Safety and Efficacy of Fluticasone Propionate in the Topical Treatment of Skin Diseases
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View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Open Access LMU Review Skikin Pharmacoollogy Skin Pharmacol Physiol 2005;18:3–11 Received: May 10, 2004 Accepted after revision: July 22, 2004 and DOI: 10.1159/000081680 Physioliology Safety and Efficacy of Fluticasone Propionate in the Topical Treatment of Skin Diseases A. Roedera M. Schallerb M. Schäfer-Korting c H.C. Korting a aKlinik und Poliklinik für Dermatologie und Allergologie, Ludwig-Maximilians-Universität, München, bUniversitäts-Hautklinik, Klinikum der Universität Tübingen, Tübingen, und cInstitut für Pharmazie, Pharmakologie und Toxikologie, Freie Universität Berlin, Berlin, Deutschland Key Words Introduction Fluticasone propionate W Topical corticosteroids W Atopic dermatitis W Psoriasis W Vitiligo Topical glucocorticoids are the drugs most often pre- scribed by dermatologists due to their anti-inflammatory, immunosuppressive and antiproliferative effects, which Abstract are thought to be their primary mechanism of action in Fluticasone propionate – the first carbothioate corticoste- the treatment of several skin disorders [1]. The clinical roid – has been classified as a potent anti-inflammatory use of these drugs, however, is still restricted by the poten- drug for dermatological use. It is available as 0.05% tial for adverse events. Therefore recent research has cream and 0.005% ointment formulations for the acute focused on the development of steroids with lower toxici- and maintenance treatment of patients with dermatolog- ty without a loss of effectiveness. The synthetic carbo- ical disorders such as atopic dermatitis, psoriasis and thioate corticosteroid fluticasone propionate (FP, Fluti- vitiligo. This glucocorticoid is characterized by high lipo- vate®) combines excellent clinical efficacy with minimal philicity, high glucocorticoid receptor binding and activa- risk for local or systemic adverse events. It is available as a tion, and a rapid metabolic turnover in skin. Although cream and ointment with similar potency, yet differing skin blanching following fluticasone propionate exceeds strength (0.05 vs. 0.005%) of the active agent. This article that of corticosteroids of medium strength, several clini- reviews the pharmacology and the safety profile as well as cal trials demonstrate a low potential for cutaneous and the use of topical FP in clinical practice, paying particular systemic side-effects, even in difficult-to-treat areas like attention to the treatment and prophylaxis of skin dis- the face, the eyelids and intertriginous areas. Even eases such as atopic dermatitis (AD), psoriasis and among paediatric patients with atopic dermatitis, flutica- vitiligo. sone propionate proved to be safe and effective. These pharmacological and clinical properties are reflected by the high therapeutic index of this glucocorticoid. Copyright © 2005 S. Karger AG, Basel © 2005 S. Karger AG, Basel Alexander Roeder ABC 1660–5527/05/0181–0003$22.00/0 Ludwig-Maximilians-Universität München Fax + 41 61 306 12 34 Klinik und Poliklinik für Dermatologie und Allergologie E-Mail [email protected] Accessible online at: Frauenlobstrasse 9–11, DE–80337 Munich (Germany), Tel.+49 89 5160 6151 www.karger.com www.karger.com/spp Fax+49 89 5160 6132, E-Mail [email protected] Fig. 1. Molecular structure of cortisol, FP and its inactive metabolite. Structural modi- fications at positions 1, 6 and 9 are activat- ing in terms of anti-inflammatory and min- eralocorticoid activity, while the two esterifi- cations highly increase the natural lipophil- icity and the drug uptake of FP. Rapid meta- bolization to the inactive moiety due to ester cleavage replacing the thioester moiety at position 17 by a carboxylic acid function contributes to the low systemic activity. Chemical Structure and Glucocorticoid kinetic assay, Högger and Rohdewald [7] measured the Receptor Affinity GR equilibrium dissociation constant of FP in human lung cytosol and reported a value of 0.49 nmol/l. The In general, glucocorticoids have a so-called androstane receptor complex half-life exceeded 10 h, which signifi- structure with 17 carbon atoms arranged in three 6-mem- cantly differs from dexamethasone (1 h), triamcinolone bered rings and one 5-membered ring. Additional modifi- acetonide (4 h) and budesonide (5 h) [7]. Normalization cations to this basic skeletal structure have led to the of the relative receptor affinity to dexamethasone, with development of highly lipophilic corticosteroids such as dexamethasone given a value of 100, resulted in a remark- FP, which has been classified as a potent corticosteroid able value of 1,910 for FP. Results of an equilibrium com- [2]. In this fluoromethyl androstane-17ß-carbothioate, an petition assay (relative receptor affinity: 1,401) are rather extra double bond at positions 1 and 2, two fluorines at close [7]. Despite these receptor pharmacokinetic differ- positions 6 and 9, and an ·-methyl group at position 16 ences, FP provides selectivity for the GR by having only are additionally inserted (fig. 1). The two esterifications at little or no affinity to progestagen, androgen, oestrogen or position 17 (with a propionate group) and at position 20 mineralocorticoid receptors [8]. This GR affinity can be (with a fluorized thio ester, named ‘carbothioate’) highly attributed to the halogenation at the 9· position increas- increase the molecule’s natural lipophilicity, its cutaneous ing both glucocorticoid and mineralocorticoid effects, drug uptake and its binding to human skin tissue [3] as presumably through an electron-withdrawing effect of the well as to the glucocorticoid receptor (GR), a 777-amino- 11ß-hydroxyl group [9]. Furthermore, the insertion of an acid protein member of the superfamily of ligand-recep- ·-methyl substituent at position 16 is known to eliminate tor nuclear receptors [4]. X-ray crystallographic investiga- mineralocorticoid activity [8]. tions revealed that the carbonyl of the 17ß-carbothioate ester substituent lies below the plane of ring D rather than above, as observed for other corticosteroids, and might Effects of the FP-GR Complex explain the rapid enzymatic hydrolysis of FP to its inac- tive metabolite [5]. GR gene regulations have been studied at the molecu- Quantitative structure-activity relationship studies in- lar level. Upon interaction with the GR, FP interferes dicate that FP has a high affinity to the GR reflected by a with the effects of transcription factors such as the activat- fast association and slow dissociation rate, suggesting that ing protein (AP) 1 and the nuclear factor ÎB [10], which the FP-GR complex will be stable [6]. Indeed, using a are involved in the activation of pro-inflammatory cyto- 4 Skin Pharmacol Physiol 2005;18:3–11 Roeder/Schaller/Schäfer-Korting/Korting kines like interleukin (IL) 1· and IL-1ß [11]. For example, range of doses of the glucocorticoid is applied to the skin AP-1-induced transactivation increases rapidly in re- of the inner forearm, and the blanching due to vasocon- sponse to mitogenic factors and tumour promoters and striction is compared visually to a laboratory standard, enhances cell proliferation and activates inflammatory e.g. fluocinolone acetonide [20]. The intensity of blanch- signalling pathways. Like the other corticosteroids, FP ing is then quantified to estimate the topical activity of potently antagonizes AP-1 effects. Inhibition of AP-1 and corticosteroids. Subsequent studies have shown that vaso- nuclear factor ÎB explains anti-inflammatory, immuno- constrictor activity is closely related to anti-inflammatory suppressive and antimitotic glucocorticoid effects in the effects in skin diseases [21]. treatment of psoriasis or eczema [11]. Genes known to be A series of vasoconstrictor studies were undertaken to up-regulated by FP include those encoding for lipocortin I compare FP to topical corticosteroids used for inflamma- and the p11/calpactin-binding protein which are involved tory diseases [22]. FP turned out to be 3 times more in the suppression of the release of arachidonic acid [11]. potent than beclomethasone-17,21-dipropionate and its Furthermore, lipocortin I inhibits phospholipase A2, re- active metabolite, beclomethasone-17-monopropionate, ducing the amount of arachidonic acid released from and equipotent to mometasone furoate, a synthetic 16·- phospholipids [1]. methyl analogue of beclomethasone. FP was 10 times At the cellular level, the beneficial properties of FP in more potent than triamcinolone acetonide, flunisolide terms of inflammation and pathogenic hyperproliferation and fluocinolone acetonide, and intermediate in potency also become obvious from the decrease in markers of between betamethasone-17-valerate (less potent) and clo- inflammation in human endothelial cells, such as the betasol-17-propionate (more potent) [22]. endothelial-leukocyte adhesion molecule and the vascular cell adhesion molecule [12, 13]. Furthermore, FP inhib- its TNF-·-stimulated E-selectin at a concentration of Safety Profile 1 nmol/l in human endothelial cells, whereas 8-fold higher concentrations of budesonide are required for the same Most topical corticosteroids are absorbed in quantities effect [12]. In vitro studies also indicate that FP directly that can produce both systemic and topical adverse suppresses a continuous or excessive activation of neutro- events. These adverse effects are related mainly to actions phil function and might suggest a further role for this on electrolyte and water balance, neoglycogenesis