Benzox 2.5

Indications

• Acne vulgaris
• Comedonal acne
• Inflammatory acne

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations, as pediatric dosing may vary based on age and severity of condition.

Adults: Apply a thin layer to the affected area once or twice daily, gradually increasing frequency as tolerated. Start with once daily application and may increase to twice daily after a week if skin irritation is manageable.

Mechanism of action

The peroxide bond of benzoyl peroxide is cleaved to form two benzoyloxy radicals. These radicals nonspecifically interact with bacterial proteins, disrupting their function and survival. This leads to a reduction in keratin and sebum accumulation around hair follicles. Additionally, benzoyl peroxide enhances the turnover rate of epithelial cells, facilitating skin peeling and helping to break down comedones.

Pharmacodynamics

Benzoyl peroxide acts as a topical agent that generates free radicals to effectively break down comedones and promote epithelial cell turnover. Its action is short-lived, as the active free radical metabolites quickly react to form inactive compounds. The therapeutic index is wide, with rare occurrences of overdose, although skin irritation, dryness, and increased susceptibility to sunburn are common side effects.

Pharmacokinetics

Benzoyl peroxide is applied topically, leading to localized effects with minimal systemic absorption. Its rapid conversion into inactive metabolites limits its duration of action. The compound is metabolized in the skin, and its peak effects are typically observed shortly after application. Due to its formulation and route of administration, the pharmacokinetic profile is characterized by a localized action with reduced risk of systemic side effects.

Adverse effects

• Skin irritation
• Dryness
• Sunburn
• Peeling of skin

Precautions

• Avoid contact with eyes and mucous membranes
• Use with caution in patients with sensitive skin

Pregnancy

Benzoyl peroxide is generally considered safe for use during pregnancy, but it is advisable to consult a healthcare professional before use.

Breast-feeding

Benzoyl peroxide is excreted in breast milk in small amounts. Consult a healthcare professional before use while breastfeeding.

Storage

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

Formulations

• Topical gel
• Topical cream
• Topical lotion

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

Acne vulgaris is caused by inflammation in the pilosebaceous gland. Acne is generally caused by increased excretion of sebum from pilosebaceous glands, endocrine factors such as androgenic hormones, keratin developing around follicles, bacterial growth, and inflammation. These factors contribute to the formation of comedones (whiteheads and blackheads). The peroxide bond of benzoyl peroxide is cleaved to form 2 benzoyloxy radicals. These radicals interact nonspecifically with bacterial proteins, interfering with their function, and survival of the bacteria. Over time, free radical interactions with bacterial proteins lead to decreased keratin and sebum around follicles. Benzoyl peroxide can also increase the turnover rate of epithelial cells, leading to skin peeling, and breaking down comedones.

Pharmacodynamics

Benzoyl peroxide is a topical treatment for acne that generates free radicals to break down comedones and increase the rate of epithelial cell turnover. It has a short duration of action as its active free radical metabolites quickly react to form inactive metabolites. The therapeutic index is wide, as overdoses are rare, however patients may still experience skin peeling. Patients should be counselled regarding increased risks of skin irritation, dryness, and sunburn.

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.