Cephalexin - Uses - Dosages - Side Effects - Precautions

Cephalexin: Frequently Asked Questions Answered

What is Cephalexin?

Cephalexin is an antibiotic belonging to the class of first-generation cephalosporins. It is a broad-spectrum beta-lactam antibiotic effective against both gram-positive and gram-negative bacteria. 

The structure of cephalosporins consists of a beta-lactam ring, which inhibits the bacteria from synthesising the peptidoglycan present in the bacterial cell wall, resulting in the loss of cell viability and leading to the autolysis (death) of bacterial cells. However, some bacteria develop resistance by expressing beta-lactamase enzymes and other bacterial defence mechanisms.

What are the uses of Cephalexin?

Cephalexin is indicated for the treatment of acute and chronic urinary tract infections, upper respiratory tract infections, and gonorrhoea (a sexually transmitted bacterial infection). It is also effective against staphylococcal and streptococcal skin infections.

Other uses include the treatment of ear and bone infections and dental infections. It is also used as a prophylactic treatment to prevent infections after surgical procedures.

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What are the side effects of Cephalexin?

Cephalexin has a relatively low incidence of side effects when administered correctly. Common side effects include soreness in the oral cavity, itching of the skin, nausea, vomiting, diarrhoea, and stomach upset. 

Rare side effects include Stevens-Johnson syndrome and toxic epidermal necrolysis (life-threatening serious skin conditions resulting in rashes, blisters, and peeling of the skin). Other less commonly noticed side effects include abdominal pain, clay-colored stool, dark urine, headaches, rashes, and red and irritating eyes. 

Most of the side effects usually subside without requiring medical attention. However, the severe effects of the Stevens-Johnson syndrome and toxic epidermal necrolysis require immediate medical care.


Frequently Asked Questions about Cephalexin

1. Is Cephalexin a good antibiotic?

Yes, Cephalexin is a good antibiotic that acts against a wide variety of organisms and has a relatively low rate of side effects. It is used to treat several conditions, including middle ear, bone, joint, skin, and throat infections. It is a safe medication that should be taken exactly as directed by your doctor.

2. What should I not take with Cephalexin?

Drugs like probenecid, metformin, and furosemide, and mineral supplements containing zinc should not be taken along with Cephalexin.

Co-administration of metformin will lead to decreased renal (kidney) clearance and an increased plasma concentration of metformin, while probenecid decreases the renal clearance of cephalexin. Furosemide when given with cephalexin may increase your risk of kidney damage. Therefore, necessary precautions must be taken to avoid undesired side effects.

In patients with kidney problems, precaution must be taken by analysing the kidney function and creatinine clearance test reports while on treatment with cephalexin.

3. Is Cephalexin penicillin?

No, cephalexin is not penicillin. It is a beta-lactam antibiotic and belongs to the class of cephalosporins. Although penicillin is also a beta-lactam antibiotic, cephalosporins are not penicillin derivatives.

4. Can I take Cephalexin on an empty stomach?

Yes, you can take cephalexin on an empty stomach. In fact, it is advisable to take cephalexin this way as the drug favours an empty stomach, helping it absorb easily. Dairy products can cause decreased absorption of antibiotics.

5. Is Cephalexin used for tooth infections?

Yes, cephalexin can be used for tooth infection as it can act against streptococcus and staphylococcus, the common pathogens for tooth infection. In addition, it is also effective against E. coli and other gram-negative bacteria that cause root canal infections.

6. Can I lie down after taking cephalexin?

After taking the antibiotic, you should avoid lying down since it may increase the time it takes for the medication to pass through your oesophagus and into your stomach, potentially irritating your oesophagus. Hence, it is not advisable to lie down immediately after taking the oral medication.

7. Should I take probiotics with Cephalexin?

Yes, probiotics help protect the useful microorganisms in your gut. It also helps prevent antibiotic-induced diarrhoea. The most appropriate choice is Lactobacillus or Saccharomyces at 5–20 billion colony-forming units per day. However, further studies must be conducted to substantiate the evidence.

8. Is Cephalexin safe for the kidneys?

A substantial amount of cephalexin is eliminated through the kidney. It is not a safe drug for patients with impaired renal function or elderly patients, as it can result in impaired excretion and toxicity.

9. What vitamins should I avoid while taking Cephalexin?

According to the literature, no direct interactions are found between cephalexin and vitamins. However, multivitamins containing zinc must be avoided. Zinc can cause impaired absorption of cephalexin, as it is proven to decrease the bioavailability of this drug. Several studies have reported that zinc can be taken three hours after taking this drug.

10. Can I drink milk while taking Cephalexin?

Although there is no direct interaction between cephalexin and milk, it is advisable not to take antibiotics with milk as it may decrease the amount of medicine absorbed into the bloodstream. You can take dairy products two to three hours before taking an antibiotic.



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      Disclaimer: The information provided herein is accurate, updated and complete as per the best practices of the Company. Please note that this information should not be treated as a replacement for physical medical consultation or advice. We do not guarantee the accuracy and the completeness of the information so provided. The absence of any information and/or warning to any drug shall not be considered and assumed as an implied assurance of the Company. We do not take any responsibility for the consequences arising out of the aforementioned information and strongly recommend you for a physical consultation in case of any queries or doubts.