Zoraxin 800 mg Tablet

Potential Overview:

Generic Name :Cephalexin

Brand Name :Zoraxin

Pack Size :10 tablets per pack (800 mg each)

Mechanism of Action (MOA):

• Cephalexin, the active ingredient in Zoraxin, is a first-generation cephalosporin antibiotic. It works by inhibiting bacterial cell wall synthesis, leading to bacterial cell lysis and death. This action is primarily against Gram-positive bacteria and some Gram-negative organisms.

Indications:

Zoraxin (Cephalexin) is typically used for:

• Bacterial Infections: It treats a variety of infections caused by susceptible organisms, such as:
  • Respiratory tract infections (e.g., pneumonia, bronchitis)
  • Urinary tract infections (UTIs)
  • Skin and soft tissue infections
  • Otitis media (middle ear infections)
  • Bone infections
  • Genital infections

Dosage:

• The dosage varies based on the type of infection and the patient’s condition.
  • Adults: Typically, 250 mg to 1 g every 6-12 hours, depending on the severity of the infection.
  • Children: Dosage is adjusted based on weight, typically 25-50 mg/kg/day in divided doses.
• Always follow the healthcare provider’s directions for the exact dosage.

Side Effects:

Common side effects of Zoraxin (Cephalexin) include:

• Gastrointestinal disturbances: Nausea, vomiting, diarrhea
• Rashes or allergic reactions (e.g., hives, itching)
• Headache
• Dizziness
• Abdominal pain
• Rare side effects: Clostridium difficile-associated diarrhea, liver enzyme elevations, or kidney issues.

Precautions:

• Allergy: Be cautious in patients with a known allergy to penicillin or other beta-lactam antibiotics, as cross-reactivity can occur.
• Renal Impairment: Dose adjustments may be needed for patients with impaired kidney function.
• Pregnancy and Lactation: Cephalexin is generally considered safe in pregnancy and breastfeeding, but it should still be used under medical supervision.
• Superinfection: Prolonged use can lead to superinfection (secondary infections caused by resistant organisms).

Contraindications (CI):

• Hypersensitivity: Contraindicated in individuals with a history of severe hypersensitivity (allergic reactions) to cephalosporins or other beta-lactam antibiotics.

Pharmacist Related Data

Chemical Name and Formula:

• Chemical Name: (6R,7R)-3-methyl-8-oxo-7-[2-(2-thienyl)-2-oxo-ethoxyimino] -4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid
• Molecular Formula: C16H17N3O4S
• IUPAC Name: (6R,7R)-3-methyl-7-[2-(2-thienyl)-2-oxo-ethoxyimino]-8-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid

Half-Life:

• Half-life: Approximately 1 hour in healthy individuals.
• This may be extended in patients with renal impairment.

Metabolism:

• Cephalexin is not extensively metabolized by the liver. It remains largely unchanged in the body and is excreted via the kidneys.
• It undergoes minimal hepatic metabolism, with most of the drug excreted unchanged in the urine.

Drug Interactions with Food and Medicines:

Drug Interactions:

• Probenecid: Co-administration with probenecid (a drug used to treat gout) may increase the serum concentration of Cephalexin by decreasing renal clearance.
• Other antibiotics: Use with other antibiotics (especially broad-spectrum ones) can lead to antagonistic effects or superinfection due to antibiotic resistance.
• Oral Contraceptives: While there is no strong evidence, some studies suggest antibiotics like Cephalexin may reduce the effectiveness of oral contraceptives, so alternative methods of contraception are recommended during treatment.
• Anticoagulants: Cephalexin may interact with warfarin and other anticoagulants, potentially increasing the risk of bleeding.

Food Interactions:

• Food does not significantly affect the absorption of Cephalexin, so it can be taken with or without food.
• Dairy Products: Some suggest taking Cephalexin with food if stomach upset occurs, and there is no major interaction with dairy products, although it’s always advisable to check with a healthcare provider.

Pharmacodynamics:

• Mechanism of Action:
  Cephalexin is a beta-lactam antibiotic, specifically a first-generation cephalosporin. It works by inhibiting the synthesis of bacterial cell walls, specifically targeting the enzyme penicillin-binding proteins (PBPs). This inhibition leads to the lysis and death of the bacterial cell.
• Spectrum of Activity:
  Cephalexin is primarily effective against Gram-positive bacteria (e.g., Streptococcus, Staphylococcus) and some Gram-negative organisms (e.g., E. coli, Klebsiella). It is commonly used for skin, respiratory, and urinary tract infections.
• Bactericidal Effect:
  As a bactericidal agent, Cephalexin kills bacteria rather than merely inhibiting their growth.

Pharmacokinetics:

1. Absorption:
   • Cephalexin is rapidly absorbed after oral administration.
   • Peak plasma concentrations are reached in 1 to 2 hours after ingestion.
   • It has a bioavailability of around 90%, meaning most of the drug reaches the bloodstream.
2. Distribution:
   • Cephalexin is widely distributed throughout the body, including to the lungs, kidneys, and skin.
   • It has a protein binding rate of 15% to 20%.
   • The drug also crosses the placenta and is excreted in breast milk.
3. Metabolism:
   • Cephalexin is not extensively metabolized by the liver and remains largely unchanged in the body.
   • It undergoes minimal metabolism compared to other antibiotics.
4. Excretion:
   • Cephalexin is primarily excreted unchanged by the kidneys through glomerular filtration and tubular secretion.
   • About 80% of the drug is excreted unchanged in the urine within 6 hours.
   • In patients with renal impairment, the elimination half-life may be prolonged, necessitating dose adjustments.