Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
0.5 mg/mL as nasal spray and eye drops
Indication: allergic rhinitis/conjunctivitis
Levocabastine is a H1 receptor antagonist. It has a rapid onset of action and the antihistamine effect lasts for several hours.
In patients with seasonal allergic rhinitis, the nasal spray is more effective than placebo, but less effective than beclomethasone for the relief of symptoms. Levocabastine and sodium cromoglycate are of similar efficacy. Although similar trends may apply in cases of perennial allergic rhinitis, there is less supporting evidence.
The eye drop formulation is more effective than placebo in relieving the symptoms of seasonal allergic conjunctivitis. Levocabastine eye drops instilled twice a day are also as effective as sodium cromoglycate given 4 times a day.
Most adverse effects are due to local irritation of the eye or nose. However, up to 60% of the ocular dose and up to 80% of the nasal dose are absorbed. This absorption creates the potential for systemic adverse effects and patients should be informed of the possible risk of sedation.
While some patients may prefer levocabastine to oral antihistamines, safety and efficacy have not been established beyond one month of therapy. Therefore, levocabastine has only been approved for short-term use.