Bactrim and Allergic Reaction: What Users Say

• Van...
• Taken for less than 1 month
• September 12, 2018

For Bacterial Infection "There seems to be a lot of people who have had side effects. But seriously, Bactrim is a drug with not many side effects for most people. The people who mainly think to write comments are usually the few that have had the bad reactions. For me, it was fine."

• Man...
• Taken for less than 1 month
• December 12, 2019

For Bacterial Infection "This drug was almost the end of me. I had taken it several times before with no issues. However, this time I took three pills and ended up in the hospital with Stevens-Johnson syndrome, which is a serious severe reaction. It started with blisters covering the inside of my mouth. And then it spread all over my face and chest. I felt like I was literally ON FIRE!!! After very large doses of steroids and antihistamines, we were able to save my face. No scarring, thank God. But 2 months later, and I’m still struggling with the feeling of my face and chest getting really hot."

• Wis...
• Taken for less than 1 month
• June 2, 2022

For Bacterial Skin Infection "I have severe medical anxiety thanks to terrible reactions to medications that started after a surgery. I’ve been on too many that made me feel absolutely crazy and had terrible side effects. I made the mistake of reading these reviews before starting Bactrim and was absolutely terrified. I took the first pill and immediately knew I was going to die and had terrible anxiety about this reaction I was going to have. But, guess what? I was fine! I just took my last dose of a 7-day course, and the only issue I had was making the mistake of going in the sun. I ended up burning a lot quicker than normal (there’s a warning for that). In fact, it had a pro to it… turns out it also helped my never-ending stomach issues. Don’t let the other reviews scare you. As someone else said, most people only take the time to write reviews after a negative experience. That’s why I decided to start reviewing my positive ones."

• Anonymous
• September 2, 2009

For Bronchitis "I had a bad case of bronchitis, and Bactrim was prescribed. Within a day, I was feeling better and was completely well in 3-4 days. Amazing! However, my wife was prescribed the same drug for her bout of bronchitis and found that she was allergic to it and had horrible stomach pain. So it's obviously not for everyone."

• Aes...
• October 16, 2015

For Acne "I am 20 years old and have been taking Bactrim since I was 14. Originally, I started with a twice-daily dose but have since decreased to half a pill every other day. It is not a perfect fix, as I still have to be attentive and wash my face twice a day and occasionally use an acne cream, but otherwise, it works quite well. Before starting Bactrim, I had moderate but painful acne, and I now only get small, infrequent pimples. I am now a pharmacy student and thought I should warn people that extended use of any drug is dangerous. Also, Bactrim is NOT an antibiotic but is a synthetic sulfa drug, meaning it is made from chemicals. Some people are severely allergic to sulfa drugs and should be cautious and talk to their doctor before taking this drug."

• bre...
• Taken for less than 1 month
• June 13, 2023

For Urinary Tract Infection "Bactrim is a very good antibiotic in my experience. At first, I was so scared to take it because of all these negative reviews. My UTI was antibiotic resistant, and Bactrim cleared it up within 3 days. Don’t let these reviews scare you. The people who have bad reactions usually don’t follow the instructions: stay out of the sun, drink tons of water, eat a full meal before taking your dose! :)"

• mae...
• October 30, 2019

For Urinary Tract Infection "I broke out with a rash just after day 10 of Bactrim, it was sudden and scared the heck out of me! I had a million red spots covered from head to toe (neck, stomach, back, and legs were the worst). I went into the clinic and they told me to stop taking it right away. So apparently, I am one of those 3% with a sulfa allergy. The funny thing is the nurse told me she also has an allergy to it. I then told a coworker about it, and she also had an allergy. With my follow-up appointment, I asked about the small percentage of patients affected-she told me it is rising and is much higher than it used to be (related it to the kind of rise we're seeing in gluten allergies). No reason! So if you get a rash, stop taking it! Day 1 rash recovery-slightly better, fewer red spots on ankles and feet. Day 2-much improved, fewer on shoulders/neck, and lower legs were cleared. Day 3-thighs are starting to clear as well as back/stomach. My temperature never went up during this process."

• Anonymous
• April 28, 2011

For Bacterial Infection "Pain and swelling in the vicinity of my tailbone led to an emergency room visit where I had a pilonidal cyst drained. After the doctor incised and drained my cyst, he prescribed me Bactrim and Keflex. He explained that the Keflex was intended to treat the infection if it was MRSA while Bactrim would cover all other bases. A week into my 10-day course of antibiotics, I went to bed with a developing fever. In the morning, I awoke to discover that my entire body was covered in a red, splotchy rash. I immediately went to a medical professional who informed me that I was likely having a severe allergic reaction to Bactrim. I was informed that my fever and rash would persist for days to weeks and may progress to anaphylaxis."

• Anonymous
• Taken for less than 1 month
• September 6, 2019

For Bacterial Skin Infection "This has been my first go-to antibiotic. I am allergic to so many. Yes, it’s an older antibiotic and I have to take it longer than most. I know my symptoms for allergic reactions, but I do know what works best for me."

• Anonymous
• July 3, 2010

For Urinary Tract Infection "Please make sure you are not allergic to this drug. I had no idea I was and ended up with horrible allergic reactions. Shortness of breath, heavy chest, rapid pulse - it was at 120 beats per minute for 2 days straight, now it comes and goes. It has been 4 days, and I am not better. I really have felt like an anxiety or panic attack is happening all the time."

• DSa...
• Taken for less than 1 month
• August 18, 2017

For Bacterial Skin Infection "I had an incredibly bad reaction to Bactrim that led to multiple organ dysfunction/failure. I ended up in ICU for several days with liver and kidney failure that progressed into pulmonary edema/ARDS. I came very close to dying after my kidneys shut down and my lungs filled with fluid. I have now been advised to never take another sulfa-based drug."

• Sad...
• Taken for less than 1 month
• March 20, 2019

For Bacterial Skin Infection "It's 1 in the morning, and I am still having breathing problems after being rushed to the hospital due to an allergy to Bactrim. They gave me an EpiPen, it's been 2 hours, and I am still having trouble breathing. I'm very young and healthy, and something like this never happened to me before. I'm very scared and worried that taking this medicine has given me even worse problems. Has anyone else had this experience?"

• Anonymous
• January 25, 2010

For Acne "I have horrible hormonal acne, and Bactrim has been the only systemic drug that has helped. Problem is, I took it for years, randomly when needed. After years of usage, oddly, I became allergic to it. I broke out in large red spots that were extremely sensitive. It's a serious allergy. I have permanent dark bruises all over my body, and it has been years since I've used it. If you haven't tried Bactrim, try it. It will work for you."

• Idk...
• February 22, 2017

For Acne "Okay, so I had suffered with acne ever since I hit puberty. I was a 'pizza' face, so to say. I had tried multiple things and thousands of dollars to try and get rid of my acne. Eventually, though, I found out I had PCOS, so yay! Hormonal acne. Anywaays, my dermatologist prescribed me Bactrim along with spironolactone. Within a week, I had a completely clear face. No acne at all. But unfortunately, after 3-4 weeks, I found out I was a part of the unlucky few who ended up being allergic to it. So sad. If I could ever take it again, I would in a heartbeat. But it has been about 6 months since I've been on Bactrim, and I am still pretty much clear with very few breakouts."

• Anonymous
• December 16, 2011

For Urinary Tract Infection "I used this medication a few times to treat a urinary tract infection, and two times I experienced severe allergic reactions where I had hives on my tongue, neck, and face, and they left scars. Be careful."

• Anonymous
• February 8, 2011

For Prevention of Bladder infection "I started taking Bactrim on a Tuesday. By Wednesday, I was depressed and had terrible knots in my stomach. I was going to the bathroom almost every hour and had hives all day and night. Thursday, I felt a lot better, and my symptoms were mostly relieved as well. I thought it was worth the hives and frequent bathroom breaks. On Friday, my lips, gums, tongue, and face were all swollen. I didn't think it was the medication at all. The doc's nurse called to tell me that my culture came back and that they were switching my medicine. When I changed the medicine on Saturday, I had sores in my mouth along with the swollen gums. I made a dental appointment thinking that it was due to an immunization problem. By Sunday, I called my doctor and learned that I developed allergies."

• Gwe...
• February 20, 2015

For Acne "The medicine worked so well on my acne. Not even 10 days after beginning the prescription, and my acne was already clearing up. Unfortunately, I had an allergic reaction to the sulfa in the medicine and was rushed to the hospital because the reaction caused the platelet levels in my blood to drop to extremely dangerous levels. I'm still searching for a medicine that works like this one did without the sulfa in it."

• Che...
• Taken for less than 1 month
• December 12, 2020

For Bacterial Skin Infection "I had a large abscess on my abdomen and was first put on Keflex. After a few days, the infection was spreading and I now had diarrhea. The clinic doctor switched me to Bactrim. I was nervous after reading reviews, but by the next day, I saw major improvement. I finished my full course and I feel great. It didn’t even upset my stomach. Obviously, some people have allergic reactions to it, but for me, it worked wonderfully."

• Anonymous
• August 6, 2015

For Urinary Tract Infection "I took this medicine for 3 days and experienced severe nausea. Been off of it for 1 and I'm still experiencing it off and on. It feels horrible. I will never take this medicine again. I must be allergic to it."

• Ano...
• Taken for less than 1 month
• April 17, 2015

For Acne "While I was only on Bactrim for one week, I feel like it was an experience to share! In this week, I did notice a difference in my skin, and it was probably the best my face has ever looked. That being said, I developed allergy symptoms pretty quickly but did not make the connection right away. High fever and nausea for a few days before a full-body rash on the 8th day. I was taking two pills a day. Always watch for symptoms and consult the doctor. I would still recommend this medication to others as it appeared VERY promising at clearing up my moderate hormonal acne. If I could go on it again, I would."

• Cat...
• Taken for less than 1 month
• January 25, 2020

For Acne "I took Bactrim for my cystic acne for the first time a few days ago. Took my first dose a few hours before bed and started to notice my tongue and mouth going numb. I took 2 Benadryl to soothe the symptoms. The next morning, I called both my pharmacist and doctor, and they told me that it was definitely an allergic reaction. Fast forward a few days later, my mouth has the same symptoms as if I burned my mouth on something scalding hot! My tongue has an entire layer 'burned' off, as well as my inner left cheek, with blisters inside my mouth. Needless to say, I’m definitely allergic to this medication. They then prescribed me minocycline, but I’m very afraid to even attempt to try it after this experience!"

• Lis...
• September 26, 2020

For Bacterial Infection "I had a lump removed from my breast. It ended up getting infected from the inside. So I was prescribed Bactrim. It was about a week and a half before I noticed I was developing a rash. I went through my whole house, cleaning and racking my brain, trying to figure out why I was having an allergic reaction. I didn't even think of having an allergic reaction to the medicine. So I called my doctor, and they took me off it ASAP. It didn't help my infection, and it made me break out everywhere, and I mean everywhere, lol!"

• Lol...
• Taken for less than 1 month
• March 29, 2022

For Urinary Tract Infection "I was prescribed Bactrim after two other antibiotics failed to cure my UTI, and let me tell you, not only did it not work, but I also had a violent allergic reaction to it. I was suffering from my first UTI (first of many to come sadly). The symptoms went away pretty quickly after taking the first pill but came back after I stopped taking the medicine two days later. From what I remember, I got really sick: chills, high fever, nausea, complete loss of appetite, extreme fatigue, and red patches all over my body, but especially on my arms, legs, and chest. I had swollen lips as the first indication, but as I was young, I didn’t understand it at first. When I went back to the doctor, he said it was a pretty powerful medicine and that he knew beforehand that the risk of allergy was higher than with other medicines. I don’t hold it against him though, it was very frustrating not to find anything that would work to cure this UTI."

• MS ...
• Taken for less than 1 month
• August 24, 2021

For Urinary Tract Infection "Several years ago, I was prescribed a twice-a-day dose for seven days for a UTI. After 3 days, I was in ICU, fighting for my life due to a severe reaction to Bactrim. It started as severe body aches and vomiting, by day 3, I was admitted to ICU for anaphylactic shock. Recently, I was prescribed a different antibiotic (unfortunately can't recall the name) for a tooth infection. After 3 days, I was so very sick, I thought I was dying. I literally thought I had Covid. A voice whispered 'antibiotic', I looked up the ingredients, and it too was a sulfa-based drug. I stopped taking the medication and within a day, I was much better, thank God! So, based on my experience with Bactrim and other sulfa-based drugs, I would rate it a 1 due to my severe allergy. But it did a fantastic job of clearing up the UTI! I now have Bactrim and drugs like it listed as my #1 allergy on my medical records."

• Jdk...
• Taken for less than 1 month
• February 3, 2021

For Urinary Tract Infection "Do not take this medication!!! As per my conversation before, my tongue was peeling, yet it literally blew up. Obviously, I was allergic. However, it’s February, and my UTI is back. I’m petrified after this experience to take anything!! I was prescribed Cefdinir, so we shall see!! Be very cautious with this medication!! Everything seemed fine, and then it all went awry within a couple of days!!"