Two randomized phase III clinical trials evaluating anti-inflammatory dose doxycycline (40-mg doxycycline, USP capsules) administered once daily for treatment of rosacea

Non-antibiotic properties of tetracyclines and their clinical application in dermatology

Dermatologists have used tetracyclines since the 1950s to treat disorders that do not necessarily have an infectious aetiology. Their anti-inflammatory and anti-collagenase properties contribute significantly to their success in treating diseases such as rosacea and acne. This article reviews the non-antibiotic properties of tetracyclines and their clinical application in dermatology.

A new face for old antibiotics: tetracyclines in treatment of amyloidoses

The use of tetracyclines has declined because of the appearance of resistant bacterial strains. However, the indications of nonantimicrobial activities of these drugs have considerably raised interest and triggered clinical trials for a number of different pathologies. About 10 years ago we first reported that tetracyclines inhibited the aggregation of prion protein fragments and Alzheimer's β peptides, destabilizing their aggregates and promoting their degradation by proteases. On the basis of these observations, the antiamyloidogenic effects of tetracyclines on a variety of amyloidogenic proteins were studied and confirmed by independent research groups. In this review we comment on the data available on their antiamyloidogenic activity in preclinical and clinical studies. We also put forward that the beneficial effects of these drugs are a result of a peculiar pleiotropic action, comprising their interaction with oligomers and disruption of fibrils, as well as their antioxidant, anti-inflammatory, antiapoptotic, and matrix metalloproteinase inhibitory activities.

New antibiotic therapies for acne and rosacea

Acne and rosacea compromise a substantial portion of the dermatology clinical practice. Over the past century, many treatment modalities have been introduced with antibiotics playing a major role. Today, both oral and topical antibiotics are used in the management of acne and rosacea, with several novel formulations and/or combination regimens recently introduced. The latest studies suggest anti-inflammatory actions to be the most likely mechanism of antibiotics in acne and rosacea, shifting the focus to subantimicrobial-dose oral antibiotics and/or topical antibiotic regimens as the preferred first-line agents. Here we will discuss the most recent oral and topical antibiotic therapies available for treatment of acne and rosacea, with special focus on efficacy data, indication, dosing, and mechanism of action.

Cathelicidin LL-37: an antimicrobial peptide with a role in inflammatory skin disease

Chronic inflammatory skin diseases such as atopic dermatitis, psoriasis or rosacea are very common. Although their exact pathogenesis is not completely understood all three diseases are characterized by dysregulation of cutaneous innate immunity. Cathelicidin LL-37 is an important effector molecule of innate immunity in the skin and atopic dermatitis, psoriasis or rosacea show defects in cathelicidin expression, function or processing. In atopic dermatitis, cathelicidin induction might be disturbed resulting in defective antimicrobial barrier function. In contrast, psoriasis is characterized by overexpression of cathelicidin. However to date it is unclear whether pro- or anti-inflammatory functions of cathelicidin predominate in lesional skin in psoriasis. In rosacea, cathelicidin processing is disturbed resulting in peptide fragments causing inflammation, erythema and telangiectasias. In this review, the current evidence on the role of cathelicidin LL-37 in the pathogenesis of inflammatory skin diseases will be outlined. As cathelicidin LL-37 might also serve as a future treatment target potential novel treatment strategies for those diseases will be discussed.

Doxycycline indirectly inhibits proteolytic activation of tryptic kallikrein-related peptidases and activation of cathelicidin

The increased abundance and activity of cathelicidin and kallikrein 5 (KLK5), a predominant trypsin-like serine protease (TLSP) in the stratum corneum, have been implicated in the pathogenesis of rosacea, a disorder treated by the use of low-dose doxycycline. Here we hypothesized that doxycycline can inhibit activation of tryptic KLKs through an indirect mechanism by inhibition of matrix metalloproteinases (MMPs) in keratinocytes. The capacity of doxycycline to directly inhibit enzyme activity was measured in surface collections of human facial skin and extracts of cultured keratinocytes by fluorescence polarization assay against fluorogenic substrates specific for MMPs or TLSPs. Doxycycline did inhibit MMP activity but did not directly inhibit serine protease activity against a fluorogenic substrate specific for TLSPs. However, when doxycycline or other MMP inhibitors were added to live keratinocytes during the production of tryptic KLKs, this treatment indirectly resulted in decreased TLSP activity. Furthermore, doxycycline under these conditions inhibited the generation of the cathelicidin peptide LL-37 from its precursor protein hCAP18, a process dependent on KLK activity. These results demonstrate that doxycycline can prevent cathelicidin activation, and suggest a previously unknown mechanism of action for doxycycline through inhibiting generation of active cathelicidin peptides.

A randomized controlled trial of subantimicrobial-dose doxycycline to prevent unscheduled bleeding with continuous oral contraceptive pill use

BACKGROUND

Unscheduled bleeding is the main side effect of continuous oral contraceptive pills (OCPs) and has been correlated with the up-regulation of matrix metalloprotineases (MMPs). The study objective was to determine if prophylactic administration of doxycycline (an MMP inhibitor at low subantimicrobial doses) would prevent unscheduled bleeding during the initiation of a continuous OCP.

STUDY DESIGN

Subjects using cyclic hormonal contraceptives (combined OCPs, patch or ring) without unscheduled bleeding were switched to continuous OCPs (20 mcg ethinyl estradiol/100 mcg levonorgestrel). They were randomized to receive daily doxycycline [sustained-release subantimicrobial dose (40 mg daily)] or placebo for the first 84 days and then observed for an additional 28 days on the continuous OCP alone. The number of bleeding/spotting days and the time in days it took to achieve amenorrhea were compared using a t test.

RESULTS

Sixty-five subjects were randomized. Although the use of doxycycline did not significantly decrease the number of mean bleeding/spotting days in the first 84 days of the study [doxycycline 14.75 (SE 2.30), placebo 17.78 (2.31), p=.36], women who received doxycycline had a significantly earlier onset of amenorrhea [mean last day of bleeding/spotting doxycycline 61.7 (7.7), placebo 85.2 (6.7), p=.03].

CONCLUSION

The coadministration of subantimicrobial-dose doxycycline during initiation of continuous OCPs results in a significant reduction in the length of time needed to achieve amenorrhea.

Effective and evidence-based management strategies for rosacea: summary of a Cochrane systematic review

Rosacea is a common chronic skin disease affecting the face. There are numerous treatment options, but it is unclear which are the most effective. The aim of this review was to assess the evidence for the efficacy and safety of treatments for rosacea. Searches included the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, and Ongoing Trials Registers (updated February 2011). Randomized controlled trials in people with moderate to severe rosacea were included. Fifty-eight trials, including 27 from the original review, comprising 6633 participants were included in this updated review. Interventions included topical metronidazole, oral antibiotics, topical azelaic cream or gel, topical benzoyl peroxide and/or combined with topical antibiotics, sulphacetamide/sulphur, and others. There was some evidence that topical metronidazole and azelaic acid were more effective than placebo. Two trials indicated that doxycycline 40mg was more effective than placebo. There was no statistically significant difference in effectiveness between doxycycline 40mg and 100mg but there were fewer adverse effects. One study reported that ciclosporin ophthalmic emulsion was significantly more effective than artificial tears for treating ocular rosacea. Although the majority of included studies were assessed as being at high or unclear risk of bias, there was some evidence to support the effectiveness of topical metronidazole, azelaic acid and doxycycline (40mg) in the treatment of moderate to severe rosacea, and ciclosporin 0·05% ophthalmic emulsion for ocular rosacea. Further well-designed, adequately powered randomized controlled trials are required.

Interventions for rosacea

BACKGROUND

Rosacea is a common chronic skin condition affecting the face, characterised by flushing, redness, pimples, pustules, and dilated blood vessels. The eyes are often involved and thickening of the skin with enlargement (phymas), especially of the nose, can occur in some patients. A range of treatment options are available but it is unclear which are the most effective.

OBJECTIVES

To assess the evidence for the efficacy and safety of treatments for rosacea.

SEARCH STRATEGY

In February 2011 we updated our searches of the Cochrane Skin Group Specialised Register, the Cochrane Central Register of Controlled Trials (Clinical Trials) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, and Ongoing Trials Registers.

SELECTION CRITERIA

Randomised controlled trials in people with moderate to severe rosacea.

DATA COLLECTION AND ANALYSIS

Study selection, data extraction, assessment of risk of bias, and analyses were carried out by two independent review authors.

MAIN RESULTS

Fifty-eight trials, including 27 from the original review, comprising 6633 participants were included in this updated review. Interventions included topical metronidazole, oral antibiotics, topical azelaic cream or gel, topical benzoyl peroxide and/or combined with topical antibiotics, sulphacetamide/sulphur, and others. Only two studies assessed our primary outcome 'quality of life'.Pooled data from physician assessments in three trials provided some evidence that metronidazole was more effective compared to placebo (RR 1.95, 95% CI 1.48 to 2.56). Three trials provided data, based on participants' assessments, illustrating azelaic acid was more effective than placebo (RR 1.52, 95% CI 1.32 to 1.76).Physician-based assessments in two trials indicated that doxycycline appeared to be significantly more effective than placebo (RR 1.59, 95% CI 1.02 to 2.47 and RR 2.37, 95% CI 1.12 to 4.99). There was no statistically significant difference in effectiveness between 100 mg and 40 mg doses of doxycycline, but there was evidence of less adverse effects with the lower dose (RR 0.25, 95% CI 0.11 to 0.54).One study reported that cyclosporine ophthalmic emulsion was significantly more effective than artificial tears for treating ocular rosacea (for all outcomes).

AUTHORS' CONCLUSIONS

Although the majority of included studies were assessed as being at high or unclear risk of bias there was some evidence to support the effectiveness of topical metronidazole, azelaic acid, and doxycycline (40 mg) in the treatment of moderate to severe rosacea, and cyclosporine 0.5% ophthalmic emulsion for ocular rosacea. Further well-designed, adequately-powered randomised controlled trials are required.

Doxycycline ameliorates the susceptibility to aortic lesions in a mouse model for the vascular type of Ehlers-Danlos syndrome

The vascular form of Ehlers-Danlos syndrome (vEDS), a rare disease with grave complications resulting from rupture of major arteries, is caused by mutations of collagen type III [α1 chain of collagen type III (COL3A1)]. The only, recently proven, preventive strategy consists of the reduction of arterial wall stress by β-adrenergic blockers. The heterozygous (HT) Col3a1 knockout mouse has reduced expression of collagen III and recapitulates features of a mild presentation of the disease. The objective of this study was to determine whether changing the balance between synthesis and degradation of collagen by chronic treatment with doxycycline, a nonspecific matrix metalloproteinase (MMP) inhibitor, could prevent the development of vascular pathology in HT mice. After 3 months of treatment with doxycycline or placebo, 9-month-old HT or wild-type (WT) mice were subjected to surgical stressing of the aorta. A 3-fold increase in stress-induced aortic lesions found in untreated HT mice 1 week after intervention (cumulative score 4.5 ± 0.87 versus 1.3 ± 0.34 in WT, p < 0.001) was fully prevented in the doxycycline-treated group (1.1 ± 0.56, p < 0.001). Untreated HT mice showed increased MMP-9 activity in the carotid artery and decreased collagen content in the aorta; however, in doxycycline-treated animals there was normalization to the levels observed in WT mice. Doxycycline treatment inhibits the activity of tissue MMP and attenuates the decrease in the collagen content in aortas of mice haploinsufficient for collagen III, as well as prevents the development of stress-induced vessel pathology. The results suggest that doxycycline merits clinical testing as a treatment for vEDS.

Rosacea - global diversity and optimized outcome: proposed international consensus from the Rosacea International Expert Group

BACKGROUND

The absence of specific histological or serological markers, the gaps in understanding the aetiology and pathophysiology of rosacea, and the broad diversity in its clinical manifestations has made it difficult to reach international consensus on therapy guidelines.

OBJECTIVES

The main objective was to highlight the global diversity in current thinking about rosacea pathophysiology, classification and medical features, under particular consideration of the relevance of the findings to optimization of therapy.

METHODS

The article presents findings, proposals and conclusions reached by the ROSacea International Expert group (ROSIE), comprising European and US rosacea experts.

RESULTS

New findings on pathogenesis provide a rationale for the development of novel therapies. Thus, recent findings suggest a central role of the antimicrobial peptide cathelicidin and its activator kallikrein-5 by eliciting an exacerbated response of the innate immune system. Cathelicidin/kallikrein-5 also provide a rationale for the effect of tetracyclines and azelaic acid against rosacea. Clinically, the ROSIE group emphasized the need for a comprehensive therapy strategy - the triad of rosacea care - that integrates patient education including psychological and social aspects, skin care with dermo-cosmetics as well as drug- and physical therapies. Classification of rosacea into stages or subgroups, with or without progression, remained controversial. However, the ROSIE group proposed that therapy decision making should be in accordance with a treatment algorithm based on the signs and symptoms of rosacea rather than on a prior classification.

CONCLUSION

The ROSIE group reviewed rosacea pathophysiology and medical features and the impact on patients and treatment options. The group suggested a rational, evidence-based approach to treatment for the various symptoms of the condition. In daily practice this approach might be more easily handled than prior subtype classification, in particular since patients often may show clinical features of more than one subtype at the same time.

Doxycycline 40 mg capsules (30 mg immediate-release/10 mg delayed-release beads): anti-inflammatory dose in rosacea

Anti-inflammatory dose doxycycline 40 mg capsules (30 mg immediate-release and 10 mg delayed-release beads) provide a sub-antimicrobial dose that reduces the inflammatory response in patients with rosacea without producing drug concentrations required to treat bacterial diseases. The efficacy of oral, anti-inflammatory dose doxycycline 40 mg capsules once daily in the treatment of adults with rosacea was demonstrated in two pivotal large, randomized, double-blind, placebo-controlled, multicenter trials. After 16 weeks' therapy, anti-inflammatory dose doxycycline 40 mg was significantly more effective in improving rosacea than placebo, providing a greater reduction in the total inflammatory lesion count (primary endpoint) than placebo. Anti-inflammatory dose doxycycline 40 mg was associated with a rapid onset of action, achieving a significantly greater decrease in total inflammatory lesion count than placebo by the first follow-up visit at week 3 in both studies. Maximum anti-inflammatory efficacy appears to be achieved with doxycycline 40 mg capsules once daily, as no additional improvement in rosacea symptoms was achieved with oral doxycycline 100 mg once daily (usual antibacterial dosage) in a small, randomized, double-blind trial. Anti-inflammatory dose doxycycline 40 mg was generally well tolerated in clinical trials, with most adverse events being of mild to moderate intensity.

[Rosacea 2009 : new advances in pathophysiology, clinical staging and therapeutic strategies]

Rosacea is one of the most common dermatoses of adults. In recent years many studies have contributed to a better understanding of the pathophysiology of rosacea. They suggest that an altered innate immune response is involved in the vascular and inflammatory manifestations seen in rosacea. A good understanding of the disease and its special features is necessary for the differential diagnosis of the many clinical subtypes and for a stage- and phase-specific treatment approach. Topical treatments that are widely accepted are metronidazole and azelaic acid; agents under investigation that show promise include permethrin, calcineurin inhibitors and sulfur compounds. For systemic therapy antibiotics (tetracyclines, macrolides) and recently doxycycline in anti-inflammatory rather than anti-microbial dosages are used, as well as isotretinoin in severe cases. Findings such as rhinophyma and telangiectases can be treated using different laser systems or dermabrasion. This article gives an overview regarding rosacea, a challenging condition with multiple therapeutic options.

The role of tetracyclines in rosacea

There is a great deal of evidence to support the use of tetracycline and doxycycline in the treatment of papulopustular rosacea. Nevertheless, these agents have shared and unique adverse effects and relative contraindications. Recently, subantimicrobial-dose doxycycline was demonstrated to be an effective treatment for rosacea, due to its inherent anti-inflammatory properties. Furthermore, subantimicrobial-dose doxycycline has a more preferable tolerability profile and a lower occurrence of bacterial resistance than traditional-dose doxycycline. To further elucidate the role of tetracycline agents in rosacea, clinical trials that compare these agents with each other as well as with other effective rosacea treatments are called for. Adherence studies comparing oral tetracycline treatment with topical metronidazole treatment may also enhance clinical decision making.

Systemic isotretinoin in the treatment of rosacea - doxycycline- and placebo-controlled, randomized clinical study

BACKGROUND

Systemic isotretinoin has been known for decades to be effective in the treatment of severe forms of rosacea, but it must be used off-label because of the lack of evidence-based data.

PATIENTS AND METHODS

573 patients with rosacea subtype II and III received one of three different dosages of isotretinoin (0.1 mg, 0.3 mg, or 0.5 mg per kg body weight), doxycycline (100 mg daily for 14 days, then 50 mg daily) or placebo in a double-blinded, randomized way for 12 weeks in 35 German centers.

RESULTS

Isotretinoin 0.3 mg/kg proved to be the most effective dose with significant superiority versus placebo. Isotretinoin 0.3 mg/kg showed also significant non-inferiority versus doxycycline with reduction of lesions of 90 % compared to 83 % with doxycycline. Investigators diagnosed complete remission in 24 % and marked improvement in further 57 % of patients with isotretinoin treatment, in contrast to remission in 14 % and marked improvement in 55 % of patients treated with doxycycline. Isotretinoin 0.3 mg/kg revealed a similar safety profile as for the treatment of acne. Isotretinoin 0.5 mg/kg showed more dermatitis facialis as compared to 0.3 mg/kg.

CONCLUSIONS

Isotretinoin 0.3 mg/kg is an effective and well-tolerated therapy option for the treatment of rosacea subtype II and III and can therefore be used successfully as an alternative to therapy with oral antibiotics.

In vivo characterization of doxycycline effects on tear metalloproteinases in patients with chronic blepharitis

PURPOSE

Matrix metalloproteinases (MMPs) have a role in the pathogenesis of rosacea-associated chronic blepharitis. Doxycycline is largely used as a treatment for recalcitrant chronic blepharitis. It has been shown in vitro that doxycycline inhibits MMPs activation. The aim of this study was to investigate in vivo the effect of doxycycline in modulating MMPs in patients with chronic idiopathic blepharitis.

METHODS

Eight patients (6 male, 2 female; mean age 45.7+/-17.5 years) were included in the study. Doxycycline (100 mg) was administered orally, twice a day, for 2 weeks and once a day for an additional 2 weeks. Clinical signs and symptoms were evaluated and scored (0-3) at baseline and after 4 weeks. Total sign (TSS) and total symptom (TSyS) scores were calculated. Tear samples and conjunctival impression cytologies were collected at baseline and after 4 weeks of treatment to evaluate MMP-9 and TIMP-1 expression and activity.

RESULTS

An improvement in TSS (4.5+/-1.1 vs 2.7+/-1.5) and TSyS (6.6+/-1.3 vs. 3.1+/-1.9) was observed after 4 weeks, with significant amelioration of hyperemia, marginal blepharitis, and superficial punctuate keratopathy. Zymography revealed a decrease of MMP-9 activity after 4 weeks. MMP-9 mRNA and protein levels did not change, while an upregulation of TIMP-1 expression was observed.

CONCLUSIONS

This study suggests that 4-week treatment with doxycycline significantly improved symptoms and signs in patients with chronic blepharitis in association with a decrease in MMP-9 activity. Upregulation of TIMP-1 is proposed as a possible mechanism of MMP-9 inactivation.

Rosacea

Rosacea, a common disease in adults, has an extremely variable presentation. Severity is also highly variable and, to some degree, the location of mild end of the rosacea spectrum is in the eye of the beholder. Rosacea has been noted since at least the Middle Ages. The red-faced drunk and the swollen nose of the self-indulgent are images from Shakespeare and Chaucer that have been used in modern political cartoons as well. This association with alcohol and excess is unfortunate since most patients are neither alcoholic nor dissipated.

Gnatophyma and Otophyma

Background:

Phymas are slowly progressive, disfiguring disorders of the face and ears that represent the end stage of rosacea. The most common phyma is rhinophyma, yet similar swellings may occur on the chin (gnatophyma), forehead (metophyma), one or both ears (otophyma), and eyelids (blepharophyma).

Objective: Unlike rhinophyma, otophyma is rarely seen. We report two rare phymas:

a case of gnatophyma and a case of otophyma.

Methods:

A 56-year-old African American man presented with a history of bumps on his chin that had begun about 7 years earlier. Physical examination was remarkable for lobulated plaques on the chin, coalescing into hypertrophic nodules and dilated pores. A 73-year-old African American male presented with bilateral cauliflower-like earlobe growths for the past 17 years.

Results:

A skin biopsy was performed for each patient demonstrating cystic follicular dilatation with keratin plugging, dermal scarring, psoriasiform epidermal hyperplasia, and chronic inflammation of some of the follicles.

Conclusion:

This case report describes a relatively rare gnatophyma and otophyma. Surgical management is well accepted as the best mode of therapy to treat rhinophyma and is becoming a first-line treatment for all phymas.

Safety and efficacy of doxycycline in the treatment of rosacea

Rosacea is a common, chronic, skin condition characterized by recurrent episodes of facial flushing, transient or persistent erythema, papules, pustules, and telangiectasias, in a symmetrical facial distribution. The etiology of rosacea remains unknown and this condition represents a therapeutic challenge because of its chronic nature, progression, potential for disfigurement and psychological impact. Although there is no curative therapy for rosacea, the most widely used systemic agents are oral tetracycline derivatives, including tetracycline, doxycycline, and minocycline. This article reviews the available evidence for the use of doxycycline, a second-generation tetracycline, in the treatment or rosacea.

Current topical and systemic approaches to treatment of rosacea

Rosacea is a common, often overlooked, chronic facial dermatosis characterized by intermittent periods of exacerbation and remission. Clinical subtypes and grading of the disease have been defined in the literature. On the basis of a genetic predisposition, there are several intrinsic and extrinsic factors possibly correlating with the phenotypic expression of the disease. Although rosacea cannot be cured, there are several recommended treatment strategies appropriate to control the corresponding symptoms/signs. In addition to adequate skin care, these include topical and systemic medications particularly suitable for the papulopustular subtype of rosacea with moderate to severe intensity. The most commonly used and most established therapeutic regimens are topical metronidazole and topical azelaic acid as well as oral doxycycline. Conventionally, 100-200 mg per day have been used. Today also a controlled release formulation is available, delivering 40 mg per day using non-antibiotic, anti-inflammatory activities of the drug. Anti-inflammatory dose doxycycline in particular allows for a safe and effective short- and long-term therapy of rosacea. Topical metronidazole and topical azelaic acid also appear to be safe and effective for short-term use. There are indications that a combined therapy of anti-inflammatory dose doxycycline and topical metronidazole could possibly have synergy effects. Further interesting therapy options for the short- and long-term therapy of rosacea could be low-dose minocycline and isotretinoin; however, too little data are available with regard to the effectiveness, safety, optimal dosage and appropriate length of treatment for these medications to draw final conclusions.

Subantimicrobial-dose doxycycline modulates gingival crevicular fluid biomarkers of periodontitis in postmenopausal osteopenic women

BACKGROUND

We recently demonstrated that a 2-year subantimicrobial-dose doxycycline (SDD) regimen (double-masked, placebo-controlled clinical trial) in postmenopausal (PM) women exhibiting mild systemic bone loss (osteopenia) and local bone loss (periodontitis) reduced the progression of periodontal attachment loss (intent-to-treat analysis) and the severity of gingival inflammation and alveolar bone loss (subgroups) without producing antibiotic side effects. We now describe SDD effects on biomarkers of collagen degradation and bone resorption in the gingival crevicular fluid (GCF) of the same vulnerable subjects.

METHODS

GCF was collected from SDD- and placebo-treated PM subjects (n=64 each) at the baseline and 1- and 2-year appointments; the volume was determined; and the samples were analyzed for collagenase activity (using a synthetic peptide as substrate), relative levels of three genetically distinct collagenases (Western blot), a type-1 collagen breakdown product/bone resorption marker (a carboxyterminal telopeptide cross-link fragment of type I collagen [ICTP]; radioimmunoassay), and interleukin-1beta (enzyme-linked immunosorbent assay). Statistical analyses were performed using generalized estimating equations; primary analyses were intent-to-treat.

RESULTS

Collagenase activity was significantly reduced by SDD treatment relative to placebo based on intent-to-treat (P=0.01). ICTP showed a similar pattern of change during SDD treatment, and GCF collagenase activity and ICTP were positively correlated at all time periods (P<0.001). Matrix metalloproteinase (MMP)-8 accounted for approximately 80% of total collagenase in GCF, with much less MMP-1 and -13, and SDD reduced the odds of elevated MMP-8 by 60% compared to placebo (P=0.006).

CONCLUSION

These observations support the therapeutic potential of long-term SDD therapy to reduce periodontal collagen breakdown and alveolar bone resorption in PM women; effects on serum biomarkers of systemic bone loss in these subjects are being analyzed.

The use and safety of doxycycline hyclate and other second-generation tetracyclines

Tetracyclines have long been used to treat a wide variety of medical conditions, especially in the field of dermatology. Unfortunately, safety concerns, especially gastrointestinal (GI), have always been present. Other safety concerns have included tooth development in children, candidiasis, vestibular concerns, photosensitivity/phototoxicity, and more unusual adverse effects such as uncontrolled hypertension. This article first discusses the pharmacological development of the tetracyclines from the first to the second generation versions with an emphasis on the safety concerns, especially with regards to doxycycline hyclate (DH). Second, the adverse effects of the tetracyclines are discussed. Third, the favorable side effect profile of DH delayed release capsules (Doryx) is compared with DH powder contained in tablets (Vibramycin). Fourth, the increased use with a continued favorable safety profile is also discussed concerning the subantimicrobial dosing of DH for acne. Fifth, the safety of periodontic uses of DH is discussed. Last, the favorable safety profiles of the 2006 approved uses of an anti-inflammatory dose of 40 mg doxycycline for rosacea and an extended-release minocycline tablet for acne are also discussed.

Pharmacotherapy of acne

BACKGROUND

Acne results from the interplay of several pathophysiologic factors, in particular seborrhoea, follicular hyperkeratosis, propionibacteria and inflammation. Recently, it has become clear that inflammatory events are important not only in the course, but also in the initiation of the disease.

OBJECTIVE

The study undertook an evaluation of the effectiveness of currently available pharmacotherapeutic treatment options for acne.

METHODS

After a Medline-based literature search, this article critically reviewed substances used topically (among others, retinoids, antimicrobials, salicylic acid and azelaic acid) and systemically (antibiotics, isotretinoin, hormones and zinc) as well as their combinations with respect to pharmacology, clinical efficacy and side effects.

RESULTS

Modern acne pharmacotherapy provides substances that antagonize one or more of the major pathophysiologic factors of acne. When the clinical picture but also patients' motivation and wishes are appropriately considered, current pharmacotherapy of acne is rational and effective.

Anti-inflammatory dose doxycycline (40 mg controlled-release) confers maximum anti-inflammatory efficacy in rosacea

BACKGROUND

Two large clinical trials have recently demonstrated the efficacy of a 40-mg controlled-release formulation of doxycycline in the treatment of rosacea, a dose well below the conventional level of 100 to 200 mg/d. Since no formal dose-response studies have been conducted, the authors analyzed phase 3 data to determine whether a dose-efficacy relationship exists.

METHODS

Standard parametric regression analyses were used to estimate the correlations between dose (mg/kg body weight) and overall drug exposure (area under the curve [AUC]) in a phase 1 pharmacokinetic study and between dose and efficacy (mean change from baseline in total inflammatory lesion count at week 16) in 2 pooled phase 3 clinical efficacy studies. Additional regressions were run at each visit for the clinical efficacy studies to determine whether results differed across visits. A regression analysis was also performed in a subset of patients who showed a greater efficacy response.

RESULTS

We found overall drug exposure (AUC) to have a highly significant correlation with dose (mg/kg) (r=0.49; P=.006). In contrast, clinical efficacy did not correlate with dose at any of the visits at week 3 (r=0.01; P=.85), week 6 (r=0.04; P=.53), week 12 (r<0.01; P=.98), and week 16 (r=0.03; P=.64) or among the subset of patients who showed greater clinical benefit.

CONCLUSIONS

Higher mg/kg doses led to higher plasma concentrations but did not lead to increased clinical efficacy. Anti-inflammatory dose doxycycline (40-mg controlled-release formulation) conferred peak anti-inflammatory efficacy in the treatment of rosacea.