Cephalexin and Headaches: What Users Say

• Ste...
• Taken for less than 1 month
• May 2, 2021

For Bacterial Infection "Just took the final dose. I am praying I will feel like myself again. I slept the first 4 days (15 hours at a time). Day 5: Mild to moderate to paralyzing anxiety and depression (I am on anti-anxiety medication, I take an antidepressant daily). By day 7, intense headache that didn’t respond to Acetaminophen. I am crying as I feel confused and have insomnia. I hope the person that simply posted insults here gets the help they need. Prayers for a person who enjoys being rude for a hobby. NO ONE has the right to shame all who post here. ONLY a very sad soul bullies those (including me) that post voluntarily and in a clear, concise manner here. Taking time and effort to post side effects and symptoms of an antibiotic can be a valuable tool for those who may not realize why they are feeling bad. We live in an era that knows “it’s in your head” is fodder for an ignorant person."

• Fat...
• Taken for less than 1 month
• June 6, 2020

Cephalexin for Bladder Infection "So I ended a Saturday at the ER. I ended up having a urinary infection, a severe one. The PA prescribed Keflex 500 mg for 7 days - it really helped after 2 days, but I noticed that it does bring out side effects on myself. I feel nauseous, tired, agitated, eyes feel hot, headaches. Even though I took 2 Advil, it was still there. I also feel super anxious, I've been having mood swings, I feel more sad, and somehow more depressed than I have been in the past. And I still have one more day to go."

• Jea...
• Taken for less than 1 month
• May 28, 2019

Cephalexin for Bladder Infection "Took a 500 mg dose of Keflex twice a day for one week - I had a UTI. Side effects were diarrhea, headaches, felt depressed, upset stomach, and nausea. Now I’m having stomach cramping. Just hope the urinary tract infection I had is gone after taking this strong antibiotic."

• Kat...
• February 21, 2017

For Bladder Infection "Was experiencing pressure in the lower abdomen and urge to urinate frequently (approx 2 x's per hour sometimes more). Tried amoxicillin, which did nothing. Was given cephalexin 500 mg 2 x's daily. First 3 days noticed a change. Only issue was a headache. Day 4, urination frequency was decreasing (once every 2-2 and 1/2 hrs) and most pressure/pain was gone. Continued to drink water, cranberry juice, and kefir to restore good bacteria and prevent yeast infection and/or another uti. Apparently, it's common for it to recur due to wiping out positive bacteria. Will finish 7-day regimen and start taking 'Friendly Flora' in hopes of preventing future issues. I believe this antibiotic is working great and hope it knocks out infection completely."

• Nev...
• Taken for less than 1 month
• October 21, 2020

For Bacterial Infection "I’ve been on this drug multiple times before for UTIs and had manageable side effects, usually headache and fatigue. This time I was put on it for a suspected bacterial infection. I took it for 3.5 days and increasingly had a severe headache, unbearable anxiety, and tachycardia requiring beta blocker usage. I don’t even know if anxiety is the right word, I literally feel like I’m on a hallucinogen or something, and sleeping has been impossible because of this feeling and the racing heart. It feels like a constant adrenaline surge I have no control over. Very weak as well, last night I felt like I couldn’t move my legs and almost went to the ER. I’ve been off of it for a couple of days now and finally slept last night, but still don’t feel right in my head. Will never take this again, I feel like I’m in hell."

• Nev...
• Taken for less than 1 month
• October 21, 2020

For Bacterial Infection "I’ve been on this drug multiple times before for UTIs and had manageable side effects, usually headache and fatigue. This time I was put on it for a suspected bacterial infection. I took it for 3.5 days and increasingly had a severe headache, unbearable anxiety, and tachycardia requiring beta blocker usage. I don’t even know if anxiety is the right word, I literally feel like I’m on a hallucinogen or something, and sleeping has been impossible because of this feeling and the racing heart. It feels like a constant adrenaline surge I have no control over. Very weak as well, last night I felt like I couldn’t move my legs and almost went to the ER. I’ve been off of it for a couple of days now and finally slept last night, but still don’t feel right in my head. Will never take this again, I feel like I’m in hell."

• Lyn...
• June 8, 2019

For Skin or Soft Tissue Infection "Cephalexin got rid of the infection, but I had horrible side effects. I took it for 4 days, at a dose of 500 mg, 4 times a day. I had horrible headaches, diarrhea, major depression, dry and bloodshot eyes, nausea, was very tired, and didn't have motivation to do anything. Anxiety, joints were on fire! Stopped a day ago and still feel awful! Won't take it again because of side effects."

• NJD...
• February 14, 2010

For Skin or Soft Tissue Infection "I had cellulitis on my lower leg. I was prescribed Cephalexin 250 mg tabs four times a day for 10 days. I saw mild relief at the end of day 2, and by day 5, the infection was on its way down (less swollen, less hot, less sensitive). I continued the medication through day 10, and it did not return. I did not have any headaches, swollen joints, etc., that others reported. I am allergic to penicillin but do not have cross-sensitivity to cephalosporins."

• Mor...
• Taken for less than 1 month
• November 24, 2018

For Skin or Soft Tissue Infection "I had a staph infection in my nose, so my doctor put me on a week of cephalexin, 500 mg 3x daily. I was worried about GI side effects but was absolutely fine. The only side effects I noticed were very, very minimal fatigue and the slightest headache that was barely noticeable. I also took a once-daily probiotic with my dose in the evening just for peace of mind."

• Abb...
• Taken for less than 1 month
• June 26, 2019

For Skin or Soft Tissue Infection "Horrible medicine. My doctor prescribed me cephalexin for an infected boil that I burst and got infected. I was told to take 4 tabs, 500 mg daily for 7 days. I'm a lupus patient already taking plaquenil 400 mg daily. Anyway, I went after 7 days, the infection wasn't healed yet, so my doctor told me to continue for 10 more days. But when I started to continue, I got a horrible rash all over my arms and neck. Along with this, I got continuous headaches, so I stopped the medication. But the rash is still there, and I'm getting blisters on my body. Thinking of going to the emergency room."

• Sam...
• June 23, 2021

Cephalexin for Bladder Infection "I've always taken ciprofloxacin for my chronic bladder infections, but this time around my doctor said he can't give it to me because of a new study that has nothing to do with me. So... I get Keflex. It's extremely slow at getting to the infection. I'm on day three, and I'm just now starting to feel a little better... I think. It also gives me horrific heartburn, headaches, fatigue, and I can't poop."

• Tes...
• Taken for less than 1 month
• July 8, 2019

Cephalexin for Acne "I started taking this medication initially for an infection from a bug bite. After three days of being on the medication, I noticed all of my skin is clear and appears to be glowing, and my pores have shrunk so much. I’m in my early 30s and still suffer from acne occasionally, mostly hormonal acne, and this is amazing. I don’t want to get off of it now. I was on doxycycline for months in my early 20s, which also had a similar effect. The only side effects from this medication initially were a headache and diarrhea, but that went away after one day, and I’m staying on probiotics to help regulate."

• cur...
• Taken for 5 to 10 years
• March 2, 2022

Cephalexin for Bladder Infection "I have been prescribed Keflex since they stopped using Cipro for that a few years ago. Works great every time and works within hours. Makes me a little tired and I have a bit of a headache, but I think that might have to do with my body trying to heal itself. I always ask for it if it will treat the bacteria that caused my UTI. They won't prescribe this for some bacteria... FYI. I like that this drug has been around for years and years. Makes me feel safer about taking it."

• 42y...
• Taken for less than 1 month
• May 9, 2017

For Bladder Infection "The first day I took it, my skin felt flushed, and I had a bad headache and dizziness (almost chickened out then). But these effects improved as I continued to take the medicine. I was prescribed 500 mg three times a day for 5 days for trace leukocytes in my urine. I've never taken cephalexin before, and I'm very sensitive to medications (slow metabolizer) and already cannot take several antibiotics due to allergies (cipro, nitrofurantoin, and sulfa). So I'm thankful that I seem to be okay with the cephalexin (I'm running out of antibiotics that I can take!). I haven't noticed any other side effects, not even diarrhea. As for my symptoms, some have improved, but not all. I only have 2 pills left, but not all of my symptoms went away yet. I hope it works."

• 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."

• Emm...
• Taken for less than 1 month
• July 21, 2016

For Kidney Infections "Had cephalexin through IV and now on day 3 of ten days of twice-a-day oral tablets. 500 mg for kidney infection. I'm also pregnant. I usually react horribly to antibiotics, this one, so far, is not so bad. All my symptoms relieved after the second day. I do have headaches from this med and sensitivity to light. But so far, so good. I recommend it, but it gets a lower rating due to my headache :("

• ArI...
• May 11, 2011

Cephalexin for Acne "After taking doxycycline for a while, my body became resistant to it, so my dermatologist switched me to Keflex for acne. I think I had at least five bowel movements the first day. Eventually, my digestive system became somewhat regular, but then I started getting headaches on a regular basis. It cleared up my acne somewhat, but it was definitely not worth all the side effects."

• cys...
• February 21, 2009

For Skin or Soft Tissue Infection "I get blurry vision and mild headaches when I take cephalexin. But I get golf ball-sized cysts on my face, and cephalexin really helps. I just had one developing and started taking it before it got out of control; helped so much. I can at least still go to work."

• Bro...
• March 6, 2018

For Skin or Soft Tissue Infection "I went on cephalexin for the beginning of a staph infection caused by an ingrown hair on my bikini line. I'm currently on day 5 of my 7-day treatment, and my infection is fully healed. Pleasant experience overall; no side effects besides headaches the first 2 days, but minor; pain relievers not needed. However, I didn't consume alcohol or caffeine for the entirety of the treatment as I was advised that cephalexin enhances side effects caused by alcohol and coffee, such as drowsiness, dizziness, upset stomach, etc. I had a chai drink containing a very little amount of caffeine; I got dizzy and very anxious within the hour of drinking it. It never happened to me before despite countless times having the drink, so I related it to the drug, further exemplifying how much the medication enhances both physiological and neurological effects of substances such as caffeine. I recommend this medication, but use with caution: no caffeine or alcohol."

• 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."

• Ash...
• August 6, 2014

For Skin or Soft Tissue Infection "Was given 500 mg 3 x daily for 10 days for pimple-like rash bumps all over body and for a bladder infection. Today is my first day, already experiencing ringing in ears, diarrhea, blurry vision, and a headache. Not too thrilled, I guess I'll have to play this out carefully."

• 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."

• Kea...
• April 14, 2019

For Kidney Infections "Was put on cephalexin for a UTI, 500 mg twice a day for 7 days. Have just finished it after a horrendous experience. Very bad indigestion, anxiety, diarrhea first day, then constipated. Fatigue and headache. Shakes with hot and cold periods. After a day of finishing, the diarrhea has returned. Will never take this medication again."

• Fee...
• Taken for less than 1 month
• October 16, 2017

For Bacterial Infection "I saw a doctor, and he gave me this: take 4 daily for a week! I'm on day 6, and I feel so lost and can't even think straight. It had diarrhea and I feel so tired where I can't even stay up without wanting to just close my eyes, and also dizzy and headaches. I think I got a high dose for something kind of little. I have this small blister from breastfeeding, and the doctor must have thought it was something else, but so far it kind of helped heal it. But the side effects are so bad. I'm going back to the doctor because I can't take these meds anymore. I hate this feeling."

• Lov...
• Taken for less than 1 month
• July 4, 2021

For Skin or Soft Tissue Infection "I was prescribed this drug, 500 mg, for 7 days after rhinoplasty to prevent infection. If taken without food, I get nauseous and vomit, it also leaves a metallic taste in your mouth all day. I was also prescribed opioids, and that didn’t even cure the headaches from this drug. I am an emotional mess, crying all the time for no reason, insomnia and super fatigued, vivid nightmares, also, day 4, I got a horrible yeast infection. This is my last day, and I truly hope that I go back to normal. The depression and anxiety is the worst. Since it was not taken for a condition but for preventative purposes after surgery, I'm not sure if it worked, but the side effects are horrendous! Hope I never have to take this ever again!"