From the Guidelines
Levocetirizine is a second-generation antihistamine that commonly causes drowsiness, fatigue, and dry mouth as its most frequent side effects. Other potential side effects include headache, nausea, and mild dizziness 1. While less common, some patients may experience sore throat, cough, nose bleeds, or constipation. Serious side effects are rare but can include severe allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing), mood changes, and urinary retention.
Key Considerations
- Levocetirizine typically causes less sedation than older first-generation antihistamines like diphenhydramine, but patients should still exercise caution when driving or operating machinery until they know how the medication affects them 1.
- The elderly and those with kidney impairment may be more susceptible to side effects and often require lower doses.
- Levocetirizine works by blocking histamine receptors, preventing histamine from causing allergy symptoms, which explains why dry mouth and drowsiness occur as the medication affects histamine receptors throughout the body, not just those involved in allergic responses.
Comparison with Other Antihistamines
- Second-generation antihistamines like levocetirizine have a better safety profile compared to first-generation antihistamines, especially in children 1.
- Other second-generation antihistamines such as cetirizine, desloratadine, fexofenadine, and loratadine also have a good safety profile and are well-tolerated in young children 1.
Special Populations
- In children under 6 years, the use of OTC cough and cold medications, including antihistamines, should be avoided due to the potential toxicity and lack of efficacy 1.
- Second-generation antihistamines like levocetirizine are preferred over first-generation antihistamines in older adults due to their lower risk of sedation and anticholinergic effects 1.
From the FDA Drug Label
DO NOT USE • if you have kidney disease • if you have ever had an allergic reaction to this product or any of its ingredients or to an antihistamine containing cetirizine The potential side effects of levocetirizine are not directly listed in the provided drug label. However, it mentions that you should not use it if you have had an allergic reaction to this product or any of its ingredients, implying that an allergic reaction is a possible side effect.
- Kidney disease is a contraindication, but it is not explicitly stated as a side effect. The FDA drug label does not answer the question.
From the Research
Potential Side Effects of Levocetirizine
- The most common side effects of levocetirizine include somnolence, which is reported to be more frequent in patients taking levocetirizine compared to desloratadine 2.
- A study comparing the effectiveness of levocetirizine and desloratadine in patients with chronic urticaria found that increasing the dosage of levocetirizine up to 4-fold improved symptoms without compromising safety, and no serious or severe adverse effects were reported 3.
- Another study found that levocetirizine caused a marked inhibition of histamine-induced wheal and flare, with a duration of action of up to 28 hours, and was well-tolerated in healthy adult volunteers 4.
- The anti-inflammatory effects of levocetirizine may also contribute to its therapeutic benefits, although the clinical relevance of these effects is still being studied 5.
- A comparison of the risk of drowsiness and sedation between levocetirizine and desloratadine found that patients prescribed levocetirizine were more likely to experience drowsiness and sedation in the first month of observation, particularly those with allergic rhinitis without asthma/wheezing 2.
- A study on the effect of 5-days of levocetirizine treatment on histamine-induced skin reaction found that levocetirizine significantly reduced the skin reaction, with a maximum effect observed within the first 24 hours of treatment 6.
Comparison with Other Antihistamines
- Levocetirizine has been compared to other antihistamines, such as desloratadine, cetirizine, and fexofenadine, in terms of its efficacy and safety profile 3, 6, 2, 4.
- The results of these studies suggest that levocetirizine is a effective and well-tolerated treatment option for allergic rhinitis and chronic idiopathic urticaria, with a favorable safety profile compared to other antihistamines 3, 4.