Koact oral suspension

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

• Infections caused by beta-lactamase-producing bacteria
• Acute bacterial sinusitis
• Acute otitis media
• Lower respiratory tract infections
• Urinary tract infections

Dosage

Children: Refer to the BNF for Children for specific dosing according to age and weight; adjustments may be necessary based on the clinical scenario.

Adults: Refer to specific product guidelines for dosing; typical regimens depend on the combination antibiotic used and the severity of the infection.

Mechanism of action

Clavulanic acid works by irreversibly binding to the active site of beta-lactamase enzymes that are produced by certain bacteria to inactivate beta-lactam antibiotics. By inhibiting these enzymes, clavulanic acid protects the penicillin antibiotic from degradation, allowing it to exert its antibacterial effects.

Pharmacodynamics

Clavulanic acid has a synergistic effect when combined with other antibiotics, particularly amoxicillin. The presence of clavulanic acid allows for the effective treatment of infections caused by bacteria that would otherwise be resistant to penicillins. Its antibacterial activity is generally weak on its own but significantly enhances the efficacy of other beta-lactam antibiotics.

Pharmacokinetics

Clavulanic acid is rapidly absorbed after oral administration, with peak plasma concentrations occurring within 1 hour. It is widely distributed throughout the body and has a half-life of approximately 1 hour. The drug is primarily excreted unchanged in the urine. In the presence of renal impairment, dosage adjustment may be necessary, as the elimination of clavulanic acid can be affected.

Contra-indications

• Hypersensitivity to clavulanic acid or any of the excipients
• History of jaundice or hepatic impairment associated with previous use of penicillins or beta-lactam antibiotics

Adverse effects

• Nausea
• Diarrhea
• Rash
• Elevated liver enzymes
• Allergic reactions including anaphylaxis
• Superinfection

Interactions

• May enhance the effects of anticoagulants such as warfarin
• Probenecid may increase plasma concentrations of clavulanic acid
• May reduce the efficacy of oral contraceptives

Precautions

• Caution in patients with renal impairment
• Monitor liver function in patients receiving prolonged therapy
• Use with caution in patients with a history of allergic reactions to beta-lactams

Pregnancy

Clavulanic acid is categorized as pregnancy category B. Animal studies have not shown any harm to the fetus, but there are no adequate and well-controlled studies in pregnant women.

Breast-feeding

Clavulanic acid is excreted in breast milk, but it is generally considered safe for use during breastfeeding. Monitor for potential effects in the infant.

Storage

Store at room temperature, away from moisture and heat. Protect from light. Keep out of reach of children.

Formulations

• Oral tablets
• Oral suspension
• Injectable forms

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.