Keflex® (Cephalexin Capsules, USP) is a semisynthetic cephalosporin antibiotic intended for oral administration.
Keflex is indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms:
Respiratory tract infections caused by
(Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Keflex is generally effective in the eradication of streptococci from the nasopharynx; however, substantial data establishing the efficacy of Keflex in the subsequent prevention of rheumatic fever are not available at present.)
Otitis media due to
S. pneumoniae, H. influenzae, staphylococci, streptococci, and
Skin and skin structure infections caused by staphylococci and/or streptococci
Bone infections caused by staphylococci and/or
Genitourinary tract infections, including acute prostatitis, caused by
E. coli, P. mirabilis, and
--Culture and susceptibility tests should be initiated prior to and during therapy. Renal function studies should be performed when indicated.
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Keflex and other antibacterial drugs, Keflex should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
Published Studies Related to Keflex (Cephalexin)
Randomized controlled trial of cephalexin versus clindamycin for uncomplicated pediatric skin infections. [2011.03]
OBJECTIVE: To compare clindamycin and cephalexin for treatment of uncomplicated skin and soft tissue infections (SSTIs) caused predominantly by community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA). We hypothesized that clindamycin would be superior to cephalexin (an antibiotic without MRSA activity) for treatment of these infections... CONCLUSIONS: There is no significant difference between cephalexin and clindamycin for treatment of uncomplicated pediatric SSTIs caused predominantly by CA-MRSA. Close follow-up and fastidious wound care of appropriately drained, uncomplicated SSTIs are likely more important than initial antibiotic choice.
Effects of sodium bicarbonate and ammonium chloride pre-treatments on PEPT2 (SLC15A2) mediated renal clearance of cephalexin in healthy subjects. 
PEPT2 mediates the H(+) gradient-driving reabsorption of di- and tri-peptides, and various peptidomimetic compounds in the kidney... This effect was more obvious for the PEPT2*2/*2.
Efficacy and tolerability of once-daily cephalexin in canine superficial pyoderma: an open controlled study. [2008.08]
OBJECTIVES: The aims of this study were to evaluate the efficacy and tolerability of oral cephalexin given at 30 mg/kg once daily in dogs with superficial pyoderma and to compare them with those of oral cephalexin given at 15 mg/kg twice daily. METHODS: Twenty dogs with superficial pyoderma were treated with cephalexin at 30 to 60 mg/kg orally once daily (group A) and compared with 20 dogs treated at a dose of 15 to 30 mg/kg orally twice daily (group B)...
randomized, double-blind, placebo-controlled trial of cephalexin for treatment of uncomplicated skin abscesses in a population at risk for community-acquired methicillin-resistant Staphylococcus aureus infection. [2007.11]
Empirical use of beta-lactam antibiotics, the preferred agents for treating uncomplicated skin and soft tissue infections, may no longer be appropriate for these infections because of the increasing prevalence of community strains of methicillin-resistant Staphylococcus aureus (MRSA)...
Randomized, Double-Blind, Placebo-Controlled Trial of Cephalexin for Treatment of Uncomplicated Skin Abscesses in a Population at Risk for Community Methicillin-Resistant Staphylococcus aureus Infection. [2007.09.10]
Background- Empirical use of beta-lactam antibiotics, the preferred agents for treating uncomplicated skin and soft-tissue infections, may no longer be appropriate for these infections because of increasing prevalence of community strains of methicillin-resistant Staphylococcus aureus (MRSA)...
Clinical Trials Related to Keflex (Cephalexin)
Comparison of Cephalexin Versus Clindamycin for Empiric Treatment of Suspected CA-MRSA Skin Infections [Recruiting]
The purpose of this study is to help define the role of antibiotics in the treatment of
pediatric skin infections caused by CA-MRSA. We hypothesize that treatment with cephalexin,
a penicillin-like antibiotic to which CA-MRSA would be expected to be resistant, does not
result in poorer outcomes than treatment with clindamycin, an antibiotic to which CA-MRSA is
most often susceptible.
A Study to Compare Cefdinir and Cephalexin for the Treatment of Mild to Moderate Uncomplicated Skin Infections [Completed]
The purpose of this study is to compare the efficacy and tolerability of cefdinir to that of
cephalexin in patients with mild to moderate uncomplicated skin/skin structure infections.
Comparison of Intravenous Cefazolin Plus Oral Probenecid With Oral Cephalexin for the Treatment of Cellulitis [Recruiting]
The purpose of this study is to determine whether oral cephalexin is equivalent to
intravenous cefazolin plus oral probenecid for the treatment of uncomplicated skin and soft
tissue infections in patients that present to the emergency department.
Strategies Using Off-Patent Antibiotics for Methicillin Resistant S. Aureus "STOP MRSA" [Recruiting]
The purpose of this study is to determine the optimal outpatient treatment strategy of
uncomplicated skin and soft tissue infection (SSTI) in areas of the United States where the
prevalence of Community-Acquired Methicillin-Resistant Staphylococcus (S.) aureus (CA-MRSA)
is high. Infection with the S. aureus bacteria that is resistant to antibiotics is a cause
of SSTIs. Three oral antibiotics will be tested for off patent treatment. Patients will
receive Trimethoprim/Sulfamethoxazole (TMP/SMX), placebo (substance containing no
medication), clindamycin, or cephalexin or some combination of these. The study population
will include 2,235 volunteers, children 13 years of age and over and adults presenting to 5
large urban Emergency Departments. Therapy for acute uncomplicated SSTIs, including abscess,
infected wound, and cellulitis will start on the day of enrollment. Participants may be
involved in study related procedures for about 9 weeks.
The Placebo Effect May Involve Modulating Drug Bioavailability [Not yet recruiting]
The total effect of a medication is the sum of its drug effect, placebo effect (meaning
response of placebo), and their interaction. Current interpretation of clinical trials (the
gold standard of evidence-based-medicine) assumes no interaction, and the mechanism(s)
underlying such interaction have not been fully explored. One possibility is that the
placebo effect may modulate drug bioavailability. Using caffeine as a model drug, we have
recently shown that the placebo effect of caffeine ingestion prolongs caffeine half life.
Due to the novelty of this finding and its important clinical practice and clinical research
implications, it needs to be confirmed in another set of subjects and extended to additional
The results of the study are expected to further our understanding of the mechanism of
action of a widely used medical intervention, i. e., placebo. The results will be important
for both clinical practice and clinical research.
Reports of Suspected Keflex (Cephalexin) Side Effects
Drug Hypersensitivity (41),
Drug Ineffective (9),
Staphylococcal Infection (5),
Adverse Drug Reaction (4),
Urticaria (4), more >>
PATIENT REVIEWS / RATINGS / COMMENTS
Based on a total of 14 ratings/reviews, Keflex has an overall score of 4.86. The effectiveness score is 7.71 and the side effect score is 6.57. The scores are on ten point scale: 10 - best, 1 - worst. Below are selected reviews: the highest, the median and the lowest rated.
Keflex review by 43 year old male patient
|Overall rating:|| || |
|Effectiveness:|| || Considerably Effective|
|Side effects:|| || No Side Effects|
|Condition / reason:|| || post surgery antibiotic|
|Dosage & duration:|| || 500mg taken one cap 3 x day for the period of week|
|Other conditions:|| || depression|
|Other drugs taken:|| || noone|
|Benefits:|| || removed bacteria from a rather invasive surgery that could have encountered complications which could lead to other serious side effects|
|Side effects:|| || None - i experienced no side effects and was very happy with the results. Will use this product again if i need to.|
|Comments:|| || Taking One capsule 3 times per day to combat infection and I found it to work effectively|
Keflex review by 40 year old female patient
|Overall rating:|| || |
|Effectiveness:|| || Ineffective|
|Side effects:|| || Severe Side Effects|
|Condition / reason:|| || infected lymph node|
|Dosage & duration:|| || don't remember (dosage frequency: twice daily) for the period of 5 days|
|Other conditions:|| || none|
|Other drugs taken:|| || none|
|Benefits:|| || there were no treatment benefits in taking this drug|
|Side effects:|| || i broke out into hives all over my torso|
|Comments:|| || i was seen in the doctor's office for a swollen lymph node in my groin. at first i was told to use warm compresses; this didn't work, so they put me on an antibiotic (keflex) and within 2 days i had broken out into hives all over my torso, and the lymph node did not decrease at all in size. it was still red, swollen, and painful. i then heard about lymph drainage, done by a certified massage therapist. went for one session. by the end of the session, my lymph node was smaller, no longer red, and no longer painful; within a day after the session, the lymph node was no longer swollen.|
Keflex review by 54 year old female patient
|Overall rating:|| || |
|Effectiveness:|| || Highly Effective|
|Side effects:|| || Severe Side Effects|
|Condition / reason:|| || tooth infection|
|Dosage & duration:|| || 500mg taken 1st course: 3x day, 2nd course, 2x day for the period of 9 days, then 2 days|
|Other conditions:|| || hypothyroid, mitral valve prolapse|
|Other drugs taken:|| || Synthroid, estrogen, darvocet, 1 small dose immodium|
|Benefits:|| || Really cut down the tooth infection/pain and swollen glands, during the first course of treatment I did not have any side effects at all.|
|Side effects:|| || Severe diarrhea, very severe vomiting|
|Comments:|| || I was given keflex (3x daily) for an infected root canal that needed to be redone. The swelling, pain and swollen glands subsided substantially while I was waiting 2 weeks for my appt to have the root canal redone. After the root canal, the dentist put me back on the keflex (2x daily) to insure against further infection, also since I have mitral valve prolapse. After 2 doses I developed diarrhea and took .5mg of immodium (I am sensitive to immodium, only need a very small dose). 8 hours later I developed worse diarrhea and then very severe vomiting, stomach pain, severe headache, dizziness, chills. Also my muscles were shaking and cramping as if I was very cold. I had to be taken to the urgent care, received an injection of phenergan which helped, and told never to take keflex again. Flu test was negative, I had not eaten anything during that day which could have caused food poisoning. Dx: gastroenteritis caused by keflex.|
Page last updated: 2011-12-09