21/01/2026
# # # 💊 A Meeting with Mr. Cephalexin 💊
👨🏻⚕️: What is your name?
💊: My name is Cephalexin. I am a first-generation cephalosporin antibiotic.
👨🏻⚕️: What is your work?
💊: I am a Bactericidal Antibiotic. My job is to kill susceptible bacteria causing infections by disrupting the synthesis of their cell wall, causing them to burst and die.
👨🏻⚕️: Tell me about yourself.
💊: I am a semi-synthetic antibiotic derived from the *Cephalosporium* fungus. I am known primarily for my effectiveness against Gram-positive bacteria and some Gram-negative bacteria. I am stable in stomach acid, which allows me to be taken orally.
👨🏻⚕️: What is your mechanism of action?
💊: I bind to specific penicillin-binding proteins (PBPs) inside the bacterial cell wall. This binding inhibits the final step of peptidoglycan synthesis. The weakened, incomplete wall cannot withstand the cell's internal osmotic pressure, leading to cell lysis and death.
👨🏻⚕️: What about your metabolism?
💊: I am not significantly metabolized by the liver. Over 90% of me is excreted unchanged in the urine via glomerular filtration and tubular secretion in the kidneys.
👨🏻⚕️: What about your elimination?
💊: My elimination is rapid and primarily renal. I have a short half-life, ranging from 0.5 to 1.2 hours, which is why I need to be dosed multiple times a day (usually every 6 to 12 hours). My dose must be adjusted in patients with significant kidney impairment.
👨🏻⚕️: How are you administered?
💊: My administration is straightforward.
🔻 My primary and preferred route is Oral (by mouth). I am available as capsules, tablets, and an oral suspension for children.
🔻 I am not available for intravenous (IV) or intramuscular (IM) administration. Other cephalosporins are used for those routes.
🔻 I can be taken with or without food, although food may help minimize stomach upset.
🔻 My dose is measured in milligrams (mg) and is based on the type and severity of the infection, as well as the patient's
