ZETOREN TABLETS

Indications

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

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations tailored to the child's age and weight.

Adults: Refer to the BNF for specific dosing guidelines, as it can vary depending on the type and severity of the infection.

Mechanism of action

The bactericidal activity of cefditoren results from the inhibition of cell wall synthesis via its affinity for penicillin-binding proteins (PBPs). It is stable against various beta-lactamases, including penicillinases and some cephalosporinases.

Pharmacodynamics

Cefditoren pivoxil is a prodrug that is converted to its active form, cefditoren, during absorption through hydrolysis by esterases. The active drug is then distributed in the blood, where it exerts its antibacterial effects against both gram-positive and gram-negative pathogens, including methicillin-susceptible strains of Staphylococcus aureus and various strains of Streptococcus, Haemophilus, and Moraxella species.

Pharmacokinetics

Cefditoren is absorbed after oral administration and is converted to the active form cefditoren. It has a distribution in the bloodstream and exhibits a half-life that allows for convenient dosing. The drug is eliminated predominantly via the kidneys, and its pharmacokinetics can be influenced by renal function.

Pregnancy

There is insufficient data on the use of cefditoren in pregnancy. Use only if clearly needed and the benefits outweigh the risks.

Breast-feeding

Cefditoren is excreted in breast milk; caution should be exercised when administering to nursing mothers.

Storage

Store below 25°C. Protect from light and moisture.

Formulations

• Cefditoren pivoxil 200 mg tablets
• Cefditoren pivoxil 400 mg tablets

Indications

• Herpes simplex virus infections
• Varicella-zoster virus infections
• Other viral infections as indicated by a healthcare professional

Dosage

Children: Refer to the BNF for Children for specific pediatric dosing guidelines, as dosing is typically based on age and weight.

Adults: Refer to the BNF for specific dosing guidelines for adults, as dosing may vary based on the type and severity of the infection.

Mechanism of action

Pivoxil is converted to acyclovir in the body, which then inhibits viral DNA synthesis. Acyclovir specifically targets the viral DNA polymerase enzyme, leading to the termination of viral DNA chain elongation. This action effectively prevents the replication of the virus within host cells.

Pharmacodynamics

The therapeutic effect of pivoxil is largely attributable to its active metabolite, acyclovir, which exhibits selective toxicity for virally infected cells due to its preferential uptake and phosphorylation in these cells. This results in a higher concentration of the active form within infected cells than in uninfected cells, contributing to its effectiveness against herpes viruses.

Pharmacokinetics

Following oral administration, pivoxil is rapidly absorbed and converted to acyclovir, which has a bioavailability of approximately 15-30%. The peak plasma concentration is reached within 1-2 hours. Acyclovir is widely distributed in body tissues and fluids, including the central nervous system. It is primarily eliminated by renal excretion, with a half-life of approximately 2.5 to 3 hours in patients with normal renal function.

Contra-indications

• Hypersensitivity to pivoxil or any component of the formulation
• Severe respiratory depression
• Acute or severe bronchial asthma
• Known or suspected gastrointestinal obstruction

Adverse effects

• Drowsiness
• Dizziness
• Dry mouth
• Constipation
• Nausea
• Vomiting
• Blurred vision
• Urinary retention

Interactions

• CNS depressants (e.g., alcohol, barbiturates, benzodiazepines) may enhance sedative effects
• Anticholinergic agents may increase the risk of urinary retention and constipation

Precautions

• Use with caution in patients with respiratory conditions, such as chronic obstructive pulmonary disease (COPD)
• Caution in elderly patients due to increased sensitivity to the drug
• Monitor for signs of overdose, particularly in patients taking other CNS depressants

Pregnancy

Limited data on the use of pivoxil during pregnancy. Caution is advised, and the drug should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Pivoxil is excreted in breast milk. Caution is advised when administering to nursing mothers, as it may affect the infant.

Storage

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

Formulations

• Tablets
• Syrup

Mechanism of action

The bactericidal activity of cefditoren results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins (PBPs). Cefditoren is stable in the presence of a variety of b-lactamases, including penicillinases and some cephalosporinases.

Pharmacodynamics

Cefditoren pivoxil is a prodrug which is hydrolyzed by esterases during absorption, and the drug is distributed in the circulating blood as active cefditoren. Cefditoren is a cephalosporin with antibacterial activity against gram-positive and gram-negative pathogens. Cefditoren is effective against <i>Staphylococcus aureus</i> (methicillin-susceptible strains, including b-lactamase-producing strains), penicillin-susceptible strains of <i>Staphylococcus aureus</i> and <i>Streptococcus pneumoniae</i>, <i>Streptococcus pyogenes</i>, <i>Haemophilus influenzae</i> (including b-lactamase-producing strains), <i>Haemophilus parainfluenzae</i> (including b-lactamase-producing strains), <i>Moraxella catarrhalis</i> (including b-lactamase-producing strains), <i>Streptococcus agalactiae</i>, <i>Streptococcus</i> Groups C and G, and <i>Streptococcus</i>, viridans group (penicillin-susceptible and -intermediate strains).