Can Azarga (brinzolamide/timolol) eye drops cause urticaria?

Can Azarga Eye Drops Cause Urticaria?

Yes, Azarga (brinzolamide/timolol) eye drops can cause urticaria (hives) as a documented adverse reaction, though it occurs in less than 1% of patients according to clinical trial data. 1

Mechanism and Risk Factors

• Azarga contains brinzolamide, which is a sulfonamide derivative that can cause hypersensitivity reactions even when administered topically, as it is absorbed systemically 1
• Sulfonamide hypersensitivity reactions can range from mild urticaria to severe reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis in rare cases 1
• Sensitization to sulfonamides may recur when a sulfonamide is readministered regardless of the route of administration, including topical application 1
• Timolol, the beta-blocker component in Azarga, may also contribute to hypersensitivity reactions in some patients 2

Clinical Presentation of Urticaria

• Urticaria presents as short-lived itchy weals (hives) that can occur anywhere on the body with or without angioedema 3
• Individual weals typically last from 2 to 24 hours in ordinary urticaria 3
• Drug-induced urticaria can be part of the spectrum of allergic reactions that may include angioedema and, in severe cases, anaphylaxis 3

Management of Urticaria from Eye Drops

If urticaria develops after using Azarga eye drops:

• Discontinue the medication immediately if signs of serious reactions or hypersensitivity occur 1
• Consider alternative glaucoma medications that don't contain sulfonamides or beta-blockers 4
• For symptomatic relief of urticaria:
  • Non-sedating H1 antihistamines are the first-line treatment 3
  • Cooling antipruritic lotions such as calamine or 1% menthol in aqueous cream can provide symptomatic relief 3
  • In severe cases, oral corticosteroids may be needed for short-term use 3

Prevention and Precautions

• Patients with known sulfonamide hypersensitivity should avoid Azarga and other sulfonamide-containing eye drops 1
• A thorough medication history should be taken before prescribing any ophthalmic medication to identify previous drug allergies 5
• Patients should be informed about potential allergic reactions and advised to seek medical attention if they develop skin rashes, itching, or other signs of hypersensitivity 1

Alternative Treatment Options

• For patients who develop urticaria with Azarga, alternative glaucoma medications include:
  • Prostaglandin analogs (e.g., latanoprost, travoprost) 4
  • Alpha-2 adrenergic agonists (e.g., brimonidine) 4
  • Non-sulfonamide carbonic anhydrase inhibitors 4
  • Fixed combinations that don't contain sulfonamides 4

Important Considerations

• The risk of developing urticaria from Azarga appears to be low (reported at an incidence below 1% in clinical trials) 1
• However, patients with a history of sulfonamide allergy or previous drug-induced urticaria may be at higher risk 1
• The preservative benzalkonium chloride in Azarga may also contribute to ocular surface reactions in some patients 2

Remember that while urticaria is an uncommon side effect of Azarga, it is important to recognize it early and discontinue the medication if it occurs to prevent progression to more serious hypersensitivity reactions 1.