Do you struggle with increased IC flares and bladder symptoms during allergy season? Antihistamines are listed as Step Two treatment options in the AUA guidelines for IC/BPS. Why?  Because the bladder wall contains the same kind of mast cells that also generate typical allergy symptoms.  Hydroxyzine HCL (Atarax) and hydroxyzine pamoate (Vistaril) have helped many IC patients over the years but there is another allergy and asthma medication that might help too.

Since 2001, montelukast (brand name Singulair) has shown decent enough promise that at this year’s American Urological Association meeting, Dr. Robert Evans suggested IC patients take montelukast during allergy season if they also have asthma. Montelukast is an oral anti-inflammatory that is used to treat allergies and prevent asthma attacks. Montelukast targets leukotrienes specifically. Leukotrienes are chemicals the body releases after coming into contact with an allergen or allergy trigger.(1)

Researchers suspect that leukotrienes play a role in IC. The first findings correlating IC treatment to montelukast were presented in November 2001 from researchers in Denmark.(2) The small study included 10 women who were diagnosed with IC based on the NIDDK definition of IC. The woman all also had to have mast cells in their muscle tissue. The women took montelukast daily for three months. After one month of treatment, all of the women showed a statistically significant reduction in urinary frequency, nocturia and pain. By the end of the three months, the results remained just as positive. The women went from an average of voiding 17.4 times a day down to 12. Nocturia went from an average of 4.5 down to 2.8. Pain decreased from 46.8 to 19.6 on a visual analog scale. None of the women suffered from side effects. The researchers felt the findings were significant and further studies were needed.

In 2007, researchers from Pennsylvania State University found that montelukast also showed promise as a treatment for vulvar vestibulitis, which is vulvodynia specifically in the vulvar region.(3) It is a condition that is often found in IC patients and is usually described as burning or cutting type pain in the vulvar region. The researchers compared 29 vulvar vestibulitis patients treated with montelukast to 18 vulvar vestibulitis patients not taking montelukast. Over 2.5 years, the patients who took montelukast had a 52 percent improvement in symptoms as opposed to 15 percent in the patients who weren’t taking montelukast.

Four years later, a group of researchers from the School of Pharmacy and Health Professions at Creighton University in Nebraska released findings about montelukast and IC.(4) The researchers followed a 64-year-old male who had a history of IC. His previous treatments had not been very beneficial. When he was prescribed montelukast for seasonal allergies, though, he also experienced a great improvement in urgency and pain. His urinary symptoms returned when he stopped taking the montelukast, prompting the researchers to conclude the montelukast was the cause of his improved IC symptoms. They also felt like montelukast seemed a promising treatment for IC but further research was necessary.

That leads to June of 2018 when a group of researchers from the United States, Pakistan and India came together and released a case report and review of literature about the benefit of montelukast in treating IC patients.(5) They followed a 28-year-old female patient who was diagnosed with IC. While in the hospital for IC symptoms, the patient had two asthma attacks and was given an inhaler as well as montelukast. While the medication helped her shortness of breath and asthma symptoms, the patient also noticed the next day that her urinary symptoms were better. She continued to take montelukast after being released from the hospital and two months later reported that her symptoms were substantially reduced and her suprapubic pain, which had been intense before, was gone. The researchers believe that montelukast worked for her IC symptoms in great part because montelukast inhibits leukotriene receptors in the bladder, which prevents mast cells being activated.

While more research is needed for treating IC symptoms with montelukast, patients who are already taking a medication for asthma or seasonal allergies can at least bring it up with their doctor and decide the best plan of action.


  1. WebMD. Leukotriene Modifiers and Allergies.
  2. Bouchelouche K, et. al. The Cysteinyl Leukotriene D4 Receptor Antagonist Montelukast for the Treatment of Interstitial Cystitis. J of Urol Nov. 2001, Volume 166, No. 5.
  3. Kamdar N, et. al. Improvement in vulvar vestibulitis with montelukast. J Reprod Med Oct. 2007, Volume 52, No. 10.
  4. Traut JL, et. al. Montelukast for symptom control of interstitial cystitis. Ann Pharmacother Sept. 2011, Volume 45, No. 9.
  5. Ullah MW, et. al. Painful Bladder Syndrome/Interstitial Cystitis Successful Treatment with Montelukast: A Case Report and Literature Review. Cureus June 2018, Volume 10, No. 6.