Pharmacia Upjohn) and Chlor-Trimeton (chlorpheniramine maleate, Schering) are effective but have anticholinergic and sedative side effects. Recently-introduced products cause fewer side effects, but are not currently available over-the-counter. They are considerably more expensive than their OTC complements.
For patients with severe allergic eye disease, try adding an oral antihistamine to your treatment regimen. Chlor-Trimeton is an excellent choice if anticholinergic effects are not an issue. Dosing in the evening allows the anticholinergic and sedative effects to wear off during sleep.
Allegra (fexofenadine HCl, Aventis) is available as a 60mg tablet. This medication has good clinical activity, and it has few sedative or anticholinergic effects. Allegra is prescribed bid and has a good safety record.
Claritin 10mg (loratadine, Schering) is a popular choice because of its once-daily dosing and reduced anticholinergic effects. Many patients find that it is not very efficacious. For patients who are sensitive to anticholinergic effects, this may be the drug of choice. In instances where Claritin alone is not effective, consider Claritin D. The addition of pseudo-ephedrine sulfate to loratadine gives patients more relief from seasonal allergies.
Zyrtec (cetirizine, Pfizer) is available in 5mg or 10mg tablets. Zyrtec has reduced sedative effects and once-daily dosing. It is currently our favorite medication in treating patients with seasonal allergic conjunctivitis and other allergic syndromes.
Dr. Townsend is in private practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center. E-mail him at firstname.lastname@example.org.
A Fond Farewell
In October 1993, I published my first article in Contact Lens Spectrum. The article, "Five Qualities of a Treatment Giant," outlined those qualities that distinguish run-of-the-mill practitioners from outstanding clinicians. I sincerely hope that the information I have presented has helped you, the readers, deal with and treat your patients. After eight years, I have run out of ideas, and it is time to rest for a while. But in ending my time with CLS, I must express my appreciation to several people.
There are many people I would like to thank for making my eight-year sojourn at CLS possible and successful. First, I would like to thank Dr. Jan Bergmanson at University of Houston for suggesting to the management of this publication that I would be a suitable candidate for the position. He has made a number of contributions to optometry, publishing dozens of important articles that are clinically applicable for those of us in the trenches. I would like to thank Dr. Joe Barr, who has been my editor for the entire time. He has allowed me to have free reign to write and publish articles that were occasionally controversial or cutting edge. I would like to thank all the other editors, and there were many, that contributed to my understanding of writing and producing solid, usable information in journal form. I owe a great debt of gratitude to Dr. Janet Townsend and Dr. Kevin Apple, who shared many of the cases cited in my articles with me. Without their help and support, many of my most interesting columns would have not been written. Finally, I want to thank you for reading the articles and responding in such a positive way.