Halobetasol Cream

Mechanism of Action

Although additional studies regarding the mechanism of action of topical corticosteroids are still necessary, topical corticosteroids, including halobetasol cream, generally have the same mechanism of action to exert their anti-inflammatory, immunosuppressive and anti-mitogenic effects. Corticosteroids alter the behavior of epidermal cells, dermal cells, and leukocytes that take part in skin diseases that are proliferative and inflammatory.[3]

Corticosteroids bind to glucocorticoid receptor proteins in the cytoplasm of a cell to form a steroid-receptor complex. In the unbound state, the receptor is cytoplasmic, but in the bound state, the complex moves into the cell nucleus and binds to DNA, changing mRNA transcription. Through this modification, corticosteroids can either increase or decrease the synthesis of proteins involved in the inflammation cascade and the immune response. Corticosteroids increase the synthesis of lipocortin, which acts to reduce the activity of phospholipase A2, which releases arachidonic acid from phospholipids and thus decreases the synthesis of prostaglandins. Corticosteroids also suppress mRNA responsible for interleukin-1 formation. Together, these actions produce anti-inflammatory, immunosuppressive, and anti-mitogenic effects.[3][4]

Administration

Halobetasol cream is administered topically to the skin. As a cream, it is not occlusive like ointments, making it useful in intertriginous areas where ointments are inappropriate. Creams also vanish into the skin easily, making them cosmetically appealing to patients.[1] However, halobetasol propionate comes in a variety of different vehicles, including foams, lotions, and ointments. Foams are the least occlusive and spread rapidly, particularly in hairy areas, but they are generally expensive, whereas the occlusive nature of ointments makes them better suited for thicker, hairless skin.[1]

The standard dosing of halobetasol cream is once to twice daily for two weeks.[5] The patient can calculate the amount of steroid that they should administer to an area through the use of the fingertip unit method. A fingertip unit is represented by the amount that will cover from the tip of the finger to the finger's first crease. For example, one hand-sized area of skin calls for 0.5 fingertip units, which are equivalent to 0.25 grams of medication.[1]

Halobetasol is most commonly available in 0.05% ointment and cream, although as mentioned above, foams and other dose forms are also available. Dosing for steroid-responsive dermatoses is once or twice daily for up to two weeks, with a maximum dosage of 50 g per week. Pateints should be instructed not to apply the drug to their faces, axillae, or groins. 

Adverse Effects

Common adverse effects of halobetasol cream include striae, purpura, rosacea, and acne, with the most common adverse effect being atrophy.[6][1] Less common effects include hypertrichosis, alteration in pigmentation, delayed wound healing, and exacerbation of skin infections.[6] The application of very potent steroids can also induce deep-tissue tinea (fungal) infection known as a Majocchi granuloma.[1]

Systemic adverse effects are also possible, although they are far less prevalent than local adverse effects.[6] Possible systemic effects include hyperglycemia, adrenal insufficiency, Cushing syndrome, suppression of the hypothalamic-pituitary-adrenal axis, and even glaucoma if applied close to the eyes.[6] Children are at increased risk of systemic adverse effects due to their larger skin surface area relative to body weight. Systemic adverse effects usually result from misuse, such as applying topical corticosteroids to extensive areas, especially under occlusion or for a prolonged period.[7]

Contraindications

The treatment of primary bacterial infections, such as impetigo, furuncles, carbuncles, ecthyma, and cellulitis by topical corticosteroids, is an absolute contraindication. The steroid may mask the infection and make it much more difficult to accurately diagnose and treat.[8] Relative contraindications for topical steroids use include candida and dermatophytes. Topical steroids may be used as secondary treatments to decrease inflammation and pruritis in these conditions when appropriate.[8]

Monitoring

Halobetasol cream is typically used once or twice daily for two weeks in patients with plaque psoriasis.[9][5] As an ultra-high potency steroid, patients should not use halobetasol cream for more than three weeks continuously.[1] The drug's high potency makes it more likely to precipitate adverse effects to occur with prolonged use, including, but not limited to, atrophy, striae, bruising, hypertrichosis, Cushing syndrome, and suppression of the hypothalamic-pituitary-adrenal axis. Patients should not use ultra-high-potency steroids like halobetasol cream on the face, groin, axilla, or under occlusion, as these areas have thinner skin, and the intertriginous regions are more likely to develop such adverse effects.[1] Patients should be monitored at follow-up visits every two to three weeks to reassess the condition being treated and modify the use of the corticosteroid cream, if necessary.[10]

Enhancing Healthcare Team Outcomes

Topical corticosteroids, including halobetasol cream, are commonly prescribed by dermatologists for the treatment and management of many inflammatory and pruritic conditions of the skin. They provide rapid relief to patients for a plethora of conditions, and therefore, prescriptions for these agents are very common. However, proper counseling by the physician and pharmacist is not always adequately provided to the patient. Misuse of steroids can lead to clinically serious systemic and/or local effects.[10]

It is crucial to give patients the correct dosage form when prescribing topical corticosteroids. Solutions, foams, gels, lotions, creams, and ointments all have appropriate clinical applications. The proper frequency, amount, and duration of treatment should also be emphasized to patients to avoid overtreating an area, leading to adverse effects, or undertreating an area, leading to poor therapeutic outcomes.[10] Intertriginous regions should not have treatment with ointments, for example, and very rarely should a topical steroid be applied to a particular area more than twice a day.[6]

Additionally, glucocorticoid potency is an essential pharmacologic factor to take into account. Sometimes it is better to prescribe a more potent steroid to provide rapid control of the disease and stop treatment quickly, rather than use a less potent steroid for an extended period, especially in cases of self-limited conditions such as acute irritant dermatitis, panderous dermatitis, etc.[10] However, in other situations, using a less potent formulation (such as halobetasol 0.01% lotion) can offer the same results as a more potent formulation (halobetasol 0.05% cream), in which case the less potent option should be the choice to decrease the possibility of overtreatment and adverse drug effects.[11] Generally, the least potent steroid should be used for the shortest time while still maintaining therapeutic effectiveness.[1]

Additionally, patients may have concerns about prescribed topical steroids that lead to nonadherence due to fear of harming themselves. This factor leads to a significant proportion of patients that do not receive adequate treatment. Therefore, patient education is also important to dispel fears and false notions and ensure the safe use of topical corticosteroids.[6] Nursing and pharmacy can both offer patient counsel on proper administration and alert the patient of specific signs of toxicity to watch for so they can inform their prescriber promptly. The pharmacist should also check for potential interactions, verify that dosing is appropriate, and notify the prescriber of any concerns. These are but a few examples of interprofessional teamwork that can improve patient outcomes and minimize adverse events.

Therapy with halobetasol requires an interprofessional team approach, including physicians, specialty-trained nurses, and pharmacists, collaborating across disciplines to achieve optimal patient outcomes. [Level 5]