Keflex
Keflex Uses, Dosage, Side Effects, Food Interaction and all others data.
Keflex is a semisynthetic analogue of Cephalosporin C. It kills bacteria by interfering in the synthesis of the bacterial cell wall. Peptidoglycan is a heteropolymeric structure that provides the cell wall with mechanical stability. The final stage in the synthesis of peptidoglycan involves the completion of the cross-linking and the terminal glycine residue of the Pentaglycine Bridge is linked to the fourth residue of the pentapeptide (d-alanin). The transpeptidase enzyme that performs this step is inhibited by penicillins and cephalosporins. As a result the bacterial cell wall is weakened, the cell swells and then ruptures. Keflex is a first generation cephalosporin that is active by mouth.
Keflex (also called Cefalexin) is a first generation cephalosporin antibiotic. It is one of the most widely prescribed antibiotics, often used for the treatment of superficial infections that result as complications of minor wounds or lacerations. It is effective against most gram-positive bacteria through its inihibition of the cross linking reaction between N-acetyl muramicacid and N-acetylglucosamine in the cell wall, leading to cell lysis.
| Trade Name | Keflex |
| Availability | Prescription only |
| Generic | Cephalexin |
| Cephalexin Other Names | Cefalexin, Cefalexina, Céfalexine, Cefalexinum |
| Related Drugs | amoxicillin, prednisone, doxycycline, ciprofloxacin, metronidazole, azithromycin, clindamycin, ceftriaxone, levofloxacin, Augmentin |
| Weight | 125mg/5ml, 100mg/ml, 250mg, 250mg/5ml, 500mg, , 25mg/ml, 50mg/ml, 750mg |
| Type | Dry Syrup, Kid Tablet, Capsule, Suspension, Drops, Powder For Oral Suspension, Capsule*, Tablet, Oral Capsule, Oral Powder For Reconstitution, Oral Tablet |
| Formula | C16H17N3O4S |
| Weight | Average: 347.389 Monoisotopic: 347.093976737 |
| Protein binding | Cephalexin is 10-15% bound to serum proteins including serum albumin.[A179053] |
| Groups | Approved, Investigational, Vet approved |
| Therapeutic Class | First generation Cephalosporins |
| Manufacturer | Embiotic Laboratories (p) Ltd, Eli Lilly And Company, Agp (private) Ltd,, Cipla Ltd, Cooper Pharma |
| Available Country | India, Pakistan, Bangladesh, Canada, Saudi Arabia, United States, |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Keflex is used for the treatment of the following infections when caused by susceptible organisms.
- Respiratory tract infections: Acute and chronic bronchitis and infected bronchiectasis.
- Genito-urinary tract infections: Acute and chronic nephritis, cystitis, urethritis and prostatitis, prophylaxis of recurrent urinary tract infections.
- Skin and soft tissue infections: Caused by staphylococci and/or streptococci.
- Ear, Nose and Throat infections: Otitis media, mastoiditis, sinusitis, follicular tonsillitis and pharyngitis.
- Bone infections: Caused by staphylococci and/or P. mirabilis.
Keflex is also used to associated treatment for these conditions: Bone Infection, Genitourinary tract infection, Otitis Media (OM), Respiratory Tract Infections (RTI), Skin and skin structure infections, Acute Prostatitis
How Keflex works
Keflex is a first generation cephalosporin antibiotic. Cephalosporins contain a beta lactam and dihydrothiazide. Unlike penicillins, cephalosprins are more resistant to the action of beta lactamase. Keflex inhibits bacterial cell wall synthesis, leading breakdown and eventualy cell death.
Dosage
Keflex dosage
Adult:
- The usual dose is 250 mg to 500 mg every 6 hour.
- For skin and soft tissue infections, streptococcal pharyngitis and uncomplicated cystitis, in patients over 15 years of age: 500 mg of the drug may be administered every 12 hour.
- In severe or deep seated infections the dose can be increased up to 3 g to 6 g daily.
Children: The dosage range is 25-100 mg/kg/day in divided doses to a maximum of 4 g dailyChildren's Weight Recommended Dose:
- 10 kg (22 Ibs):62.5 mg to 125 mg qid or 125 mg to 250 mg bid
- 20 kg (44 Ibs):125 mg to 250 mg qid or 250 mg to 500 mg bid
- 40 kg (88 Ibs):250 mg to 500 mg qid or 500 mg to 1 g bid
For streptococcal pharyngitis, skin and soft tissue infections and in patients over 1 year of age the total daily dose may be divided and administered every 12 hour. In the therapy of otitis media 75-100 mg/kg/day in four divided doses may be required. In the treatment of β haemolytic streptococcal infections a therapeutic dosage of the drug should be given at least for 10 days.
Side Effects
Side effects include nausea, vomiting, diarrhoea and abdominal discomfort. Symptoms of pseudomembranous colitis may appear either during or after antibiotic treatment. Skin rash, angio oedema, rise in serum aminotransferases, eosinophilia, neutropenia have been reported very rarely. Superinfection with resistant micro organisms, particularly candida may follow the treatment.
Toxicity
Symptoms of overdose include blood in the urine, diarrhea, nausea, upper abdominal pain, and vomiting. An overdose is generally managed through supportive treatment as diuresis, dialysis, hemodialysis, and charcoal hemoperfusion are not well studied in this case.
The oral median lethal dose of cephalexin in rats is >5000 mg/kg. The oral LD50 in a monkey is >1g/kg and the lowest dose causing a toxic effect in humans is 14mg/kg.
Keflex has not been shown to be harmful in pregnancy and is not associated with teratogeniticy. Keflex is present in breast milk, though infants may be exposed to Label The effects of breast milk exposure to cephalexin have not been established and so caution must be exercised and the risk and benefit of cephalexin use in breastfeeding must be weighed.
Keflex has not been studied for carcinogenicity or mutagenicity. Keflex has no affect on fertility in rats.
Precaution
Cefalexin should be given with caution in patients with renal impairment. Under such condition, careful clinical observation should be made because safe dosage may be lower than the usually recommended. The urine of patients receiving Cefalexin may give a false positive reaction for glucose with copper reduction reagent. Positive results to Coombs’ test have been reported. Although there is no evidence of teratogenicity in animal tests, Cefalexin may be used during pregnancy when it is considered essential. Cefalexin is found in the milk of nursing mothers, hence caution should be taken when it is administered to nursing mothers.
Food Interaction
- Take with or without food.
Keflex multivitamins interaction
[Moderate] ADJUST DOSING INTERVAL: Oral products containing zinc such as mineral supplements and multivitamins may interfere with the gastrointestinal absorption of cephalexin, ceftibuten or cephradine.
In one pharmacokinetic study (n=12), concurrent administration of zinc sulfate (250 mg, single oral dose) and cephalexin (500 mg, single oral dose) decreased cephalexin maximum concentration (Cmax) and systemic exposure (AUC; 0-inf) by 31.05% and 27.4%, respectively.
However, in the same study, when zinc sulfate was administered 3 hours after the cephalexin dose, no significant alteration in cephalexin pharmacokinetics were observed.
Oral medications or mineral supplements that contain zinc are recommended to be administered at least 3 hours after the cephalexin, ceftibuten or cephradine dose.
Keflex Drug Interaction
Unknown: aspirin, aspirin, diphenhydramine, diphenhydramine, omega-3 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, pregabalin, pregabalin, acetaminophen / hydrocodone, acetaminophen / hydrocodone, acetaminophen, acetaminophen, cyanocobalamin, cyanocobalamin, ascorbic acid, ascorbic acid, cholecalciferol, cholecalciferol, cetirizine, cetirizine
Keflex Disease Interaction
Major: colitisModerate: renal dysfunction, dialysis, liver disease, seizure disorders
Volume of Distribution
5.2-5.8L.
Elimination Route
Well absorbed from the upper gastrointestinal tract with nearly 100% oral bioavailability. Keflex is not absorbed in the stomach but is absorbed in the upper intestine.
Patients taking 250mg of cephalexin reach a maximum plasma concentration of 7.7mcg/mL and patients taking 500mg reach 12.3mcg/mL.
Half Life
The half life of cephalexin is 49.5 minutes in a fasted state and 76.5 minutes with food though these times were not significantly different in the study.
Clearance
Clearance from one subject was 376mL/min.
Elimination Route
Keflex is over 90% excreted in the urine after 6 hours by glomerular filtration and tubular secretion with a mean urinary recovery of 99.3%. Keflex is unchanged in the urine.
Pregnancy & Breastfeeding use
Pregnancy Category B. Cefalexin may be used during pregnancy when it is considered essential. Cefalexin is found in the milk of nursing mothers, hence caution should be taken when it is administered to nursing mothers.
Contraindication
Cephalen is contraindicated in patients with known hypersensitivity to the cephalosporin group of antibiotics.
Storage Condition
Should be stored in cool and dry place.
Innovators Monograph
You find simplified version here Keflex
Keflex contains Cephalexin see full prescribing information from innovator Keflex Monograph, Keflex MSDS, Keflex FDA label
FAQ
What Keflex is used for?
Keflex is used to treat bacterial infections in many different parts of the body. It belongs to the class of medicines known as cephalosporin antibiotics. It works by killing bacteria or preventing their growth. However, this medicine will not work for colds, flu, or other virus infections.
How safe is Keflex?
Keflex is not suitable for some people. To make sure Keflex is safe for you, tell your doctor if you have an allergic reaction to Keflex or any other medicine in the past.
How does Keflex work?
Keflex works by interfering with the formation of the bacteria's cell walls. This ruptures the walls and kills the bacteria.Keflex should only be used to treat bacterial infections. You should not use it to treat viruses, such as the common cold.
Is Keflex safe during pregnancy?
Keflex usually safe to take Keflex during pregnancy and while breastfeeding.
Is Keflex safe during breastfeeding?
Keflex is acceptable for nursing mothers.
Can I drink alcohol with Keflex?
You can drink alcohol while taking Keflex. It's important to keep taking Keflex until you've completed the course, even if you feel better.
Can I drive while taking Keflex?
Keflex generally does not cause any problems with your ability to drive a car or operate machinery.
Does Keflex make me sleepy?
Keflex oral capsule doesn't cause drowsiness. However, it can cause other side effects.
When is the best time to take Keflex?
Keflex is usually taken with or without food every 6 or 12 hours for 7 to 14 days, depending on the condition being treated. Take Keflex at around the same times every day.
How long does Keflex take to work?
Peak concentrations of Keflex are reached one hour after dosing; however, it may take up to 48 hours before infection-related symptoms start to abate.
Should Keflex be taken with food?
Although it may be absorbed more quickly if it is taken on an empty stomach, Keflex may be taken with food or on an empty stomach. The overall effect is not changed by taking it with food.
Who should not take Keflex?
You should not use this medicine if you are allergic to Keflex or to similar antibiotics, such as Ceftin, Cefzil, Omnicef, and others. Tell your doctor if you are allergic to any drugs, especially penicillins or other antibiotics.
What happens if I miss a dose of Keflex?
Take Keflex as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What happens if I overdose of Keflex?
Seek emergency medical attention .Overdose symptoms may include nausea, vomiting, stomach pain, diarrhea, and blood in your urine.
Can I take Keflex for a long time?
Continue to take Keflex until you finish the prescription even if you feel better. If you stop taking Keflex too soon or skip doses, your infection may not be completely treated and the bacteria may become resistant to antibiotics.
How long does it take for antibiotics to leave my body?
Each antibiotic may stay in the body for different lengths of time, but common antibiotics such as amoxicillin and Keflex stay in your system for about 24 hours after taking the last dose. It might take longer for people with impaired kidney function to eliminate the drug from the body.
