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Biomedical subjects

John Koo

Publications and source records attributed to John Koo.

17 recordsLinked to original sources
PubMed2005

Update on the mechanisms and efficacy of biological therapies for psoriasis.

Biologically based agents (biologics) are novel therapeutic options in the treatment of moderate-to-severe psoriasis. Unlike traditional systemic anti-psoriatic drugs, which are chemically synthesized, these agents are unique in that they are derived from living organisms and hence called "biologics." In addition, they are the first group of "custom-designed" molecules that precisely target steps in the pathogenesis of psoriasis. The specificity of these biologics can theoretically avoid the side effects of the prebiologically developed systemic agents including the effects of hepatotoxicity, nephrotoxicity, and bone marrow suppression. However, there is also a tendency for a more precisely targeted agent to have a less overall efficacy. Due to the varying efficacies and high costs of the new biologic agents that are currently approved for psoriasis in the United States, the precise way they fit into the range of treatments for moderate-to-severe psoriasis should be defined pending future clinical experiences.

Adalimumab↗
PubMed2005

Psychopharmacologic therapies in dermatology: an update.

Many patients who have skin disorders have associated psychosocial issues. Psychotropic agents with improved side-effect profiles are available to allow physicians who are not psychiatrists to manage patients who have psychiatric conditions with agents that are effective, simple to administer, and generally well tolerated. Dermatologists who wish to help their patients who have psychodermatologic conditions can enhance their armamentarium by becoming familiar with the use of a few selected psychotropic agents. This article reviews the current status and future directions of psychopharmacology for the major types of psychopathologies encountered in dermatology practice.

Humans↗
PubMed2005

UVB phototherapy and skin cancer risk: a review of the literature.

BACKGROUND: UVB phototherapy is a common treatment modality for psoriasis and other skin diseases. Although UVB has been in use for many decades, many clinicians are hesitant to use this type of phototherapy because of concern over increasing the skin cancer risk. Over the past 20 years, numerous studies have been published examining this issue, but a consensus or analysis of the skin cancer risk is required for the dermatologist to make an educated risk-benefit analysis. OBJECTIVE: To assess the risk of skin cancer associated with UVB phototherapy. METHODS: All prospective or retrospective studies were identified in MEDLINE from 1966 to June 2002. Bibliographies were searched to identify any additional studies examining this issue. All studies that attempted to quantify or qualify any additional skin cancer risk from UVB phototherapy were included. Study selection was performed by two independent reviewers. RESULTS: Eleven studies (10 of which concerned psoriasis patients), involving approximately 3400 participants, were included. Of note, three of the studies involved the same cohort: members of the 16-center US Psoralen plus UVA (PUVA) Follow-up Study: Other than the most recent Finnish study, all studies eventually showed no increased skin cancer risk with UVB phototherapy. One of the PUVA cohort studies examined genital skin cancers, and found an increased rate of genital tumors associated with UVB phototherapy, although this study has not been duplicated. CONCLUSION: The evidence suggests that UVB phototherapy remains a very safe treatment modality.

Humans↗
PubMed2005

A review of acitretin, a systemic retinoid for the treatment of psoriasis.

Acitretin is a second-generation, systemic retinoid that has been approved for the treatment of psoriasis since 1997. It can be considered one of the treatments of choice for pustular and erythrodermic psoriasis. However, the efficacy of acitretin as a monotherapy for plaque psoriasis is less, although it is often used in combination therapy with other systemic psoriasis therapies, especially ultraviolet B or psoralen plus ultraviolet A phototherapy, to increase efficacy. Such combination treatments may potentially minimise toxicity by using lower doses of each of the two agents. All systemic retinoids are potent teratogens. The most common side effects are mucocutanous effects such as cheilitis and hair loss, which are dose-dependent. Acitretin is not immunosuppressive, is generally safe for long-term use and has no time limit restrictions, which makes it useful in combination therapy and for maintenance therapy.

Acitretin↗
PubMed2004

Combination therapy to treat moderate to severe psoriasis.

In patients with moderate-to-severe psoriasis, remission can be difficult to achieve and sustain. Both acutely acting and long-term maintenance agents are needed. Speed and efficiency of available monotherapies tend to be inversely proportional to safety. Combination, rotational, and sequential approaches are often more effective and safer than single-agent therapy. Combining agents with complementary adverse effect profiles is preferable. Apparent synergistic enhancement is seen with most paired combinations of the four major therapies: acitretin, phototherapy (ultraviolet B/psoralen plus ultraviolet A), cyclosporine, and methotrexate. Of those, only cyclosporine in combination with psoralen plus ultraviolet A is contraindicated because of increased cancer risk. Combinations of each of those major therapies with topical agents (retinoids, steroids, vitamin D derivatives, and others) have been used with varying efficacy and safety. The immunomodulators, hydroxyurea and thioguanine, have also shown some success in combination therapy. The new biologic agents with their novel modes of action and adverse effect profiles may prove to be important adjuncts in combination/rotational/sequential approaches. In some cases, monotherapy (with either systemic agents or phototherapy) adequately controls moderate to severe disease. A regimen using a single agent has the advantages of lower cost and greater adherence by the patient. For any number of reasons, however, including loss of efficacy, adverse effects, or cumulative or acute toxicity-and especially the inability to clear resistant lesions-a single modality will not be adequate. Using two or more therapies is thus the rule rather than the exception for most patients with moderate-to-severe psoriasis, but picking a combination that serves to balance safety and efficacy needs careful consideration, especially since no evidence-based treatment guidelines exist.

Acitretin↗
PubMed2004

Psoriasis.

Explore the source record for details and available documents.

Humans↗
PubMed2004

Pimozide in dermatologic practice: a comprehensive review.

Pimozide is an antipsychotic drug of the diphenylbutylpiperidine class. In the US, it is FDA-approved only as a backup treatment for Gilles de la Tourette syndrome, although it has been used in other countries for many years as a treatment for schizophrenia. In the past 20 years, pimozide has been found to be especially efficacious in the treatment of monosymptomatic hypochondriacal psychoses and is used by psychiatrists and dermatologists for this off-label purpose. In particular, pimozide is considered the treatment of choice for delusions of parasitosis. In addition, pimozide has been found to be efficacious in the treatment of body dysmorphic disorder, metastatic melanoma, trichotillomania, and trigeminal and postherpetic neuralgia. This review aims to familiarize physicians, especially dermatologists, on the uses of pimozide in dermatologic practice. A review of the literature was performed and the relevant information synthesized to give a complete overview of the drug and its therapeutic uses in dermatology.

Antipsychotic Agents↗
PubMed2003

Validity and reliability of patient reported outcomes used in psoriasis: results from two randomized clinical trials.

BACKGROUND: Two Phase III randomized controlled clinical trials were conducted to assess the efficacy, safety, and tolerability of weekly subcutaneous administration of efalizumab for the treatment of psoriasis. Patient reported measures of psoriasis-related functionality and health-related quality of life and of psoriasis-related symptom assessments were included as part of the trials. OBJECTIVE: To assess the reliability, validity, and responsiveness of the patient reported outcome measures that were used in the trials - the Dermatology Life Quality Index (DLQI), the Psoriasis Symptom Assessment (PSA) Scale, and two itch measures, a Visual Analog Scale (VAS) and the National Psoriasis Foundation (NPF) itch measure. METHODS: Subjects aged 18 to 70 years with moderate to severe psoriasis for at least 6 months were recruited into the two clinical trials (n = 1095). Internal consistency reliability was evaluated for all patient reported outcomes at baseline and at 12 weeks. Construct validity was evaluated by relations among the different patient reported outcomes and between the patient reported outcomes and the clinical assessments (Psoriasis Area and Severity Index; Overall Lesion Severity Scale; Physician's Global Assessment of Change) assessed at baseline and at 12 weeks, as was the change over the course of the 12 week portion of the trial. RESULTS: Internal consistency reliability ranged from 0.86 to 0.95 for the patient reported outcome measures. The patient reported outcome measures were all shown to have significant construct validity with respect to each other and with respect to the clinical assessments. The four measures also demonstrated significant responsiveness to change in underlying clinical status of the patients over the course of the trial, as measured by the independently assessed clinical outcomes. CONCLUSIONS: The DLQI, the PSA, VAS, and the NPF are considered useful tools for the measurement of dermatology-related limitations of functional ability and the frequency, severity and impact of psoriasis symptoms on patients' lives and psoriasis-related quality of life.

Adolescent↗
PubMed2003

Psychocutaneous drug therapy.

Many patients with skin disorders have psychosocial issues associated with their chief complaints. New psychotropic agents with superior side effect profiles have become available to allow nonpsychiatric physicians to manage psychiatric patients safely with psychotropic agents that are effective, simple to administer, and well tolerated. Dermatologists who wish to help their patients with psychodermatologic conditions can greatly enhance their therapeutic armamentarium by becoming familiar with the use of a few selected psychotropic agents. This article reviews the current status and future directions of psychopharmacology for the 4 major types of psychopathologies encountered in a dermatology practice (depression, obsessive-compulsive disorder, anxiety, and delusional disorder) with the intent of guiding dermatologists in the choice of a psychotropic agent for patients with psychological component to their skin disorder.

Anxiety Disorders↗
PubMed2003

Traditional Chinese medicine in dermatology.

Traditional Chinese medicine (TCM) is an alternative method of therapy that can be administered in oral, topical, or injectable forms. It emphasizes the importance of using many herbs that are combined in different formulations for each individual patient. Since it is not possible to discuss all applications of TCM in every skin disorder, psoriasis and atopic dermatitis are used as the prototypes in illustrating the use of TCM. A number of studies have shown the usefulness of TCM in the treatment of these skin conditions, and thus it is worthwhile for dermatologists throughout the West to gain some familiarity with this method. We attempt to provide a general overview of TCM through a discussion of efficacy, mechanisms of action, and side effects of various TCMs. A warning regarding the possible contamination of TCMs is also included. In the future, perhaps a better understanding of TCM will be gained through more systematic analysis and controlled studies with a placebo arm. It is our hope that this article will provide dermatologists with a more complete understanding of the role and ramifications of TCM therapy.

Chemistry, Pharmaceutical↗
PubMed2003

Case studies in severe psoriasis: A clinical strategy.

Individuals with moderate-to-severe psoriasis perceive that the disease exerts profound emotional, social and physical effects on their lives, and a significant percentage report that they do not consider their treatment sufficiently aggressive. A survey of individuals with a variety of chronic diseases reveals that those with psoriasis have the lowest estimation of their health-related quality of life, lower than that of patients with arthritis, congestive heart failure, chronic lung disease or depression. Although psoriasis can be treated effectively, many treatments are associated with long-term risks. Toxicity-sparing treatment strategies that include combination, rotational and sequential regimens can help to control moderate-to-severe psoriasis while reducing risk. Algorithms for the treatment of moderate-to-severe psoriasis detail possible options for specific types of psoriasis and for patients with specific needs. The purpose of the algorithms is to make optimum use of phototherapy, traditional cytotoxic and immunosuppressive agents, retinoids, and newer biologic agents.

Acitretin↗
PubMed2003

The efficacy of topical tazarotene monotherapy and combination therapies in psoriasis.

Tazarotene (Tazorac, Allergan, Inc.) is the first topical retinoid approved for the treatment of plaque psoriasis. It has a similar onset of action compared to potent topical steroids and has the advantage of a longer remission. The common side effects associated with the drug include skin irritation (including pruritus), erythema and a burning sensation. To overcome some of these shortcomings, it has been used in combination with steroids, calcipotriene and phototherapy. Combination therapy not only results in a decrease in adverse side effects, but also enhanced efficacy. Clinical study data have shown that combination therapy is just as important as tazarotene monotherapy, if not more.

Administration, Cutaneous↗
PubMed2002

A randomized, double-blind, placebo-controlled study of clobetasol propionate 0.05% foam in the treatment of nonscalp psoriasis.

BACKGROUND: Topical corticosteroids are the primary treatment for mild to moderate psoriasis. Foam preparations of corticosteroids offer potential cosmetic and pharmacodynamic advantages over cream and ointment vehicles. A clobetasol propionate foam product is as effective as clobetasol propionate solution in the treatment of scalp psoriasis. AIM: To evaluate the safety and efficacy of clobetasol propionate foam in the treatment of psoriasis involving sites other than the scalp. METHODS: Eighty-one subjects with mild to moderate psoriasis were randomized in a 3 : 1 ratio to receive clobetasol propionate foam vs. placebo foam treatment in this double-blind study of psoriasis involving nonscalp sites. The investigator's and subject's global assessment of the response at week 2 (or at the end of treatment) and at week 4 (follow-up) and the severity of erythema, scaling, and plaque thickness were assessed. Safety was assessed from reported adverse events. RESULTS: After 2 weeks of treatment, there was significantly greater improvement with clobetasol propionate foam compared with placebo foam in both investigator's and subject's global assessment of the response (P < 0.0005). The improvement with clobetasol propionate foam was still present at the 4-week follow-up visit. Adverse effects were generally limited to mild to moderate application site reactions. No subjects withdrew because of adverse events. CONCLUSIONS: Clobetasol propionate foam is more effective than placebo in the treatment of nonscalp psoriasis. Twice-daily applications are well tolerated, compliance exceeds 90%, cosmetic characteristics are acceptable, and the medication may eliminate the need for separate scalp and body prescriptions.

Administration, Topical↗
PubMed2002

Vitamin D and scalp psoriasis.

Calcipotriene has been shown to be safe and effective for the treatment of psoriasis. For scalp psoriasis, the safety advantage of this nonsteroid agent is as important as its efficacy. Even though monotherapy with calcipotriene solution may not always be efficacious for severe scalp psoriasis, many patients are managed effectively with a sequential therapy regimen consisting of 3 phases. In phase 1 (clearing), patients apply clobetasol solution or gel in the morning and calcipotriene solution in the evening daily for 2 weeks. After the scalp psoriasis improves, clobetasol is reduced to weekends and calcipotriene solution is applied on weekdays (phase 2, transitional). Phase 3 is maintenance on calcipotriene solution alone to prevent recurrence. For patients with recalcitrant scalp psoriasis-where only a clobetasol-strength, superpotent topical corticosteroid is effective-a flip-flop therapy regimen has been proposed that allows for the safe, prolonged use of clobetasol solution by limiting its treatment to twice a day for 2-week periods with the use of calcipotriene solution twice a day for a minimum of 2 weeks during the corticosteroid-free in-between periods.

Administration, Topical↗
PubMedDate not supplied

How do you foster medication adherence for better acne vulgaris management?

Suboptimal medication adherence is one of the major reasons for treatment failure among patients with acne vulgaris. Motivating patients to adhere to treatment, especially during the maintenance phase, remains a challenge. Although the literature on medication adherence in the acne vulgaris patient population is sparse, the available literature on patients with dermatologic and nondermatologic disorders suggests that a multifactorial approach, combining nonpharmacologic interventions and effective, well tolerated, and simplified drug regimens, appears to be associated with the greatest success. Furthermore, it is important to evaluate the patient for underlying affective disorders (e.g., depression) that can undermine adherence. The dermatologist can play a major role in enhancing patient adherence by prescribing adherence-enhancing therapeutic regimens and by forming a therapeutic alliance with patients.

Acne Vulgaris↗
PubMedDate not supplied

Rosacea, light, and phototherapy.

The long-established notion that rosacea is worsened by light is of particular concern in the phototherapy of diseases such as psoriasis, eczema, or vitiligo, which often can be coexistent with rosacea. A literature search was conducted and much evidence was found to challenge this belief that light adversely affects rosacea. In fact, more patients actually improved with sunlight in a more recent published survey. Several other studies have also shown that rosacea patients were similar to control subjects in sun exposure, solar skin damage, and sun sensitivity. Additionally, all clinical trials to date have failed to find a difference between rosacea patients and control subjects when challenged with ultraviolet light. Thus, phototherapy with rosacea may be safer than is commonly believed.

Humans↗