QUIXINCLAV 652MG TABLETS

Indications

• Bacterial infections
• Urinary tract infections
• Sinusitis
• Uncomplicated community-acquired pneumonia
• Salmonellosis
• Oral infections
• Lyme disease (under expert supervision)
• Acute exacerbation of bronchiectasis
• Anthrax (treatment and post-exposure prophylaxis)

Dosage

Children: 1 month–11 years: 30 mg/kg 3 times a day for 21 days; children 1–4 years: 250 mg 3 times a day; children 5–11 years: 500 mg 3 times a day.

Adults: 500 mg 3 times a day; increased if necessary up to 1 g 3 times a day in severe infections.

Mechanism of action

Amoxicillin works by inhibiting bacterial cell wall synthesis, leading to cell lysis and death. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, interfering with the transpeptidation process necessary for cell wall integrity.

Pharmacodynamics

Amoxicillin exhibits bactericidal activity against susceptible bacteria. Its action is time-dependent, meaning that its effectiveness is related to the duration of time that the drug concentration remains above the minimum inhibitory concentration (MIC) for the target pathogen.

Pharmacokinetics

Amoxicillin is well absorbed from the gastrointestinal tract, with peak plasma concentrations achieved within 1-2 hours after oral administration. It is widely distributed in body tissues and fluids, and it is excreted primarily via the kidneys. The elimination half-life is approximately 1 hour, and renal impairment may necessitate dosage adjustments.

Adverse effects

• Skin rash
• Gastrointestinal disturbances (nausea, vomiting, diarrhea)
• Allergic reactions (including anaphylaxis)
• Superinfection (due to resistant organisms)

Interactions

• Allopurinol (increases risk of skin rash)

Precautions

• History of penicillin allergy
• Renal impairment (reduce dose)
• Use with caution in patients with mononucleosis

Pregnancy

Use only if clearly needed; no adequate studies in pregnant women.

Breast-feeding

Amoxicillin is excreted in breast milk; use with caution.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Phenoxymethylpenicillin 250mg/5ml oral solution
• Phenoxymethylpenicillin 250 mg tablets

Indications

• Bacterial infections
• Respiratory tract infections
• Urinary tract infections
• Skin and soft tissue infections

Dosage

Children: Refer to the BNF for Children for appropriate dosing based on the age and weight of the child.

Adults: Refer to specific guidelines and BNF for appropriate dosing regimens based on the condition being treated.

Mechanism of action

Clavulanate works by irreversibly binding to the active site of beta-lactamase enzymes, which are produced by some bacteria to confer resistance to beta-lactam antibiotics. By inhibiting these enzymes, clavulanate prevents the breakdown of the antibiotic, allowing it to exert its antibacterial effects more effectively. This mechanism enhances the spectrum of activity of the combined antibiotic against resistant bacterial strains.

Pharmacodynamics

The pharmacodynamics of clavulanate involve its role as a beta-lactamase inhibitor, which enhances the activity of penicillins and cephalosporins against beta-lactamase-producing organisms. The presence of clavulanate increases the susceptibility of beta-lactam-resistant bacteria to these antibiotics, thereby improving clinical outcomes in infections caused by such organisms. The combination of clavulanate with other antibiotics allows for broader coverage against a range of pathogens.

Pharmacokinetics

Clavulanate is well absorbed after oral administration, with a bioavailability of approximately 60-70%. It reaches peak plasma concentrations within 1 hour. The drug is widely distributed throughout body tissues and fluids, and it is primarily metabolized in the liver. Clavulanate is excreted mainly in the urine, both as unchanged drug and as metabolites. The elimination half-life of clavulanate is approximately 1 hour, necessitating frequent dosing for optimal therapeutic effect.

Contra-indications

• Hypersensitivity to clavulanate or any component of the formulation
• History of severe allergic reactions to beta-lactams

Adverse effects

• Diarrhea
• Nausea
• Vomiting
• Rash
• Allergic reactions including anaphylaxis
• Hepatotoxicity
• Candidiasis

Interactions

• Probenecid may increase serum concentrations of clavulanate
• Antibiotics may alter gut flora, potentially affecting the efficacy of oral contraceptives

Precautions

• Use with caution in patients with liver dysfunction
• Monitor for signs of allergic reactions during therapy
• Caution in patients with a history of gastrointestinal disease, particularly colitis

Pregnancy

Clavulanate should only be used during pregnancy if clearly needed. Animal studies have not shown teratogenic effects, but limited data is available in humans.

Breast-feeding

Clavulanate is excreted in breast milk. Caution is advised when administering to nursing mothers, as effects on the infant are unknown.

Storage

Store in a cool, dry place away from light. Keep out of reach of children. Do not use after the expiration date.

Formulations

• Tablets
• Oral suspension
• Injectable formulations

Mechanism of action

Amoxicillin competitively inhibits penicillin-binding protein 1 and other high molecular weight penicillin binding proteins. Penicillin bind proteins are responsible for glycosyltransferase and transpeptidase reactions that lead to cross-linking of D-alanine and D-aspartic acid in bacterial cell walls. Without the action of penicillin binding proteins, bacteria upregulate autolytic enzymes and are unable to build and repair the cell wall, leading to bacteriocidal action. The penicillins and their metabolites are potent immunogens because of their ability to combine with proteins and act as haptens for acute antibody-mediated reactions. The most frequent (about 95 percent) or "major" determinant of penicillin allergy is the penicilloyl determinant produced by opening the beta-lactam ring of the penicillin. This allows linkage of the penicillin to protein at the amide group. "Minor" determinants (less frequent) are the other metabolites formed, including native penicillin and penicilloic acids. /Penicillins/ Amoxicillin is similar to penicillin in its bactericidal action against susceptible bacteria during the stage of active multiplication. It acts through the inhibition of cell wall biosynthesis that leads to the death of the bacteria.

Pharmacodynamics

Amoxicillin competitively inhibit penicillin binding proteins, leading to upregulation of autolytic enzymes and inhibition of cell wall synthesis. Amoxicillin has a long duration of action as it is usually given twice daily. Amoxicillin has a wide therapeutic range as mild overdoses are not associated with significant toxicity. Patients should be counselled regarding the risk of anaphylaxis, _Clostridium difficile_ infections, and bacterial resistance.