Singulair and Irritability: What Users Say

• Ang...
• March 9, 2020

For Asthma "Be careful! After years of being misdiagnosed, I was given Singulair. Within 4 weeks, I no longer needed my nebulizer or rescue inhalers. I gradually became more tired and extremely agitated. I began hearing voices in my own home, and I live alone. It got worse, not better. One night, I was convinced someone was in my home. Every light in the house was on. I still kept seeing someone! Coming from a military background and secure in owning firearms, I was searching my home with a gun. I was looking for an intruder who was NOT there! That was my final straw. I threw my Singulair in the garbage. I’m still agitated and frustrated. I am going to try over-the-counter medication deemed safe. I’m not sure how long the agitation and tiredness will last. I pray this will help someone. Please be careful on this medicine. For me, it’s not worth it. In 55 years, I’ve never seen anyone or heard voices in my home until Singulair. (5 weeks total taking it)"

• San...
• Taken for 1 to 6 months
• April 19, 2020

For Allergic Rhinitis "I was given this medication, Singulair, for chronic nasal congestion and rhinitis. After about 2 months, I started to notice my mood changing. I was more argumentative, almost to the point of aggression. When I started to have bizarre dreams, I then researched the side effects of this drug. Here is what was listed: mental/mood changes (such as agitation, aggression, anxiety, trouble sleeping, abnormal dreams, sleep-walking, memory/attention problems, depression, hallucinations, thoughts of harming yourself/suicide). I immediately stopped taking this medication (it wasn't helping that much anyway) and these side effects have stopped completely. PLEASE be mindful of ALL the side effects of any medications you are taking! I never would have believed that something to help with nasal congestion could cause such problems."

• Mad...
• Taken for 2 to 5 years
• November 2, 2020

For Asthma "While on this medication, my asthma and allergies were almost non-existent. However, I also developed severe depression that almost took my life, anxiety, became easily agitated, and had pain in my mouth and back. Since I stopped, I feel happier, more patient, less sore, but my allergies have come back. If it weren't for the side effects, I would have kept taking it."

• Kdu...
• Taken for less than 1 month
• March 31, 2015

For Asthma "Started Singulair approximately 1 week ago. I will say it's an asthma miracle, but the side effects are unreal. I had extreme irritability (out of character for me), severe fatigue when normally active, mood changes, depression, anxiety. I wish doctors would really explain this to new users. Thanks to all of you who reviewed this medicine and gave me insight on what was going on, that's the reason for my post too."

• Sco...
• Taken for less than 1 month
• June 14, 2018

For Allergic Rhinitis "This drug is not for everyone. I took it for just three days and got very depressed, even to the point of having really dark thoughts, had a constant headache, an upset stomach, deep soreness in my teeth, mood swings, and irritability. However, it did help my allergies. Be very conscious of how you feel when you try this drug."

• MM ...
• Taken for 5 to 10 years
• October 10, 2018

For Allergic Rhinitis "I am a parent of two children. Both children took Singulair for allergies. Both children had issues while taking Singulair and experienced withdrawal effects once I stopped the medication. My daughter developed tics, tremors, anger, rage, OCD, anxiety, mood swings, and agitation, to name a few side effects. My son developed frequent urination, muscle issues, joint pain, and sadness. Both my children developed a hypersensitivity to all artificial sweeteners, dyes, and all emulsifiers/preservatives as the inactive ingredients are made up of most of these items. Their hypersensitivity to artificial sweeteners, dyes, and emulsifiers/preservatives still continues even though they stopped the medicine."

• Ver...
• November 5, 2016

For Asthma "Since taking Singulair I have tooth pain, tingling in my face, and a bad metallic taste in my mouth. Plus my anxiety level went up, feel really tired, and very agitated. Stopped taking it last night. Hope these side effects go away soon. This metallic taste is driving me crazy! This is the 2nd time I've tried it. Same side effects and more."

• Cyn...
• Taken for less than 1 month
• August 28, 2022

For Allergic Rhinitis "My dr warned me Singulair had a black box warning due to sometimes causing depression and suicidal symptoms, but I wasn’t concerned. I am a psychotherapist and don’t usually have side effects to meds. Shortly after taking Singulair, I began to feel agitated and depressed. I felt negative and paranoid. Then one day I thought, “What is the point of living?” I remembered my dr mentioning the black box warning and stopped taking Singulair. My mood improved dramatically each day I was off Singulair. Please be careful."

• Sti...
• Taken for less than 1 month
• April 23, 2016

For Allergic Rhinitis "I tried Singulair because I have nasal allergies that turn into nasty sinus infections every couple of months. I also have panic disorder, but it's well controlled with medication. I was only able to take Singulair for 4 days due to side effects, so I can't say how well it works. It made me so sleepy that I was sleeping 12-15 hours a day and still tired when I was awake. I haven't had a panic attack in over a year, and my anxiety went through the roof on this stuff. My panic attacks were so bad that I was having trouble driving. I was also moody and irritable the days I took it. Luckily, all of the negative side effects went away within a couple of days of stopping Singulair. Stay away from this drug if you are prone to anxiety!!!"

• Gco...
• October 19, 2016

For Allergic Rhinitis "My wife was on this stuff for at least a couple of years. She suffered severe tiredness, nightmares, irritability, and even suicidal thoughts, accompanied by severe depression! Although it did make her feel better, the side effects are not worth it at all! She switched to Flonase, and it is just as good. Please, if you are on this medicine and have any of these side effects, please stop!"

• Nor...
• March 27, 2016

For Asthma, Maintenance "I have mild asthma that occasionally worsens to be more moderate. I'm another person who has mood effects from taking Singulair, and in addition, it's affecting my ability to enjoy certain flavors. It feels like an antihistamine, sort of, causing my mouth to feel dry, and I feel thirsty a lot. I'd live with that, but I am experiencing this weird agitation that's quite uncomfortable. I'm very aware of it, and I'm an adult, not a kid, so I probably won't bite anybody's head off. However, I think it might not be worth it to me, and I think I'll stop it for a few days to compare how I feel then with what I'm feeling now."

• Anonymous
• January 6, 2012

For Allergic Rhinitis "Yes, I think this medicine works in treating allergic rhinitis, but after not being able to sleep at all the night I took it and being extremely agitated with mood swings tapering off into the next day after a full night's sleep, I will take it no more. I think each person needs to weigh the benefits versus the side effects for them. Everyone is, of course, different and each responds in their own way to all of these medicines. Just monitor your reaction to the drug closely if you do decide to use it and make the right decision for you to continue it or not."

• Anonymous
• May 17, 2011

For Allergic Rhinitis "I had constant sinus infections caused by allergies. Tried several medications, but nothing would work. Doctor finally prescribed Singulair, and I have had relief ever since. The only problem is the medicine can make me very irritable to the point that my wife cannot stand me, and sometimes Singulair can cause insomnia."

• Mom...
• October 13, 2010

For Asthma "My son has had asthma from the beginning, he was placed on Singulair at 18 months. It did seem to help, but he has now developed side effects, and we have taken him off of it. He becomes very agitated and aggressive. He is normally a very calm and sweet child. It took a while to put two and two together. We took him off, and his sweet nature came back. Truthfully, it scared me how much this medicine affected his mood. It works great for asthma, but we won't use it anymore."

• Hid...
• Taken for 1 to 2 years
• May 26, 2023

For Asthma "I was on this for a year with no improvement in my asthma. Two days after getting off of it, I began to have horrific withdrawals, including severe headaches, exhaustion, irritability, weepiness, depression, lightning shocks throughout my body, severe body aches, and inability to sleep. The worst seems to have occurred for 48 hours straight, with no signs of fever or sore throat to indicate flu. After seeing others in forums, it seems to be this medication."

• Rev...
• Taken for 6 months to 1 year
• May 2, 2016

For Allergic Rhinitis "Singulair causes symptoms in children that look like ADHD or ADD. It causes irritability, aggression, impulsivity, and hyperactivity in children. Before you treat your child for ADHD, try switching to an allergy or asthma medicine that isn't this or a corticosteroid."

• Jen...
• Taken for less than 1 month
• October 25, 2021

For Allergic Rhinitis "I started using Singulair about 11 days ago, and I have noticed a big difference with my severe allergies. Unfortunately, I have also developed constipation, which is not listed as a side effect, and irritability. Both have gotten so bad I discontinued use last night, and after 12 hours, I am 75% better with both constipation and irritability, but oh, my allergies are back. Sigh."

• Anonymous
• April 27, 2009

For Allergic Rhinitis "Tried it and it worked great except for the side effects of depression, anxiety, agitation, depression."

• pre...
• Taken for less than 1 month
• January 21, 2013

For Asthma "Very good for asthma and allergies, but my mood changed for the worse. I woke up angry for no reason and very irritable. Made my anxiety worse too. I stopped it."