From the Guidelines
For elderly patients concerned about dry eyes, second-generation antihistamines like loratadine (Claritin) and fexofenadine (Allegra) generally have the best side effect profiles, as they are less likely to cause anticholinergic effects like dry eyes compared to first-generation antihistamines such as diphenhydramine (Benadryl) 1. These medications are preferred due to their selective H1-receptor antagonism with minimal anticholinergic activity, which means they block histamine receptors effectively while minimizing interference with tear production. Loratadine at 10mg once daily or fexofenadine at 60-180mg once daily would be reasonable choices. Cetirizine (Zyrtec) is another option but may cause slightly more dryness than loratadine or fexofenadine 1. Some key points to consider when prescribing antihistamines to elderly patients include:
- The potential for sedation and performance impairment, particularly with first-generation antihistamines 1
- The risk of anticholinergic effects, such as dry mouth and eyes, constipation, and urinary retention 1
- The importance of using preservative-free artificial tears to manage dry eyes, especially in patients already experiencing this condition 1
- The need to stay well-hydrated and avoid environmental irritants to minimize eye dryness while using these medications. It's also worth noting that oral antihistamines may induce or worsen dry eye syndrome, impair the tear film's protective barrier, and actually worsen allergic conjunctivitis, as stated in the conjunctivitis preferred practice pattern 1. Therefore, it's essential to weigh the benefits and risks of each medication and consider the individual patient's needs and medical history when making a decision. In general, second-generation antihistamines like loratadine and fexofenadine are good options for elderly patients concerned about dry eyes, due to their favorable side effect profiles and minimal anticholinergic activity 1.
From the Research
Antihistamines and Dry Eyes in the Elderly
- The available studies do not directly address the issue of dry eyes as a side effect of antihistamines in the elderly population.
- However, the studies suggest that second-generation antihistamines, such as loratadine, are generally well-tolerated and have a better side effect profile compared to first-generation antihistamines 2, 3.
- Loratadine is specifically mentioned as a safe and effective option for the treatment of allergic rhinitis in the elderly, with minimal sedation and anticholinergic effects 2, 4.
- Cetirizine is also mentioned as an effective option, but it may cause more sedation and dryness compared to loratadine 4, 5.
- It is worth noting that anticholinergic effects, which can contribute to dry eyes, are more commonly associated with first-generation antihistamines, and second-generation antihistamines like loratadine are less likely to cause these effects 2, 3.
Comparison of Antihistamines
- A study comparing loratadine and cetirizine found that both were effective in treating seasonal allergic rhinitis, but loratadine had a better tolerance profile, with less sedation 5.
- Another study found that loratadine and cetirizine were both effective in treating primary acquired cold urticaria, but loratadine had fewer adverse effects 4.
Considerations for the Elderly
- The elderly population may be more susceptible to the sedating and anticholinergic effects of antihistamines, making second-generation antihistamines like loratadine a better option 2, 3.
- The choice of antihistamine should be tailored to the individual's needs, taking into account concomitant medications and potential drug-drug interactions 3.