From Wikipedia, the free encyclopedia

Clinical data
Trade namesPatanol, Opatanol, Allelock, others
License data
  • AU: B1
Routes of
Eye drops, nasal spray
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • UK: POM (Prescription only)
  • US: ℞-only / OTC[1]
  • EU: Rx-only
Pharmacokinetic data
Elimination half-life3 hours
  • {(11Z)-11-[3-(dimethylamino)propylidene]-6,11-
    dihydrodibenzo[b,e]oxepin-2-yl}acetic acid
CAS Number
PubChem CID
CompTox Dashboard (EPA)
Chemical and physical data
Molar mass337.419 g·mol−1
3D model (JSmol)
  • O=C(O)Cc2ccc1OCc3c(C(\c1c2)=C\CCN(C)C)cccc3
  • InChI=1S/C21H23NO3/c1-22(2)11-5-8-18-17-7-4-3-6-16(17)14-25-20-10-9-15(12-19(18)20)13-21(23)24/h3-4,6-10,12H,5,11,13-14H2,1-2H3,(H,23,24)/b18-8- checkY
 ☒NcheckY (what is this?)  (verify)

Olopatadine, sold under the brand name Opatanol among others, is a medication used to decrease the symptoms of allergic conjunctivitis and allergic rhinitis (hay fever).[2] It is used as eye drops or as a nasal spray.[2] The eye drops generally result in an improvement within half an hour.[2]

Common side effects include headache, sore throat, eye discomfort, change in taste.[3][2] More significant side effects may include sleepiness.[2] It is unclear if use during pregnancy or breastfeeding is safe.[4] It is an antihistamine and mast cell stabilizer.[5][2]

Olopatadine was patented in 1986 and came into medical use in 1997.[6] It is available as a generic medication.[2] In 2020, it was the 268th most commonly prescribed medication in the United States, with more than 1 million prescriptions.[7][8]

Side effects[edit]

Some known side effects include headache (7% of occurrence), eye burning and/or stinging (5%), blurred vision, dry eyes, foreign body sensation, hyperemia, keratitis, eyelid edema, pruritus, asthenia, sore throat (pharyngitis), rhinitis, sinusitis, taste perversion, and vomiting.



Olopatadine synthesis:[9]



Olopatadine acts as a selective antagonist of the histamine H1 receptor, thus stabilizing mast cells and inhibiting histamine release.


Olopatadine was patented in 1986 by Kyowa Hakko Kogyo and came into medical use in 1997.[6]

In the United States, Pataday Twice Daily Relief was first approved by the FDA in 1996, under the name Patanol as a prescription drug and was indicated for the treatment of the signs and symptoms of allergic conjunctivitis (referring to ocular redness and itching due to allergies).[1] Pataday – now Pataday Once Daily Relief – was first approved by the FDA in 2004, as a prescription drug and was indicated for the treatment of ocular itching associated with allergic conjunctivitis.[1] These drugs are mast cell stabilizers, which work by preventing the release of histamine and therefore prevent or control allergic disorders.[1]

In February 2020, Pataday Twice Daily Relief and Pataday Once Daily Relief were switched to be over-the-counter drugs in the United States when the FDA granted the approvals of the nonprescription products to Alcon.[1]

Society and culture[edit]

Brand names[edit]

Brand names include Pazeo, Pataday, Patanol S, Patanol, Opatanol, Olopat, Patanase.[10] It is also available as an oral tablet in Japan under the tradename Allelock, manufactured by Kyowa Hakko Kogyo.[11]


  1. ^ a b c d e "FDA Approves Three Drugs for Nonprescription Use Through Rx-to-OTC Switch Process". U.S. Food and Drug Administration (FDA). 14 February 2020. Archived from the original on 15 February 2020. Retrieved 14 February 2020. Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ a b c d e f g "Olopatadine Hydrochloride Monograph for Professionals". Drugs.com. American Society of Health-System Pharmacists. Retrieved 26 March 2019.
  3. ^ British national formulary : BNF 76 (76 ed.). Pharmaceutical Press. 2018. p. 1126. ISBN 9780857113382.
  4. ^ "Olopatadine ophthalmic Use During Pregnancy". Drugs.com. Retrieved 26 March 2019.
  5. ^ Castillo M, Scott NW, Mustafa MZ, Mustafa MS, Azuara-Blanco A (June 2015). "Topical antihistamines and mast cell stabilisers for treating seasonal and perennial allergic conjunctivitis" (PDF). The Cochrane Database of Systematic Reviews. 6 (6): CD009566. doi:10.1002/14651858.CD009566.pub2. hdl:2164/6048. PMID 26028608.
  6. ^ a b Fischer J, Ganellin CR (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 549. ISBN 9783527607495.
  7. ^ "The Top 300 of 2020". ClinCalc. Retrieved 7 October 2022.
  8. ^ "Olopatadine - Drug Usage Statistics". ClinCalc. Retrieved 7 October 2022.
  9. ^ Ueno K, Kubo S, Tagawa H, Yoshioka T, Tsukada W (July 1976). "6,11-Dihydro-11-oxodibenz [b,e] oxepinacetic acids with potent antiinflammatory activity". Journal of Medicinal Chemistry. 19 (7): 941–6. doi:10.1021/jm00229a017. PMID 940112.
  10. ^ Drugs.com, Alcon's Patanase Nasal Spray Approved by FDA for Treatment of Nasal Allergy Symptoms
  11. ^ Kyowa Hakko Kogyo Co., Ltd. (2007). "Allelock Tablets 2.5 & Allelock Tablets 5 (English)" (PDF). Archived from the original (PDF) on 22 July 2011. Retrieved 10 August 2008.

External links[edit]