Cephalexin and Stomach Pain: What Users Say

• dav...
• Taken for less than 1 month
• March 16, 2016

Cephalexin for Skin or Soft Tissue Infection "Had an ingrown toenail infection. Was given 500mg Keflex taken 4 times a day for 7 days. It is working and I have no pain in my toe. However, so far I've had diarrhea, stomach pain, tiredness and weakness, dizzy spells, yellow skin, loss of appetite, nausea, red scratchy eyes. So most of the usual stuff. The long and short of it is my toe will be healed as long as I can deal with the side effects for a few more days."

• 60i...
• March 26, 2016

Cephalexin for Skin or Soft Tissue Infection "With only 4 doses of 500 mg in 3 days instead of 3 a day, my symptoms got progressively worse. Blurred vision, dizziness, rash, leg pain and swelling, heat sensations in legs, muscle pain, back pain, swelling and pain in the stomach, and extreme fatigue. Stopped taking and reported adverse reaction to the pharmacy and will tell the doctor. Very glad I did not take the full dose. Use with caution if you are sensitive to meds."

• Aly...
• Taken for less than 1 month
• April 30, 2018

For Skin or Soft Tissue Infection "Ended up with an infected wound after foot surgery. Was leaking pus and blood from the incision site. Was put on 500 mg 2x a day for 10 days. After the 3rd day, I noticed no more pus, just blood draining. The pain decreased as well. No bad reaction as I usually get very nauseous from other antibiotics, but not Keflex. I made sure to take the dose on time every day and had a small meal 10 minutes before each dose. 2 hours after each dose, I took a double dose of probiotics and was also taking Saccharomyces boulardii (another probiotic, but it is a yeast and is not killed by antibiotics since it is not a bacteria). Did NOT experience any stomach pains, diarrhea, anxiety, lightheadedness like others. Also stopped drinking coffee and consuming sugar while on these antibiotics, bacteria thrive on sugar in the gut, and the coffee makes your body acidic."

• EPa...
• Taken for less than 1 month
• October 27, 2019

For Bladder Infection "I’ll keep my story short... it hurt to pee... the doc said no UTI but gave me this just in case... Symptoms: 1) fever around 100-103 for two days. 2) joint pains all over, and I’m a runner, so they amplified everything. 3) didn’t poop properly. 4) dizziness and headaches. 5) stomach pain. What I find weird is all of that started after I took pill #3. I even went out for a 5-mile run! I felt completely fine, and then it hit me like a ton of bricks. I stopped taking the meds after pill 5 - it’s been 24 hours - and my temp is ~98, and my joint pains are mostly gone. My stomach is starting to hurt now, and pooping just sucks - so painful. I feel like my body went into rejection mode for this. This drug is way too damn strong. Please be careful."

• Mom...
• Taken for less than 1 month
• December 14, 2016

For Skin or Soft Tissue Infection "My 17-year-old son is allergic to sulfa-based antibiotics (he gets hives everywhere), but he keeps getting staph infections (like boils), so this time he was given Cephalexin. He got through his whole 10 days of taking it twice daily, just finished last Thursday. The negative side effects kicked in Saturday, Sunday, and Monday. Stomach pain, chills, fever, tightness in chest, frequent urination, restlessness, anxiousness, and sleeplessness. He's really freaked out about it. The inability to sleep is what's actually most upsetting because it makes you feel more anxious and crazy after a few days. The crappy thing is - he just has to wait and wait until it clears out of his system. Poor kid. This sucks."

• Anonymous
• May 2, 2016

For Skin or Soft Tissue Infection "I had a fungal toenail infection, went to the doctor, prescribed Cephalexin 500 mg cap 2 twice daily. As I have IBS, took it with food to not upset my stomach, 1st 2, no effect, but when I took the next two, thought I was going to die. I woke up at 2 am with severe stomach pain, nausea, dizziness. I was draped over the bathroom counter, thought I was going to pass out. Within 10 mins, my hair was soaking wet and had perspiration running down my face and having diarrhea at the same time. I live alone, 73, was considering calling 911. The next 2 mornings, I saw that my gums had been bleeding, not red but dark purplish-black. As I have dentures, it was inside and between my teeth. Found it can cause gum bleeding. Talked to the pharmacy, said to stop it. Never again."

• Hub...
• Taken for less than 1 month
• April 24, 2018

Cephalexin for Bacterial Infection "Hubby has a bad tooth, recently started hurting him extremely bad. Got hold of a dentist to get the tooth out. He prescribed Keflex 250 mg, for the first 3-4 doses he was to take 2 x 3 doses then 1 cap x 3/day until finished. Within 1 dose, his tooth pain went away, however, on the 2nd to 3rd dose, the nausea, vomiting, horrible stomach pain that he describes as a nasty pain which he has to make himself puke gives him short-term relief. So if he is able to tolerate the rest of the duration of the script, this will be added to his list of meds he can't take."

• Nev...
• Taken for less than 1 month
• August 12, 2018

For Skin or Soft Tissue Infection "I was prescribed Cephalexin 500 mg 3X a day for 10 days. From the first day, I had stomach pain, diarrhea, headache, anxiety, confusion, and heart palpitations. At first, I thought all of these issues were from being sick and lack of sleep. By day two, I knew it was this medicine. I went down to two doses a day, but by day 5, I had to stop taking it. Worst drug ever! The smell of the drug is a cross between a rotting dead animal and rotten eggs, never again will I touch this drug. Usually, I read drug info before starting a drug, but I was so sick I failed to do this first. Going forward, I will not make this mistake. I experienced too many side effects from this drug."

• Poo...
• December 22, 2017

For Bacterial Infection "I am currently on cephalexin 500mg × 4 times a day for my strep throat and UTI. It has completely taken my appetite, so I now have to force myself to eat. My stomach hurts so bad, severe headaches, diarrhea, and hot and cold flashes, and all I want to do is sleep all day. I'm only on day four and have 3 more to go if I can make it."

• May...
• Taken for less than 1 month
• June 21, 2022

For Bacterial Infection "I was prescribed a week's worth of cephalexin, four 500 mg capsules a day for a possible UTI. For the first 2-3 days of taking this medication, I felt like a bloated, dizzy, tired zombie and didn't feel an improvement. For one of those days, I got horrible constipation and indigestion. I couldn't pass gas. It scared me and made me anxious. I began to question whether this medication would actually work for me. I also recommend taking a probiotic with this medication since it does go hard on your digestive system in my experience. Thankfully, by the middle of the 3rd day, I finally felt some relief and started to feel a bit better. I had less pain. Unfortunately, though, the next couple of days were a rollercoaster with the persistent stomach pain and constipation. After treatment, urine tests came back free of infection. I still have some stomach pain, dizziness, fatigue, and some constipation, though hopefully it goes away soon. I will keep treating and healing my stomach with probiotics. Maybe I would try another medication next time."

• Lau...
• Taken for less than 1 month
• August 16, 2020

For Kidney Infections "I went to the ER for a kidney infection, and they prescribed me Cephalexin for 14 days. I am currently on day 10, and my kidneys still hurt. My side effect symptoms are diarrhea, feeling lightheaded at times, and also stomach bloating and pain. I reviewed it with my doctor, and she said to continue for the 14 days. I will come back for a final review."

• Ast...
• January 13, 2016

For Bacterial Infection "Was just starting and took one pill. About 2 hours later, I was experiencing horrid stomach pains and vomiting. I also was in a very confused state. Had to go to the E.R.! Switched to Bactrim and having a much better time."

• Not...
• Taken for less than 1 month
• May 16, 2022

For Skin or Soft Tissue Infection "Prescribed 500 mg 4 times a day for an infected tick bite. From day one, nausea, stomach pain, diarrhea, major headaches, and altered moods. I am on day 5 now, side effects are not any better, and I am feeling depressed. The tick bite site looks like it is healing. I would not take this given another option."

• For...
• Taken for less than 1 month
• August 20, 2017

For Skin or Soft Tissue Infection "The doctor prescribed 500 mg, four times a day for seven days as a treatment for an infected mosquito bite. The first day was fine, but by the second day, I had severe stomach pains, diarrhea, and shortness of breath. I have decided that I will never take this medicine again."

• Anonymous
• Taken for less than 1 month
• August 23, 2022

For Middle Ear Infections "Antibiotics never sit well for me. Especially penicillin, which I now don't take because it makes me projectile vomit and causes so much stomach pain. So because of that (and all the horrible reviews), I was nervous to take cephalexin. But this stuff works. I had a double ear infection and sinus infection. It cleared it all up and caused nothing but some minor stomach pains and nausea that were very manageable. Just eat a good meal with it, and you should be set. One of the best antibiotics I've had to take."

• Rac...
• Taken for less than 1 month
• May 16, 2023

"I have been prescribed 500 mg of Keflex four times a day for 10 days to help clear up a tooth infection that has caused cellulitis on the right side of my face. I was previously on a 14-day course of amoxicillin, but that did nothing. The dentist recommended we now try Keflex. I was apprehensive after reading some of these reviews, but I was also desperate considering the swelling had me looking like Quasimodo. I would love to say that I am having a side effect-free experience with this med, but that is not the case. Within hours of taking my first dose, I experienced stomach pain and bloating. I made sure I took it with a full meal to avoid any nausea or vomiting. The bloating and stomach cramping have continued and have not let up. I’m on day 6 and beyond miserable. I am constipated, bloated, have debilitating stomach pains, and have gained 4 pounds. I’m trying to finish the course, but it’s a struggle. The facial swelling went down by day 4, so that’s a plus."

• ARU...
• Taken for less than 1 month
• January 21, 2020

For Bacterial Endocarditis Prevention "I was prescribed antibiotics after my root canal. The first few days were fine, but midway, I began to experience bad stomach pain with nausea. It’s pretty bad. The only thing that’s helping is chamomile tea."

• All...
• Taken for less than 1 month
• October 1, 2021

For Skin or Soft Tissue Infection "So I took Cephalexin to get rid of an infected cyst. It did the job for the most part, but it may have been less effective since I had already taken it before. I didn’t have the side effects other people had: I didn’t have ANY nausea, stomach pain, drowsiness, or anything with this medicine, and I usually took it without food too. It didn’t really help the second time (after I got my cyst removed and stitches in), but that’s my fault, I was prescribed doxycycline, and I took cephalexin AGAIN instead. Overall, a good experience!"

• Kca...
• Taken for less than 1 month
• October 14, 2019

For Bacterial Endocarditis Prevention "I was prescribed antibiotics for after my root canal. First few days were fine, but midway began to experience bad stomach pain with nausea. It’s pretty bad. The only thing that’s helping is chamomile tea."