NORASH CREAM

Indications

• Mild skin irritations
• Insect bites
• Sunburn
• Rashes
• Prickly heat

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines based on age and condition.

Adults: Apply to the affected area as needed, usually 2 to 4 times daily.

Mechanism of action

Calamine exerts its effects mainly through the astringent properties of zinc oxide and the soothing effects of ferric oxide. It helps to dry out oozing and weeping skin, while also providing a cooling sensation to alleviate discomfort.

Pharmacodynamics

The pharmacodynamics of calamine involve its ability to act as a protective barrier on the skin, reducing irritation and discomfort associated with various skin conditions. The astringent properties help to reduce moisture and inflammation, making it effective for soothing skin irritations.

Pharmacokinetics

Calamine is applied topically and is not significantly absorbed into systemic circulation, which minimizes systemic side effects. Its local effects are immediate upon application, providing rapid relief from symptoms like itching and inflammation.

Pregnancy

Calamine is generally considered safe for use during pregnancy, as it is a topical agent with limited systemic absorption.

Breast-feeding

Calamine is also considered safe for use during breastfeeding, as it is unlikely to pose a risk to the nursing infant.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Calamine lotion
• Calamine cream

Indications

• Topical antiseptic for wound care
• Disinfection of skin and mucous membranes
• Cleaning and preparation of the skin prior to surgery
• Management of minor cuts, abrasions, and burns

Dosage

Children: Refer to specific product guidelines for concentration and application frequency, as doses may vary based on formulation.

Adults: Refer to specific product guidelines for concentration and application frequency, as doses may vary based on formulation.

Mechanism of action

Cetrimide works by disrupting the cell membrane of microorganisms, leading to cell lysis and death. It is a surfactant that decreases surface tension and facilitates the penetration of the antiseptic into the microbial cell wall, ultimately causing cell disruption. This mechanism contributes to its broad-spectrum antimicrobial efficacy.

Pharmacodynamics

Cetrimide exhibits bactericidal and fungicidal activity. It is particularly effective against Gram-positive bacteria, with variable activity against Gram-negative organisms. Its surfactant properties enhance its ability to cleanse and disinfect wounds, reducing the risk of infection. Cetrimide's effectiveness is influenced by concentration, contact time, and the presence of organic matter.

Pharmacokinetics

When applied topically, cetrimide is minimally absorbed into systemic circulation, resulting in localized action at the site of application. Its distribution is primarily limited to the skin and mucous membranes. The metabolism and excretion pathways of cetrimide are not well characterized due to its low systemic absorption; however, it is predominantly eliminated through topical use without significant systemic effects.

Adverse effects

• Skin irritation
• Allergic reactions
• Contact dermatitis
• Systemic toxicity if absorbed in large amounts

Precautions

• Avoid contact with eyes
• Use with caution in individuals with sensitive skin
• Not for internal use

Pregnancy

Cetrimide should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus, as there are limited studies on its safety in pregnant women.

Breast-feeding

Cetrimide is not known to be harmful when used topically during breastfeeding; however, it is advisable to avoid application on the breast area to prevent accidental ingestion by the infant.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Topical solution
• Cream
• Ointment
• Wipes

Indications

• Dry skin
• Skin irritation
• Eczema
• Dermatitis
• Cosmetic applications as a moisturizer and thickening agent

Dosage

Children: Refer to specific product guidelines as dosing can vary based on formulation and intended use.

Adults: Refer to specific product guidelines as dosing can vary based on formulation and intended use.

Mechanism of action

Dimethicone works by forming a protective layer on the skin, which helps to seal in moisture and protect the skin from irritants. Its anti-foaming properties are due to its ability to reduce surface tension, allowing gas bubbles to coalesce and escape more easily, thus diminishing the formation of foam in solutions.

Pharmacodynamics

Dimethicone exhibits emollient properties, which means it can soften and soothe the skin. It acts by creating a barrier that prevents transepidermal water loss, thereby enhancing hydration. Its non-irritating nature makes it suitable for sensitive skin, and it does not clog pores, making it a preferred choice in many dermatological preparations.

Pharmacokinetics

Dimethicone is not absorbed systemically; it remains on the skin surface and does not penetrate into the deeper layers of the skin. This characteristic makes it effective as a topical agent. Because it is not metabolized or excreted by the body, its pharmacokinetic profile is primarily focused on its local effects rather than systemic absorption.

Adverse effects

• Allergic reactions
• Skin irritation
• Gastrointestinal discomfort

Precautions

• Use with caution in patients with a history of allergic reactions to silicone-based compounds
• Monitor for any signs of adverse reactions during treatment

Pregnancy

Dimethicone is generally considered safe for use during pregnancy, as it is not absorbed systemically.

Breast-feeding

Dimethicone is considered safe for use during breastfeeding, as it is not absorbed and is unlikely to affect breastfed infants.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Topical creams
• Lotions
• Ointments
• Oral suspensions

Mechanism of action

Oxides do not have a single mechanism of action as they are a broad category of compounds. However, in general, metal oxides can exhibit catalytic properties, while non-metal oxides may participate in biochemical reactions by forming acids or bases upon dissolution in water.

Pharmacodynamics

The pharmacodynamics of oxides depend on the specific type of oxide and its interaction with biological systems. For instance, metal oxides may have antimicrobial properties, while certain non-metal oxides can influence metabolic pathways through their acid-base chemistry. The effects vary widely, necessitating specific studies for each oxide's role in therapeutic contexts.

Pharmacokinetics

The pharmacokinetics of oxides are also variable. Many metal oxides are poorly soluble and thus have limited absorption when ingested. Non-metal oxides, such as carbon dioxide, can be readily absorbed and utilized in metabolic processes. The distribution, metabolism, and excretion of oxides depend on their chemical form and the biological system in which they are involved.

Pregnancy

Not applicable as oxide is not a drug but a class of chemical compounds.

Breast-feeding

Not applicable as oxide is not a drug but a class of chemical compounds.

Storage

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