Azélastine

Azelastine, sold under the brand name Optivar among others, is a H1 receptor-blocking medication primarily used as a nasal spray to treat allergic rhinitis (hay fever) and as eye drops for allergic conjunctivitis. Other uses may include asthma and skin rashes for which it is taken by mouth. Onset of effects is within minutes when used in the eyes and within an hour when used in the nose. Effects last for up to 12 hours. Common side effects include headache, sleepiness, change in taste, and sore throat. It is unclear if use is safe during pregnancy or breastfeeding. It is a second-generation antihistamine and works by blocking the release of a number of inflammatory mediators including histamine. Azelastine was patented in 1971 and came into medical use in 1986. It is available as a generic medication in the United States. In 2020, it was the 173rd most commonly prescribed medication in the United States, with more than 3 million prescriptions. Azelastine nasal spray is indicated for the local treatment of the symptoms of seasonal allergic rhinitis and perennial allergic rhinitis, such as rhinorrhea, sneezing and nasal pruritus in people five years of age and older. In some countries, it is also indicated for the treatment of vasomotor rhinitis in adults and children ≥ 12 years old. Azelastine eye drops are indicated for the local treatment of seasonal and perennial allergic conjunctivitis. Azelastine is safe and well tolerated in both adults and children with allergic rhinitis. Bitter taste, headache, nasal burning and somnolence are the most frequently reported adverse events. US prescribing recommendations warn against the concurrent use of alcohol and/or other central nervous system depressants, but to date there have been no studies to assess the effects of azelastine nasal spray on the CNS in humans. More recent studies have shown similar degrees of somnolence (approx. 2%) compared with placebo treatment. The most common side effect is a bitter taste (about 20% of people).