Topical Medication Flashcards
What are the main types of bases used in topical treatments?
The main types of bases include ointments, creams, lotions, solutions, gels, pastes, foams, and solids. Each type has different compositions and uses depending on the condition being treated.
What is the role of emulsifiers in topical formulations?
Emulsifiers reduce surface tension between oil and water phases, allowing them to mix into a stable emulsion. However, they can cause irritation or contact allergy.
How is the dosage of topical treatments determined?
Dosage is often measured in fingertip units (FTUs), where one FTU is about 0.5 grams. Specific areas of the body require different amounts (e.g., 3 grams for a leg).
What are ointments primarily composed of?
Ointments are primarily composed of grease or oil and are either water-free or nearly water-free (less than 20% water). Common ingredients include hydrocarbons like paraffin, wool fat, and vegetable oils.
What are the benefits of using ointments?
Ointments form an impermeable layer over the skin, reducing transepidermal water loss, increasing barrier function, softening dry skin, easing itching, and allowing active ingredients to penetrate the skin
What types of skin conditions are ointments most suitable for?
Ointments are suitable for dry skin, eczema, and conditions requiring moisture retention and prevention from frostbite.
What are the disadvantages of using ointments?
Disadvantages include being sticky, difficult to apply on hairy skin, occlusive (which can lead to pomade acne), hard to wash off with water, and potentially trapping bacteria, yeasts, and fungi.
How do non-emulsifying and emulsifying ointments differ?
Non-emulsifying ointments do not penetrate the skin and have only superficial activity. Emulsifying ointments contain some water and can help mix oil and water phases, improving the delivery of active ingredient
What are some common emulsifiers used in ointments?
Common emulsifiers include lanette wax, cetomacrogol wax, beeswax, cetostearyl alcohol, and sodium lauryl sulfate, which help mix oil and water phases in emulsifying ointments.
In what situations might ointments increase the risk of sunburn?
Ointments can increase the risk of sunburn by acting like a magnifier, reflecting and concentrating sunlight on the skin.
How can ointments aid in preventing frostbite?
Ointments can aid in preventing frostbite by forming a protective barrier that retains heat and moisture, protecting the skin from extreme cold.
Why might ointments not be suitable for wet or exudative skin conditions?
Ointments are not suitable for wet or exudative conditions because they are occlusive and do not mix well with skin exudates, potentially worsening the condition.
What are creams composed of?
Creams consist of lipophilic (fat-loving) and hydrophilic (water-loving) phases combined with one or more emulsifiers and preservatives. They have a water content that allows them to rub into the skin easily.
What are the two main types of creams, and how do they differ?
The two main types are oil-in-water (O/W) creams and water-in-oil (W/O) creams. O/W creams have an aqueous outer phase, are washable, and are cosmetically acceptable, while W/O creams have a fatty outer phase and better drug absorption.
What are the advantages of using creams?
Advantages of creams include easy application, cosmetic friendliness, being less or non-occlusive, and serving as a good base for many active ingredients.
What are some disadvantages of using creams?
Disadvantages include the need for preservatives and emulsifiers, potential skin drying, higher cost compared to ointments, and stability problems.
In what situations are oil-in-water creams most suitable?
Oil-in-water creams are suitable for normal or slightly oily skin and for conditions like eczema that are a bit oozing. They leave a thin layer of oil on the skin as the water evaporates, which may be too drying for very dry skin
When are water-in-oil creams preferred?
Water-in-oil creams are preferred for dry skin conditions because they enhance the absorption of active ingredients and are more stable in warm conditions. However, they are less suitable for wet dermatitis and tropical climates due to stability issues.
How do creams differ in their application to different areas of the body?
Creams are preferred in areas like skin folds and flexural areas due to their non-occlusive nature, which reduces the risk of irritation and maceration that can occur with ointments.
Why do creams require preservatives?
Creams require preservatives to prevent microbial growth, as their water content makes them vulnerable to contamination.
What role do emulsifiers play in creams?
Emulsifiers help combine the oil and water phases in creams, creating a stable emulsion that allows the cream to be spread easily and absorbed into the skin.
How can the stability of creams be enhanced?
Stability can be enhanced by adding humectants like glycerol or sorbitol to prevent water evaporation, especially in stored creams. This helps maintain the cream’s consistency and effectiveness over time.
What are lotions?
Lotions are low-viscosity topical preparations consisting of a mixture of oil and water, typically with an emulsifier. They are thinner than creams and ointments, making them easy to spread over large areas.
What are the two main types of lotions?
The two main types of lotions are shake lotions and diluted creams. Shake lotions are powder in a water phase, offering a cooling and drying effect. Diluted creams are emulsions made by adding water to a cream.
What are the benefits of using lotions?
Benefits include ease of application, especially on hairy areas, scalps, and large body surfaces. Lotions are also cosmetically acceptable and quick to absorb into the skin.
What is a common use for shake lotions?
Shake lotions are used for their cooling (anti-itch) effect. After evaporation, the inert powder is left on the skin, which can help soothe itchy conditions
Why are lotions suitable for hairy skin and flexural areas?
Lotions are suitable for these areas because they are less viscous and can be spread easily without leaving a greasy residue, unlike creams or ointments.
What are the limitations of using lotions?
Limitations include a potential for drying out the skin due to their water content and the need for preservatives to prevent microbial growth. They may also be less effective in providing occlusion or moisture retention.
How are lotions used for drying skin conditions?
Lotions are often used for drying skin conditions because their evaporation can help reduce moisture, making them suitable for conditions with excessive exudate or sweating.
How do lotions differ from creams and ointments in terms of water content?
Lotions have a higher water content than creams and ointments, making them lighter and less greasy. This makes them ideal for covering large areas quickly
What are the common uses for solutions in dermatology?
Solutions are often used for their drying effects and are applied to areas where moisture needs to be controlled. They can also be used to deliver medications to specific areas of the skin.
What are the advantages of using solutions?
Advantages include rapid evaporation, which provides a cooling and drying effect. Solutions are easy to apply and are well-suited for treating large or hairy areas.
Why are solutions effective for certain skin infections?
Solutions can help dry out infected areas, reducing moisture that bacteria or fungi thrive in, making them effective for conditions like athlete’s foot or fungal infections.
What are some common active ingredients found in solutions?
Common active ingredients include antiseptics like gentian violet or potassium permanganate, which are used for their antimicrobial properties.
What are pastes in dermatology?
Pastes are topical formulations that combine oil, water, and a high concentration of powder (up to 50%), resulting in a thick, adhesive consistency that stays in place on the skin.
What are the main benefits of using pastes?
Benefits include their ability to absorb exudate from the skin, prevent the spread of active ingredients to surrounding areas, and provide a protective barrier that remains in place even as the skin warms
In what situations are pastes most suitable?
Pastes are ideal for treating moist or oozing skin conditions, as their high powder content helps to absorb moisture and keep the affected area dry.
What are some common applications of pastes?
Pastes are used for conditions like diaper rash, bedsores, and chronic wounds where moisture absorption and prolonged contact with active ingredients are beneficial.
How do pastes differ from ointments and creams?
Pastes have a higher powder content, making them thicker and more adhesive than ointments and creams, which allows them to stay put and not spread easily.
What are some examples of pastes used in dermatology?
Examples include zinc oxide pastes for diaper rash and coal tar pastes for psoriasis, where the paste serves as a vehicle for the active ingredient.
What are gels in dermatology?
Gels are semi-solid topical preparations consisting of a liquid phase (usually water) thickened with a gelling agent, resulting in a clear or translucent, non-greasy product that liquefies upon skin contact.
What are gels commonly used for?
Gels are commonly used for acne treatments, as they allow for quick delivery of active ingredients like benzoyl peroxide or retinoids without leaving a residue.
How do gels differ from creams and ointments?
Gels are less occlusive and contain more water than creams and ointments, which makes them lighter, less greasy, and better suited for oily skin types
What role do gelling agents play in gels?
Gelling agents, such as carbomers or cellulose derivatives, thicken the liquid phase to form a semi-solid gel, providing structure and stability while allowing the gel to liquefy on contact with the skin
Why are gels preferred for hairy areas?
Gels are preferred for hairy areas like the scalp because they spread easily without clumping in the hair, providing effective delivery of active ingredients to the skin.
What are some common active ingredients found in gels?
Common active ingredients include benzoyl peroxide, retinoids, antibiotics, and antifungals, which are used for their targeted effects on acne, infections, and other skin conditions.
How do gels provide a cooling effect?
Gels provide a cooling effect as the water content evaporates from the skin, offering relief from itching and inflammation, which can be beneficial for conditions like sunburn or dermatitis.
What factors should be considered when selecting a base for topical treatment?
Key factors include the nature of the skin condition (dry, wet, or inflamed), the area of the body (hairy, non-hairy, skin folds), and the desired effect (hydrating, drying, protective).
What type of base is suitable for wet or oozing skin conditions?
For wet or oozing skin conditions, oil-in-water (O/W) creams, lotions, and drying pastes are most suitable as they help absorb excess moisture and reduce exudate.
What base is recommended for dry, scaly skin conditions?
For dry, scaly skin conditions, ointments and oils are appropriate as they provide a strong hydrating effect and form a protective barrier to prevent moisture loss.
What base is preferred for inflamed skin?
For inflamed skin, wet compresses followed by creams or ointments can help soothe irritation and provide a barrier to protect the skin
Why are lotions or gels recommended for hairy areas?
Lotions and gels are recommended for hairy areas because they spread easily and are non-greasy, preventing matting and ensuring the active ingredients reach the skin.
What is a Fingertip Unit (FTU) in topical prescription?
An FTU is a measurement of topical medication, equal to approximately 0.5 grams, enough to cover an area of skin equivalent to two adult palms.
How much topical medication is generally needed for the whole body for one application?
For one full-body application, 20-30 grams of topical medication is typically required.
How much cream or ointment is needed for the face and neck?
Approximately 1 gram of cream or ointment is needed for the face and neck for one application
How much topical medication is required for a single leg?
About 3 grams, or 6 FTUs, is needed for one leg.
How much should be prescribed for a single hand?
About 0.5 grams, or 1 FTU, is sufficient for one hand.
What are the three main routes for skin entry of topical medications?
The three main routes are intercellular (between cells), intracellular (through cells), and transappendageal (via hair follicles and sweat glands).
Why are neonates at higher risk of systemic toxicity from topical medications?
Neonates have a higher surface area-to-body weight ratio, suboptimal epidermal barrier function, decreased hepatic metabolism, and more permeable blood-brain barriers, increasing the risk of systemic toxicity.
What are the primary effects of corticosteroids in dermatology?
Corticosteroids suppress inflammation, reduce cell proliferation, and cause vasoconstriction, making them effective for treating various inflammatory skin conditions.
How are topical corticosteroids classified?
Topical corticosteroids are classified by potency into four categories: weak (e.g., hydrocortisone acetate 1%), moderate (e.g., triamcinolone acetonide 0.1%), strong (e.g., betamethasone 17 valerate 0.1%), and potent (e.g., clobetasol 17 propionate 0.05%).
What are some local side effects of topical corticosteroids?
Local side effects can include skin atrophy, striae (stretch marks), bruising, hypertrichosis (excess hair growth), suppression of pigmentation, telangiectasia (dilated blood vessels), perioral dermatitis, and acne.
What are some systemic side effects of topical corticosteroids?
Systemic side effects may include Cushing’s syndrome, reduced stress response, central obesity, muscle weakness, high blood pressure, depression, anxiety, and growth retardation in children.
What are the uses and limitations of gentian violet as an antiseptic?
Gentian violet is used against streptococci, staphylococci, and Candida infections. It can stain permanently and is suspected to be a carcinogen at high concentrations.
What is an advantage of silver nitrate as an antiseptic?
Silver nitrate is non-sensitizing and well-tolerated with a narrow therapeutic window. It is used for treating burns and leg ulcers but can stain skin and clothes.
What is the role of sulfur in antiseptic treatments?
Sulfur has keratolytic, antiseborrheic, and antimicrobial effects, making it useful for conditions like acne, seborrheic dermatitis, and scabies.
What is a common use for neomycin in topical treatments, and what is a downside?
Neomycin is used for its antibacterial properties but has a relatively small spectrum and hypersensitivity is not uncommon. It is often combined with other antibiotics
Why is bacitracin often combined with neomycin in topical formulations?
Bacitracin is generally well-tolerated and enhances the antibacterial spectrum when combined with neomycin, but it is unstable in water and should be used in water-free preparations
What are the applications of erythromycin and clindamycin in topical treatments?
Erythromycin and clindamycin are used for acne, folliculitis, and bacterial vaginosis, but they are unstable in water, necessitating careful formulation and storage
How is fusidic acid used in topical antibiotics, and what are its limitations?
Fusidic acid is effective against resistant staphylococci but is less active in the presence of blood and pus and is unstable in water.
What is mupirocin used for in topical antibiotic treatments?
Mupirocin is used to treat infections caused by resistant staphylococci, offering a targeted approach for difficult-to-treat bacterial strains.
Why is tetracycline used as a topical antibiotic, and what are its limitations?
Tetracycline is used for its immunomodulatory properties and is well-tolerated. However, it is unstable in water, can cause photosensitivity, and should not be used after week 16 of pregnancy
What are the benefits and risks associated with chloramphenicol as a topical antibiotic?
Chloramphenicol is moderately sensitizing but reasonably stable. A serious risk is bone marrow depression, which can occur with its use.
What is Whitfield’s ointment, and what are its components?
Whitfield’s ointment is a traditional antifungal preparation containing salicylic acid (3%) for its keratolytic properties and benzoic acid (6%) for antifungal activity against dermatophytes.
What are imidazoles, and what is their spectrum of activity?
Imidazoles are broad-spectrum antifungals effective against dermatophytes, Candida species, and some bacteria like Corynebacteria. They are known for being quick and non-toxic.
What is a notable characteristic of gentian violet as an antifungal?
Gentian violet is used for Candida infections and some bacterial infections, offering a low-cost treatment option, but it can stain the skin and is suspected to be carcinogenic in high concentrations.
What is nystatin used for, and what is a limitation of its use?
Nystatin is specifically used for treating Candida infections but is extremely unstable and has developed much resistance, limiting its effectiveness.
How is sodium thiosulfate used in antifungal treatments?
Sodium thiosulfate (25%) is used for conditions like pityriasis versicolor. It is well-tolerated, non-toxic, and very cheap, making it a practical option for treatment.
What is the treatment regimen for permethrin as an antifungal?
Permethrin 5% cream is used twice, one week apart, and should be applied for 8-12 hours before washing off. It is effective for scabies, especially in babies and the elderly.
Why might benzyl benzoate emulsion be less favored as an antifungal treatment?
Benzyl benzoate is less effective than other options like lindane and is more expensive than permethrin. Its toxicity is not as well-documented, leading to caution in use.
What is a common side effect of antifungal treatments that must be managed?
Antifungal treatments can often cause skin irritation or allergic reactions, requiring careful monitoring and potential adjustment of treatment.
Why is it important to continue antifungal treatment after symptoms resolve?
Continuing treatment for a few days after symptoms resolve ensures that the infection is completely eradicated and reduces the risk of recurrence.
How is permethrin 5% cream used in scabies treatment?
Permethrin 5% cream is applied once, left on the skin for 8-12 hours, and then washed off. The application is repeated one week later to ensure all mites are eradicated.
What are some potential side effects of using scabicides like permethrin and benzyl benzoate?
Potential side effects include skin irritation, itching, and redness. These symptoms should be monitored, and the treatment should be adjusted if necessary.
What is the role of salicylic acid in keratolytic treatments?
Salicylic acid, in concentrations of 2-50%, acts as a keratoplastic at lower concentrations and as a keratolytic at higher concentrations. It enhances the penetration of corticosteroids and has mild antiseptic activity.
How does benzoyl peroxide function as a keratolytic?
Benzoyl peroxide (5-10%) acts as a keratolytic, drying agent, and bacteriostatic, making it effective in treating acne. However, it can bleach skin, hair, and clothing and may cause irritation and sensitization.
What is the use of retinoic acid in keratolytic treatments?
Retinoic acid (0.05%-1%) accelerates the formation and shedding of the horny layer, has anti-inflammatory properties, and is used for acne. It is irritative, unstable, and should not be used during pregnancy.
What are the properties of tar in keratolytic treatments?
Tar is keratoplastic, antiseptic, antipruritic, and anti-inflammatory. It is used for eczema and psoriasis, is cheap, but can cause temporary skin discoloration and is difficult to handle during production.
How is resorcinol used as a keratolytic?
Resorcinol (2-15%) is used for its keratolytic properties, particularly in conditions like hidradenitis suppurativa. It may cause systemic side effects and irritation at higher concentrations.
What is the function of urea in keratolytic formulations?
Urea (5-10%) is a strong moisturizer and keratolytic. It is useful for dry, hyperkeratotic skin diseases and enhances the penetration of corticosteroids and other drugs but may cause burning on damaged skin.
How does capsaicin work as an antipruritic?
Capsaicin (0.025% or 0.075%) works by desensitizing nociceptors, which reduces the sensation of itch and pain. It is used for conditions like neuropathic itch and pain.
What is the function of menthol and camphor in antipruritic formulations?
Menthol and camphor (2%) provide a cooling sensation that helps change the perception of itch. They are often used in low concentrations for temporary itch relief.
Why should menthol and camphor not be used in small children?
In small children, menthol and camphor can cause laryngospasm, a serious condition where the vocal cords spasm and block air flow to the lungs
How does phenol work as an antipruritic?
Phenol, in concentrations of 0.5% to 1%, acts as a local anesthetic to numb the skin and provide itch relief. At higher concentrations, it has antiseptic and caustic properties.
What is the primary use of dithranol in dermatology?
Dithranol is primarily used as a topical treatment for psoriasis, where it helps to reduce excessive skin cell growth and inflammation
How does dithranol work as an anti-psoriatic agent?
Dithranol works by binding to DNA and inhibiting mitosis, leading to an antiproliferative effect on keratinocytes and reducing psoriasis plaqu
What is the method of application for dithranol known as “short contact therapy”
Short contact therapy involves applying dithranol to the affected area for 10-30 minutes daily, then washing it off. This method reduces the risk of skin irritation.
What is the mechanism of action of Vitamin D analogs in psoriasis treatment?
Vitamin D analogs normalize keratinocyte differentiation, decrease cell proliferation, and exhibit anti-inflammatory effects, helping to manage psoriasis symptoms.
What is a common Vitamin D analog used in topical treatments?
Calcipotriol (also known as calcipotriene) is a common Vitamin D analog used in topical treatments for psoriasis
