CLINDAMYCIN BENZOYL PEROXIDE SOAP

Indications

• Bacterial infections
• Skin and soft tissue infections
• Respiratory tract infections
• Bone and joint infections
• Dental infections
• Acne vulgaris (topical use)
• Intra-abdominal infections

Dosage

Adults: Refer to BNF for specific dosing recommendations based on the type and severity of the infection. Dosage may vary

Mechanism of action

Clindamycin inhibits bacterial protein synthesis by binding to the 23S RNA of the 50S subunit of the bacterial ribosome. This binding impedes both the assembly of the ribosome and the translation process. Clindamycin acts as a structural analog of tRNA molecules, impairing peptide chain initiation and stimulating the dissociation of peptidyl-tRNA from bacterial ribosomes. Its action may be bacteriostatic or bactericidal, depending on the concentration achieved at the infection site and the susceptibility of the pathogen.

Pharmacodynamics

Clindamycin exerts its bacteriostatic effect through the inhibition of microbial protein synthesis. It has a relatively short time to maximum concentration (Tmax) and half-life, necessitating frequent dosing to maintain adequate antibiotic levels. Clindamycin is associated with the risk of Clostridium difficile-associated diarrhea (CDAD), which can range from mild diarrhea to severe colitis. This side effect is due to the disruption of normal gut flora and the overgrowth of C. difficile, leading to toxin production.

Pharmacokinetics

Clindamycin is well absorbed when taken orally, with a bioavailability of approximately 90%. It distributes widely in body tissues and fluids, including bone. The drug undergoes hepatic metabolism, primarily via cytochrome P450 enzymes, and is excreted in urine as both unchanged drug and metabolites. The elimination half-life is approximately 2 to 3 hours, and renal impairment may affect its clearance.

Contra-indications

• Hypersensitivity to clindamycin or lincomycin
• History of antibiotic-associated colitis
• Use in patients with significant gastrointestinal disorders

Adverse effects

• Diarrhea
• Nausea
• Vomiting
• Rash
• Abdominal pain
• Clostridium difficile-associated diarrhea (CDAD)
• Hepatotoxicity
• Allergic reactions

Interactions

• Clindamycin may enhance the effects of neuromuscular blocking drugs
• Clindamycin may interact with other antibiotics leading to altered susceptibility patterns

Precautions

• Use with caution in patients with renal impairment
• Monitor for signs of colitis
• Assess liver function prior to therapy
• Avoid use in patients with a history of significant gastrointestinal disease

Pregnancy

Clindamycin is classified as category B. Animal studies have not demonstrated a risk to the fetus, but there are no adequate and well-controlled studies in pregnant women.

Breast-feeding

Clindamycin is excreted in breast milk, but significant absorption by the infant is unlikely. Caution is advised.

Storage

Store in a cool, dry place away from light. Reconstituted solutions should be stored in accordance with manufacturer guidelines and used within the specified time frame.

Formulations

• Oral capsules
• Oral suspension
• Solution for injection
• Topical solution and gel

Indications

• Bacterial infections
• Pneumonia
• Meningitis
• Syphilis
• Endocarditis
• Skin and soft tissue infections

Dosage

Children: Paediatric dosing for benzylpenicillin is determined by the child's weight and the severity of the infection. Refer to the BNF for Children for specific dosing guidelines.

Adults: The usual adult dose for benzylpenicillin varies based on the type and severity of the infection. It is generally administered via intramuscular or intravenous routes. For severe infections, doses may range from 1 to 4 million units every 4 to 6 hours.

Mechanism of action

Benzylpenicillin exerts its antibacterial effects by inhibiting the synthesis of bacterial cell walls. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, disrupting the transpeptidation process, which is crucial for cross-linking peptidoglycan layers. This inhibition leads to cell lysis and death of the bacteria.

Pharmacodynamics

Benzylpenicillin demonstrates time-dependent bactericidal activity, meaning its effectiveness is related to the duration of time the drug concentration remains above the minimum inhibitory concentration (MIC) for the target bacteria. It has a narrow spectrum of activity, primarily targeting Gram-positive cocci and some Gram-negative rods.

Pharmacokinetics

Benzylpenicillin is typically administered parenterally due to poor oral absorption. It is rapidly distributed throughout the body and can penetrate various tissues, including the central nervous system during inflammation. The drug is primarily eliminated by renal excretion, with a half-life of approximately 30 minutes to 1 hour in healthy individuals. Dosage adjustments may be necessary in patients with renal impairment.

Interactions

• leflunomide+benzylpenicillin: Unknown (increases exposure)
• nitisinone+benzylpenicillin: Unknown (increases exposure)
• teriflunomide+benzylpenicillin: Unknown (increases exposure)

Pregnancy

Benzylpenicillin is generally considered safe to use during pregnancy, as it is a penicillin antibiotic and has a long history of use.

Breast-feeding

Benzylpenicillin is excreted in breast milk in small amounts, but it is not expected to have adverse effects on a nursing infant.

Storage

Store in a cool, dry place, protected from light. Reconstituted solutions should be used promptly or stored in a refrigerator and used within a limited time frame.

Formulations

• Benzylpenicillin injection

Indications

• Topical antiseptic for minor cuts and abrasions
• Wound cleansing
• Deodorizing agent

Dosage

Children: For paediatric use, hydrogen peroxide can be applied topically as a 3% solution. Consult the BNF for Children for detailed dosing guidance.

Adults: Hydrogen peroxide is typically applied topically as a 3% solution. It can be used to cleanse the affected area one to three times daily. For specific dosing, refer to the BNF.

Mechanism of action

The production of free hydroxyl radicals in the Fenton reaction is thought to be the basis of the biocidal actions of hydrogen peroxide. Free radicals lead to oxidative damage to proteins and membrane lipids in vivo. The release of nascent oxygen upon contact with catalase-containing tissues exerts antibacterial action, while effervescence mechanically loosens tissue debris and pus. Hydrogen peroxide is particularly effective on wounds, denuded areas, and mucous membranes.

Pharmacodynamics

Hydrogen peroxide exhibits antimicrobial properties against a wide range of microorganisms, including resistant forms such as bacterial spores and protozoal cysts. It acts as an oxidative biocide, generating free radicals that induce damage to DNA, proteins, and membrane lipids via oxidation. Its mechanical action of effervescence assists in the removal of tissue debris, which is a crucial aspect of its effectiveness in wound management.

Pharmacokinetics

Hydrogen peroxide's pharmacokinetics are not extensively detailed in the literature, but it is known to have poor tissue and wound penetration. The presence of reactive organic materials, such as pus and blood, diminishes its efficacy. The mechanical action of effervescence is significant in enhancing its antibacterial effects, particularly in contaminated wounds.

Adverse effects

• Skin irritation
• Burning sensation
• Allergic reactions

Precautions

• Avoid contact with eyes and mucous membranes
• Use with caution in patients with a history of hypersensitivity
• Do not apply to deep or puncture wounds

Pregnancy

Hydrogen peroxide should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult a healthcare provider before use.

Breast-feeding

Caution is advised when using hydrogen peroxide while breastfeeding. Consult a healthcare provider for guidance.

Storage

Store in a cool, dry place away from light and out of reach of children. Keep in tightly closed containers.

Formulations

• Topical solution
• Ointment

Mechanism of action

Clindamycin inhibits bacterial protein synthesis by binding to 23S RNA of the 50S subunit of the bacterial ribosome. It impedes both the assembly of the ribosome and the translation process. The molecular mechanism through which this occurs is thought to be due to clindamycin's three-dimensional structure, which closely resembles the 3'-ends of L-Pro-Met-tRNA and deacylated-tRNA during the peptide elongation cycle - in acting as a structural analog of these tRNA molecules, clindamycin impairs peptide chain initiation and may stimulate dissociation of peptidyl-tRNA from bacterial ribosomes. The mechanism through which topical clindamycin treats acne vulgaris is unclear, but may be related to its activity against _Propionibacterium acnes_, a bacteria that has been associated with acne. Clindamycin may be bacteriostatic or bactericidal in action, depending on the concentration of the drug attained at the site of infection and the susceptibility of the infecting organism. Clindamycin palmitate hydrochloride and clindamycin phosphate are inactive until hydrolyzed to free clindamycin. This hydrolysis occurs rapidly in vivo. Clindamycin appears to inhibit protein synthesis in susceptible organisms by binding to 50S ribosomal subunits; the primary effect is inhibition of peptide bond formation. The site of action appears to be the same as that of erythromycin, chloramphenicol, and lincomycin. Clindamycin binds exclusively to the 50S subunit of bacterial ribosomes and suppresses protein synthesis. ... Clindamycin is not a substrate for macrolide efflux pumps, and strains that are resistant to macrolides by this mechanism are susceptible to clindamycin.

Pharmacodynamics

Clindamycin exerts its bacteriostatic effect via inhibition of microbial protein synthesis. Clindamycin has a relatively short T_max and half-life necessitating administration every six hours to ensure adequate antibiotic concentrations. _Clostridium difficile_ associated diarrhea (CDAD) has been observed in patients using clindamycin, ranging in severity from mild diarrhea to fatal colitis and occasionally occurring over two months following cessation of antibiotic therapy. Overgrowth of _C. difficile_ resulting from antibiotic use, along with its production of A and B toxins, contributes to morbidity and mortality in these patients. Because of the associated risks, clindamycin should be reserved for serious infections for which the use of less toxic antimicrobial agents are inappropriate. Clindamycin is active against a number of gram-positive aerobic bacteria, as well as both gram-positive and gram-negative anaerobes. Resistance to clindamycin may develop, and is generally the result of base modification within the 23S ribosomal RNA. Cross-resistance between clindamycin and lincomycin is complete, and may also occur between clindamycin and macrolide antibiotics (e.g. [erythromycin]) due to similarities in their binding sites. As antimicrobial susceptibility patterns are geographically distinct, local antibiograms should be consulted to ensure adequate coverage of relevant pathogens prior to use.

Mechanism of action

The production of free hydroxyl radicals in the Fenton reaction is thought to be the basis of biocidal actions of hydrogen peroxide. Free radicals eventually lead to oxidative damage proteins and membrane lipids _in vivo_. The oxidizing radical as the ferryl radical induces DNA oxidation. Hydrogen peroxide topical solution is a weak antibacterial agent, a wound cleanser, and a deodorant. The pharmacologic activity of the drug depends on the release of nascent oxygen which has a powerful oxidizing effect that destroys some microorganisms and chemically alters many organic substances. When hydrogen peroxide topical solution comes in contact with tissues that contain the enzyme catalase, the solution releases oxygen which exerts antibacterial action; the mechanical effect of effervescence loosens tissue debris and pus. The release of nascent oxygen and effervescence is more rapid on wounds, denuded areas, and mucous membranes than on unbroken skin. The presence of reactive organic material such as pus and blood diminishes the efficiency of hydrogen peroxide. The antibacterial activity of hydrogen peroxide is relatively weak and slow and the drug exhibits poor tissue and wound penetration. Hydrogen peroxide's mechanical effect of effervescence and resultant removal of tissue debris is probably a more effective means of reducing the bacterial content of wounds, denuded areas, and mucous membranes than actual antibacterial activity. The drug also appears to have a styptic effect when applied topically to minor wounds. Concentrated solutions of hydrogen peroxide have a bleaching effect on hair and may injure tissue. Increases in the levels of reactive oxygen species (ROS) are correlated with a decrease in calcineurin (CN) activity under oxidative or neuropathological conditions. However, the molecular mechanism underlying this ROS-mediated CN inactivation remains unclear. Here, we describe a mechanism for the inactivation of CN by hydrogen peroxide. The treatment of mouse primary cortical neuron cells with Abeta(1-42) peptide and hydrogen peroxide triggered the proteolytic cleavage of CN and decreased its enzymatic activity. In addition, hydrogen peroxide was found to cleave CN in different types of cells. Calcium influx was not involved in CN inactivation during hydrogen peroxide-mediated cleavage, but CN cleavage was partially blocked by chloroquine, indicating that an unidentified lysosomal protease is probably involved in its hydrogen peroxide-mediated cleavage. Treatment with hydrogen peroxide triggered CN cleavage at a specific sequence within its catalytic domain, and the cleaved form of CN had no enzymatic ability to dephosphorylate nuclear factor in activated T cells. Thus, our findings suggest a molecular mechanism by which hydrogen peroxide inactivates CN by proteolysis in ROS-related diseases. Matrix metalloproteinase-2 (MMP-2) is well known to proteolyse both extracellular and intracellular proteins. Reactive oxygen species activate MMP-2 at both transcriptional and post-translational levels, thus MMP-2 activation is considered an early event in oxidative stress injury. Although hydrogen peroxide is widely used to trigger oxidative stress-induced cell death, the type of cell death (apoptosis vs. necrosis) in cardiomyocytes is still controversial depending on the concentration used and the exposure time. We ... investigated the mode of cell death in neonatal rat cardiomyocytes induced by different concentrations (50-500 uM) of hydrogen peroxide at various time intervals after exposure and determined whether MMP-2 is implicated in hydrogen peroxide-induced cardiomyocyte death. Treating cardiomyocytes with hydrogen peroxide led to elevated MMP-2 level/activity with maximal effects seen at 200 uM. Hydrogen peroxide caused necrotic cell death by disrupting the plasmalemma as evidenced by the release of lactate dehydrogenase in a concentration- and time-dependent manner as well as the necrotic cleavage of PARP-1. The absence o

Pharmacodynamics

Hydrogen peroxide exhibits antimicrobial properties against most forms of microorganisms, including dormant forms with known high resistance profiles, such as bacterial spores and protozoal cysts. It acts as an oxidative biocide to generate free radical species to induce DNA, protein and membrane lipid damage via oxidation.