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Sulfamethoxazole / trimethoprim and Chills: What Users Say

Brand names: Bactrim, Bactrim DS, SMZ-TMP DS, Co-trimoxazole, Septra, Septra DS, Bactrim Pediatric, Bactrim IV, Bethaprim Sulfatrim Pediatric Bethaprim Pediatric …show all brand names

Chills: mentioned by 126 users (7.3%)

Based on user experiences from 1,720 Sulfamethoxazole / trimethoprim reviews, the following table shows the most commonly mentioned side effects.

All user comments are moderated by Drugs.com. Each review is verified for relevance and screened for inappropriate content. Side effects are user-reported and not clinically verified.

nausea 24.5%
headaches 19.1%
anxiety 11.8%
dizziness 9.4%
rash 8.9%
loss of appetite 7.6%
chills 7.3%
fever 7.2%
insomnia 7.2%
vomiting 6.2%

Reviews for Sulfamethoxazole / trimethoprim

Commonly mentioned side effects
  • Liz...
  • Taken for less than 1 month
  • March 22, 2016

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Take a breath. If you're speeding through all of these experiences, you're probably looking for potential side effects and reactions of other people. I know because I'm just like you. I can tell you the first day I took Bactrim, I had a horrible migraine. The worst I've had in months. But guess what? I also didn't drink coffee that day after having a constant intake for weeks. I had other problems like chills, but wait, I got this medicine for an infection! So many symptoms people experience are likely a result of other things. My UTI went away. I drank lots of water and milk with it. Other than experiencing a few more headaches and a bit of tiredness, I was fine."

8 / 10
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  • Vga...
  • Taken for less than 1 month
  • December 18, 2019

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Had not read side effects, so did not realize what I felt was caused by the med. My first day on Bactrim, I had side effects of feeling achy and depressed. By day 3, I was shaking, shivering, anxious, and insomnia. By day 5, nausea, dizziness, 100 heart rate, very low blood pressure, extreme anxiety. Pain everywhere, pain in my kidneys, very dehydrated, painful muscle spasms. Day 6, was going to go to the emergency room when I realized it could be the Bactrim and read side effects. Find it difficult to believe a doctor would give this to anyone. It was horrible."

1 / 10
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  • Bja...
  • Taken for less than 1 month
  • November 4, 2019

Sulfamethoxazole / trimethoprim for Bacterial Infection "Worst medication ever. My anxiety is through the roof. I am freezing most of the time when I’m not drenched in sweat. Heart rate is racing. Can’t sleep due to the horrible feeling of not waking. It’s like the spins but different. I swear I was seeing the light! I would be listening to my husband tell me to drink the water next to me, but I couldn’t respond or move. It was like I was paralyzed. Very terrifying. If at all costs, please find an alternative antibiotic. I wouldn’t wish this on my worst enemy... pure torture. I am prescribed it for 14 days twice daily, and I’m only on day 3."

2 / 10
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39 Report

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Frequently asked questions

  • Anonymous
  • Taken for less than 1 month
  • March 13, 2020

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "This drug is terrible! Run if the doctor prescribes this. Day 1, I had a headache and aches to my kidneys. Like I could literally feel the pain in my kidneys! I felt bloated, vomiting, fever of 101, pain in my kidneys, jittery, and chills. Please, please don't take it. The ratio of the ones that had no symptoms to the ones who did is a big difference! I took it for 2 days, then threw the rest down the toilet. The ONLY good thing was I took 1 dose, and the next day felt relief... but still... eff this stuff!"

1 / 10
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  • Ash...
  • Taken for less than 1 month
  • November 16, 2017

Sulfamethoxazole / trimethoprim for Kidney Infections "I was a bit of a moron and let a UTI go for too long. I had pain on and off for a few months in my back. Pee was cloudy, frequent urination... all that good stuff, but two days ago, I woke up and felt absolutely terrible. I was so nauseous, couldn’t eat anything, awful headache, chills, and the worst back pain I had ever felt. I went to the doctor, and she wrote this for me. I took two pills yesterday, and already today I feel a hundred times better. I don’t believe it is for everyone, obviously, due to the mixed reviews, and my mother had taken it before, and it had awful effects on her as well, but I do believe it’s worth trying because for me, it’s been wonderful. I couldn’t even bend over yesterday, and today all I have is slight dull pain in my back. Worked perfectly."

10 / 10
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  • Tld...
  • February 27, 2021

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Day 1: Prescribed 1 pill twice a day for 7 days. The medication seemed to be working, and I was urinating like normal. Day 2: That night, I ended up experiencing terrible pain on the inside and outside of my vagina, such as burning, itching, redness, and swelling. I thought it could be a reaction, but I wasn’t sure. Day 3: That morning, I ended up experiencing the same terrible pain, but it was more severe. At this point, I could hardly move, sit, or stand without it hurting. It felt like ulcers on the inside and outside of my vagina due to the terrible burning sensation. That night, the pain got even worse. I ended up having chills and body aches, possibly a low-grade fever. Day 4: I stopped taking the medication. I decided that this medication is not worth the symptoms and advised my doctor that I would not be continuing the medication. If I could rate my symptoms on a scale from 1-10, I would rate it at a 15. I will NEVER take this medication again."

1 / 10
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  • Mic...
  • Taken for less than 1 month
  • September 12, 2018

Sulfamethoxazole / trimethoprim for Bacterial Skin Infection "I'm thinking some of the side effects commented were possibly results of the condition and not the medication. I have MRSA. Of course, I have chills because the abscess is a massive infection. One person mentioned organ failure. MRSA entering the bloodstream would do that too. So far, so good here - still early on. I was on clindamycin for a tooth abscess. I must have been unknowingly treating a mild staph infection. When the clindamycin stopped, the bacteria became aggressive. Now here I am on Bactrim. One sore has lightened in color and pressure within 24 hours. The other sores still hurt, so I took ibuprofen. You won't get headaches if taken with a pain/fever reducer. The clindamycin wrecked my gut, but I actually haven't had a hard time with the Bactrim. I've been sure to eat something or drink a glass of milk before taking it."

7 / 10
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  • Ano...
  • Taken for less than 1 month
  • September 26, 2018

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "I was prescribed this for a UTI. Worst experience ever! Got up to day 4 of taking it and started to feel weak, confused, had really bad back and neck pain, pain when I walked. I also had watery, itchy, burning eyes, a massive headache, sleepy and fatigue, and like a tight chest. At night, I couldn't sleep, had the chills and a cold sweat. I have lost my appetite and have lost 6 pounds in just 4 days! I have stopped taking them but now I am developing a rash on my body that really itches. Please, people beware of this. My advice is to ask for something else, or at the first sign of a symptom, stop taking."

1 / 10
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  • hor...
  • Taken for less than 1 month
  • May 4, 2019

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "I will never take Bactrim again, despite the fact that it appears to have cleaned up my UTI. I was prescribed 6 pills, 2 per day for 3 days. By pill #2, I lost my appetite and felt very weak and tired. Went to bed very early. As I continued the medication, I developed many flu-like symptoms and spent the next 4 days in bed. Chills, achiness, lethargy, listlessness, extreme tiredness, brain fog, inability to stand up for very long without feeling woozy, not even able to sit up and do light work indoors. This medication had me flat in bed for 4 days straight. Two days after finishing the medication, I have still not regained my strength completely, although I am starting to normalize. I am typically a very active person who works outdoors every day. This one threw me for a loop - never again! I will ask for something else for a UTI."

1 / 10
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  • Lyn...
  • Taken for less than 1 month
  • May 12, 2019

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Have taken Bactrim for frequent UTIs in the past with no side effects. Last night I took the first dose of Bactrim DS for yet another UTI; within 10 min, my vaginal area and lips were itching. Took antihistamine and went to bed. This morning my lower lip is very swollen/red, eyes are bloodshot, and have a round red rash on my upper arm. As the morning continued, I felt major flu-like symptoms: chills, fatigue, muscle/joint pain, headache - like death warmed over. Took aspirin for the pain and went to bed until the intense cold feeling left. The symptoms have abated except for the swollen lip, itchy eyes, and red rash. No idea why I had a reaction this time but will discuss it with my doctor. UTIs are bad enough without then getting very ill from the medication."

2 / 10
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  • Poo...
  • Taken for less than 1 month
  • February 13, 2020

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Took Bactrim for a UTI for 7 days. On the 6th day, had chills and body aches. Literally could not get off the couch. Went to the doctor and was negative for the flu, and the UTI was gone. Got worse (headache, severe body aches, nausea, diarrhea, no appetite-honestly the worst I've EVER felt) and ended up in the ER for fluids. Stopped taking it 2 days ago and am still feeling effects. Be careful-wished I had stopped taking it at the first sign of stomach discomfort. Glad it's a reliable drug for some, but for me, it was horrid."

1 / 10
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  • Bre...
  • August 16, 2016

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "I called the doctors due to weird symptoms after my 5th day of taking this medication. This concludes (chills, nauseous, diarrhea, headache, and even numbness throughout my entire face, lips, and mouth, and the shakes). The pain I get from my UTIs (burning sensation, hard to pee, and hurts). I felt like Bactrim made my pains worse, the burning was 100x worse! I felt as if I was dying!!!! I even had severe insomnia up until 6-7 am! Called the doctors and they said I should have called when the headaches and shakes came along! Cut me off it immediately and prescribed me Macrobid instead. Hope it helps!!"

1 / 10
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  • tdu...
  • July 3, 2017

Sulfamethoxazole / trimethoprim for Kidney Infections "I will not ever take this medication again (generic form of Bactrim DS). I landed in the ER with a severe kidney infection... was given antibiotics, nausea medication, and pain medication through an IV. Went home six hours later and started the Bactrim that night. I woke up at 2 am absolutely drenched head to toe in sweat, with chills... couldn't fall back asleep. The next day I had the worst headache... terrible, terrible pain in the base of my skull, and a horribly stiff and sore neck. Any time I stood up I could feel my blood pressure in my head sore, just throbbing. I had zero appetite. I stopped the Rx after 2.5 days. I felt worse after I started the Rx than before it. Never, ever again."

1 / 10
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  • Bat...
  • Taken for less than 1 month
  • March 27, 2020

Sulfamethoxazole / trimethoprim for Bacterial Skin Infection "I have MRSA from a piercing and was put on Bactrim (2 in the morning, 2 in the evening) 4 days ago. After 2 days on it, I took myself to the hospital. I have never felt this horrible, I swear I feel like it's going to be the end of me. It started out with a bad headache, no appetite, a little dizzy. Right now, I'm sitting on the bathroom floor waiting to throw up, I didn't sleep for even a minute last night even though I was exhausted. I can't stop shivering and shaking, I'm so hot but not running a fever-unbelievable headache. My doctor said this is the only medicine that will help MRSA, and I'm dumbfounded. Is this medication even worth it? I don't know if these feelings are the medication working or not."

1 / 10
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  • Nat...
  • Taken for less than 1 month
  • August 17, 2019

For Bacterial Infection "I took Bactrim for 1.5 days and stopped when the pain in my hips and lower back started. Then later, fever and chills, weakness, jaw stiffness, minor headache and neck ache, then overnight, severe diarrhea and nerve jolts shooting up from my hips. The next morning, my thighs ached, like it was moving down from my hips, minor head and neck ache, ribs felt sore. I still had hip pain and lower backache. I felt like this drug was killing me, not knowing what the heck was happening to my body, my organs. All this after only 3 pills in a super healthy, 57-year-old female body. It has been 2 weeks since I stopped this awful med and still have some hip pain but no stiffness. It is okay if I sit still usually and worse if I exercise. These and other symptoms are not the allergic reactions or side effects listed for this med, they are far more severe. Why is this drug on the market???!!!!"

5 / 10
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  • jro...
  • Taken for less than 1 month
  • September 22, 2018

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Never again! I was put on this for 3 days-2 pills a day for a UTI. I was laid up in bed for 4 days. I was extremely nauseous, chills, sweats, headache, dizzy, couldn’t eat a single thing, and after day 2, I got a SEVERE yeast infection. The pain was unlike anything that has ever happened to me. I took 2 trips to the doctor and over a week to feel somewhat normal again down there. This was way too strong and unnecessary for a simple UTI infection. Never will I ever take this again. I wish I could give it a zero, I am still having nightmares about this drug."

1 / 10
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  • Bac...
  • Taken for less than 1 month
  • September 22, 2020

Sulfamethoxazole / trimethoprim for Bacterial Skin Infection "Prescribe Bactrim 2 days for 10 days for a stye. On the 7th day, I had my allergic reaction. All-over body rash, fever, chills, severe leg pain, chemical burns/ulcers in all soft tissue areas (nose, eyes, mouth, and 'down below'...), abdominal pain, diarrhea, zero appetite, headache, nausea, elevated kidney function test. Bactrim is known and has a long history of hurting more than helping. Stay away!!"

1 / 10
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  • Vin...
  • July 31, 2016

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "I've just finished my treatment for a urinary tract infection. I no longer have any symptoms from the infection. The first 8 days of a 15-day treatment were fine with no side effects. Beginning the 9th day, I began experiencing a mild rash and itching, which seemed to begin on my chest and neck and migrated to my back. A bit of a nuisance but tolerable. Around the 11th day, I began to experience mild joint and muscle aches and a tender scalp around the base of the skull. Acetaminophen and ibuprofen have helped to overcome this, but by the 14th and 15th day, I felt like I had the flu, with no nausea but a loss of appetite. I took the last pill this morning, and by 1 PM, had to lay down with chills, aches and pains, headache, and a slight fever."

6 / 10
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  • Lu1...
  • May 30, 2017

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "I had a UTI, finished an entire prescription of Macrobid. I noticed as soon as I finished the meds, my UTI symptoms came back - so it didn't work for me. I then tried Bactrim. The pain went away after 1.5 days of being on Bactrim, which was a huge relief, but it is now day 4 and I am suffering from nausea, cold sweats, chills, insomnia, and anxiety. It works for your UTI, but the side effects are unbearable after a few days."

5 / 10
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  • Anonymous
  • June 8, 2016

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "My experience was horrible! Prescribed 2 pills a day for 3 days. After the last pill, I started feeling strange and had severe headaches from the time I started taking it until a week later. I didn't think much of it until I went home from work and didn't leave the couch. I had no appetite, constipated, sweating and chills. I wanted to puke, my eyes hurt so bad. Couldn't shake whatever was going on and drank as much water as possible. My body was sore, I slept almost an entire weekend away. I can't tell if my UTI is completely gone or not because I'm still constipated and it hurts! I've never had an antibiotic like this, and I never want it again! All my doc told me was to keep pushing fluids and eat yogurt. Good luck, people."

3 / 10
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  • Jan...
  • May 10, 2019

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "Took Bactrim for a UTI. I had never taken it before. At day 3, I started feeling horrible, short of breath, and intense stomach pain. I had never had a UTI before, so I assumed this might be just a bad UTI. Day 6, I was shaking with chills and could not pee AT ALL. Went to the ER, I had a fever, high eosinophils, and a very elevated creatinine. Turns out I had an acute kidney injury from Bactrim. I was given fluids, and I woke up the next morning covered in the most painful drug rash. That rash lasted two weeks. Not to mention, I was put on prednisone for the rash and because I had interstitial nephritis. The prednisone drove me out of my mind. Awful experience."

1 / 10
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  • Fel...
  • December 12, 2009

Sulfamethoxazole / trimethoprim for Bacterial Infection "I was on Bactrim for 10 days because of a Bartholin cyst that tested positive for MRSA. On the 7th day, I started experiencing back pain, intermittent low-grade fevers, chills, complete fatigue, and eyeball pain. An I.D. doctor wanted me to take it for another 7 days as a precaution, but I had to force him to listen to my symptoms, and he told me to stop taking the Bactrim. Also, don't know if it matters that I'm not of 'normal' weight for most women, at 5'5", I'm 109 lbs - the symptoms I experienced were also listed as possible 'overdose'... stopped Bactrim today - feel terrible."

4 / 10
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  • Hhh...
  • November 15, 2018

Sulfamethoxazole / trimethoprim for Bacterial Infection "I’ve been taking this and am randomly getting anxiety and a jittery feeling. I also keep having weird dreams since I’ve been on it. I had an ear/near my tooth infection. I’m allergic to amoxicillin, so I was prescribed Bactrim. I’m on the 8th day, and I feel insomnia and anxiety. My feet are also really cold. It fluctuates, but I’ll be quitting tomorrow since I don’t feel like myself."

3 / 10
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  • Anonymous
  • December 16, 2015

Sulfamethoxazole / trimethoprim for Urinary Tract Infection "I was prescribed Bactrim for a very painful UTI that I could not flush out naturally with water and cranberry. My UTI pain subsided after about 5 hours of the first dose of Bactrim, which is great. However, the side effects are not so pleasant. I have had chills, mild diarrhea, vivid nightmares/dreams, and extreme migraines. I am on day 3 of a 7-day prescription, but I am contemplating stopping after day 4 or 5 if the side effects continue. The side effects are still not as bad as the UTI pain!"

8 / 10
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  • Anonymous
  • May 10, 2011

Sulfamethoxazole / trimethoprim for Bacterial Infection "This medicine is working for me, but it makes me feel horrible. I've been shaking, have had a rapid heart rate, nausea, extremely thirsty, chills (no fever), dizziness, and cold hands and feet. I did find that taking probiotics helps. It doesn't take away everything, but it helps with the nausea. The only reason I continue to take it is because the doctor said this could be MRSA."

5 / 10
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