SORIFIX OINTMENT

Indications

• Severe resistant inflammatory skin disorders
• Eczema unresponsive to less potent corticosteroids
• Psoriasis

Dosage

Children: For children aged 1–17 years: apply 1–2 times a day for up to 4 weeks, to be applied thinly.

Adults: Apply 1–2 times a day for up to 4 weeks, to be applied thinly, with a maximum of 50 g of 0.05% preparation per week between courses of more potent corticosteroids.

Mechanism of action

Clobetasol propionate exerts its effects by binding to the glucocorticoid receptor, leading to decreased vasodilation and capillary permeability, reduced leukocyte migration to inflammation sites, and modulation of gene expression. It inhibits the production of pro-inflammatory mediators and promotes the expression of anti-inflammatory genes, resulting in an overall anti-inflammatory effect. The drug also has immunosuppressive properties at higher doses.

Pharmacodynamics

As a corticosteroid, clobetasol propionate significantly inhibits pro-inflammatory signals while promoting anti-inflammatory responses. Its effects can last for an extended duration when applied twice daily. It has a wide therapeutic window, allowing for doses significantly higher than the body's natural corticosteroid production. However, long-term use can lead to suppression of the hypothalamic-pituitary-adrenal axis and increase the risk of infections.

Pharmacokinetics

Clobetasol propionate is well-absorbed through the skin, with systemic absorption dependent on the formulation and application site. Once absorbed, it is distributed throughout the body and metabolized primarily in the liver. Its elimination half-life varies, but the drug is generally excreted in urine. Due to its potency, careful monitoring is required to avoid systemic side effects, particularly with prolonged use.

Adverse effects

• skin atrophy
• telangiectasia
• striae
• systemic absorption leading to adrenal suppression
• burning sensation at application site
• allergic reactions including contact dermatitis

Precautions

• Use with caution in patients with a history of diabetes or hypertension
• Avoid prolonged use on large surface areas
• Monitor for signs of infection at the application site
• Consider potential systemic effects with high doses or extended use

Pregnancy

Clobetasol propionate should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Topical corticosteroids should be used cautiously.

Breast-feeding

It is not known whether clobetasol propionate is excreted in human milk. Caution should be exercised when administering to nursing women.

Storage

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

Formulations

• 0.05% cream
• 0.05% ointment
• 0.05% foam
• 0.05% scalp application
• 0.05% shampoo

Indications

• Plaque psoriasis
• Mild to moderate plaque psoriasis
• Scalp psoriasis

Dosage

Children: For children aged 6–11 years, apply twice daily, with a maximum total calcipotriol of 2.5 mg in any one week. For children aged 12–17 years, apply twice daily, not exceeding 3.75 mg in any one week.

Adults: Apply calcipotriol ointment or scalp solution to the affected areas twice daily. Maximum total calcipotriol dosage should not exceed 5 mg per week.

Mechanism of action

Calcipotriol binds to vitamin D receptors in skin cells, leading to the regulation of gene expression involved in cell proliferation and differentiation. This action promotes the normal maturation of keratinocytes and reduces hyperproliferation, which is a hallmark of psoriatic lesions. Additionally, it exhibits anti-inflammatory properties, further aiding in the management of psoriasis.

Pharmacodynamics

Calcipotriol has a dose-dependent effect on keratinocyte proliferation and differentiation. It decreases the production of pro-inflammatory cytokines and chemokines, which are elevated in psoriasis. The therapeutic effects are typically observed within a few weeks of treatment, with optimal results often seen after sustained use. Side effects may include local skin irritation and an increased risk of hypercalcemia, especially if used excessively.

Pharmacokinetics

When applied topically, calcipotriol is minimally absorbed through intact skin. Systemic absorption can occur, particularly when applied to large areas or under occlusion. The half-life of calcipotriol is approximately 1.5 hours in systemic circulation, but its effects persist due to its action on skin cells. The drug is metabolized primarily in the liver, with metabolites excreted through urine and feces.

Contra-indications

• Calcium metabolism disorders
• Erythrodermic exfoliative psoriasis
• Generalised pustular psoriasis
• Do not apply under occlusion

Adverse effects

• Skin reactions
• Hypercalcaemia
• Hypercalciuria
• Photosensitivity reactions
• Increased risk of infection

Interactions

• Acitretin

Precautions

• Avoid excessive exposure to sunlight
• Avoid broken or inflamed skin
• Caution in patients with renal impairment
• Caution in patients with hepatic impairment

Pregnancy

Manufacturers advise avoidance unless essential.

Breast-feeding

No information available.

Storage

Store in a cool, dry place away from light.

Formulations

• Calcipotriol 50 micrograms/g ointment
• Calcipotriol scalp solution

Indications

• Severe eczema
• Psoriasis
• Contact dermatitis
• Lichen planus
• Seborrheic dermatitis
• Dermatitis herpetiformis
• Nummular eczema

Dosage

Children: Refer to the BNF for Children for specific dosing guidance, as clobetasol is typically used in children with caution and under medical supervision.

Adults: Apply a thin layer to the affected area once or twice daily, depending on the severity of the condition and the area involved. Treatment should be limited to the shortest duration necessary to control symptoms.

Mechanism of action

Clobetasol propionate has anti-inflammatory, antipruritic, and vasoconstrictive properties. Its anti-inflammatory activity is believed to stem from the induction of phospholipase A2 inhibitory proteins, known as lipocortins. These proteins are thought to regulate the production of inflammatory mediators such as prostaglandins and leukotrienes by inhibiting the release of arachidonic acid, a precursor to these mediators, from membrane phospholipids.

Pharmacodynamics

Clobetasol works by modulating the immune response and inflammatory process in the skin. By limiting the release of pro-inflammatory substances, clobetasol reduces the signs and symptoms of inflammation, such as redness, swelling, and itching. Its vasoconstrictive properties also contribute to its efficacy by reducing blood flow to the affected area, further diminishing inflammation.

Pharmacokinetics

Clobetasol is well-absorbed through the skin, and its absorption can be influenced by the condition of the skin barrier and the vehicle in which it is delivered. It is primarily metabolized in the liver and excreted via the urine. The pharmacokinetic profile of clobetasol indicates a relatively short systemic half-life due to its rapid metabolism, minimizing the risk of systemic side effects when used topically as directed.

Contra-indications

• Hypersensitivity to clobetasol or any of its excipients
• Viral infections (e.g., herpes simplex, chickenpox)
• Bacterial infections
• Fungal infections
• Rosacea
• Acne vulgaris

Adverse effects

• Burning sensation
• Itching
• Skin atrophy
• Telangiectasia
• Striae
• Systemic effects (with prolonged use)

Precautions

• Use with caution in patients with a history of steroid sensitivity
• Long-term use may lead to adrenal suppression
• Monitor for signs of local or systemic infections
• Not recommended for use on the face or in intertriginous areas without medical advice

Pregnancy

Clobetasol should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Limited data available on the use of topical corticosteroids in pregnancy.

Breast-feeding

Caution is advised when using clobetasol during breastfeeding. It is not known if it is excreted in human milk.

Storage

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

Formulations

• Topical cream
• Topical ointment
• Topical lotion

Mechanism of action

The precise mechanism of calcipotriol in remitting psoriasis is not well-understood, however, it has been shown to have comparable affinity with calcitriol for the Vitamin D receptor while being less than 1% the activity in regulating calcium metabolism. The Vitamin D receptor (VDR) belongs to the steroid/thyroid receptor superfamily, and is found on the cells of many different tissues including the thyroid, bone, kindney, and T cells of the immune system. T cells are known to play a role in psoriasis and are believed to undergo modulation of gene expression with binding of calcipotriol to the VDR. This modulation is thought to affect gene products related to cell differentiation and proliferation.

Pharmacodynamics

Calcipotriene is a synthetic analog of vitamin D. In humans, the natural supply of vitamin D depends mainly on exposure to the ultraviolet rays of the sun for conversion of 7-dehydrocholesterol to vitamin D3 (cholecalciferol) in the skin.

Mechanism of action

The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels.

Pharmacodynamics

Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Clobetasol propionate is generally applied twice daily so the duration of action is long. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections.

Mechanism of action

Like other topical corticosteroids, clobetasol propionate has anti-inflammatory, antipruritic, and vasoconstrictive properties. The mechanism of the anti-inflammatory activity of the topical steroids, in general, is unclear. However, corticosteroids are thought to act by the induction of phospholipase A2 inhibitory proteins, collectively called lipocortins. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor, arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A2.