Cephalexin: How Is It Used?

Disclaimer.  I am not a licensed health practitioner.  This is just another post on knowledge and understanding you might wish to acquire in advance of a disaster in case no higher care is available.  As long as our society is functioning, you should leave anything more substantial than applying a Band-Aid to the professionals.  No medication, including those available over the counter, should be taken without consulting a physician.  Information shared here is for educational and entertainment purposes only.  It is not medical advice nor a substitute for licensed medical care. 

Cephalexin, another antibiotic commonly stocked by preparedness-minded individuals, is the most familiar member of the cephalosporin family of antibiotics.   Marketed by the brand name Keflex, this antibiotic is effective against most Gram-positive and Gram-negative bacteria.  It disrupts cell wall formation, eventually rupturing the wall, causing all the innards to leak out and the bacteria to die. It's a weapon you want in your war against bad bacteria.


Cephalexin is a relatively inexpensive antibiotic.  If you can't get it through your family physician, overseas pharmacies are an option.  Barring that, the veterinary equivalent can be purchased at some feed and ranch stores, often under the names Fish-Flex (250 mg) and Fish-Flex Forte (500 mg). The most common dosing regimen is taking the capsules every six hours for seven to fourteen days, less for bladder infections, and much longer for bone infections.  Pediatric dosages range from 12.5 to 25 milligrams per kilogram of body weight.

When treating various bacterial infections with cephalexin, physicians will prescribe along the lines of the following:

• upper respiratory infections:
• pneumonia, bronchitis, 250 mg, four times per day OR 500 mg, twice per day, 7-14 days
• strep throat, 250 mg, four times per day OR 500 mg, twice per day, 7-14 days
• ear infection
• adults, 250 mg, four times per day OR 500 mg, twice per day, 7-14 days
• children 12.5-25 mg/kg/day, in two divided doses, for 7-14 days 
• skin:
• impetigo, 250 mg, four times per day, 7-14 days
• cellulitis, 500 mg, four times per day, 7-14 days
• mastitis, 500 mg, four times per day, 10-14 days
• urogenital:
• cystitis, 250 mg, four times per day OR 500 mg, twice per day, 7 days, but may discontinue two days after symptoms pass
• pyelonephritis, 250 mg, four times per day OR 500 mg, twice per day, 7 days
• prostatitis,  250 mg, four times per day OR 500 mg, twice per day, 7 days
• osteomyelitis, 500 mg, two to four times per day, 4-6 weeks

Cephalexin may be taken with or without food.  However, individuals with sensitive stomachs should take it with food and a full glass of water.

Links to related posts:
Allergic to Penicillin?  What Are the Options? 
Alternative Medicine--Usnea
Amoxicillin
Penicillin 

For further reading:  

Dr. Cynthia Koelker, Armageddon Medicine 
Dr. Joseph Alton, Alton's Antibiotics, p 157 
Survival and Austere Medicine, 3rd Edition, p 210 

20 feb 2022