Photoaging and phototoxicity from long-term voriconazole treatment in a 15-year-old girl

Rapid Quantitative Detection of Voriconazole in Human Plasma Using Surface-Enhanced Raman Scattering

There is an increasing demand for rapid detection techniques for monitoring the therapeutic concentration of voriconazole (VRC) in human biological fluids. Herein, a rapid and selective surface-enhanced Raman scatting method for point-of-care determination of VRC in human plasma was developed via a portable Raman spectrometer. This approach has enabled the quantification of the VRC spiked into human plasma at clinical relevant concentrations. A gold nanoparticle solution (Au sol) was used as the SERS substrate, and the agglomerating conditions on its sensitivity were optimized. The method involves the formation of hot spots, and the signal of VRC molecules adsorbed on the surface of the SERS hot spot was amplified by 10⁵. The calibration curve was linear in the range of 0.02-10 ppm, with satisfactory repeatability. The limit of detection was as low as 12.3 ppb. The variation in VRC spectra over time on different substrates demonstrated good reproducibility. Notably, the salting-out extraction method developed in this study was rapid and suitable for the quantitation of drugs in biological samples. Compared with traditional methods, this approach allows for the point-of-care quantification of VRC directly in a complex matrix, which may open up new exciting opportunities for future use of the SERS technique in clinical applications.

Characterization of Aspergillus nidulans Biofilm Formation and Structure and Their Inhibition by Pea Defensin Psd2

Approximately four million people contract fungal infections every year in Brazil, primarily caused by Aspergillus spp. The ability of these fungi to form biofilms in tissues and medical devices complicates treatment and contributes to high rates of morbidity and mortality in immunocompromised patients. Psd2 is a pea defensin of 5.4 kDa that possesses good antifungal activity against planktonic cells of representative pathogenic fungi. Its function depends on interactions with membrane and cell wall lipid components such as glucosylceramide and ergosterol. In the present study, we characterized Aspergillus nidulans biofilm formation and determined the effect of Psd2 on A. nidulans biofilms. After 4 hours, A. nidulans conidia adhered to polystyrene surfaces and formed a robust extracellular matrix-producing biofilm at 24 h, increasing thickness until 48 h Psd2 inhibited A. nidulans biofilm formation in a dose-dependent manner. Most notably, at 10 μM Psd2 inhibited 50% of biofilm viability and biomass and 40% of extracellular matrix production. Psd2 significantly decreased the colonized surface area by the biofilm and changed its level of organization, causing a shortening of length and diameter of hyphae and inhibition of conidiophore formation. This activity against A. nidulans biofilm suggests a potential use of Psd2 as a prototype to design new antifungal agents to prevent biofilm formation by A. nidulans and related species.

Drug-Induced Photosensitivity-From Light and Chemistry to Biological Reactions and Clinical Symptoms

Photosensitivity is one of the most common cutaneous adverse drug reactions. There are two types of drug-induced photosensitivity: photoallergy and phototoxicity. Currently, the number of photosensitization cases is constantly increasing due to excessive exposure to sunlight, the aesthetic value of a tan, and the increasing number of photosensitizing substances in food, dietary supplements, and pharmaceutical and cosmetic products. The risk of photosensitivity reactions relates to several hundred externally and systemically administered drugs, including nonsteroidal anti-inflammatory, cardiovascular, psychotropic, antimicrobial, antihyperlipidemic, and antineoplastic drugs. Photosensitivity reactions often lead to hospitalization, additional treatment, medical management, decrease in patient's comfort, and the limitations of drug usage. Mechanisms of drug-induced photosensitivity are complex and are observed at a cellular, molecular, and biochemical level. Photoexcitation and photoconversion of drugs trigger multidirectional biological reactions, including oxidative stress, inflammation, and changes in melanin synthesis. These effects contribute to the appearance of the following symptoms: erythema, swelling, blisters, exudation, peeling, burning, itching, and hyperpigmentation of the skin. This article reviews in detail the chemical and biological basis of drug-induced photosensitivity. The following factors are considered: the chemical properties, the influence of individual ranges of sunlight, the presence of melanin biopolymers, and the defense mechanisms of particular types of tested cells.

Coccidioidomycosis: a review

Coccidioidomycosis is a fungal infection of the Western hemisphere that is endemic to the soil in areas with limited rainfall. Human and animal infections result with inhalation of arthroconidia. Most often, this is an asymptomatic event. When illness occurs, it is primarily a pneumonic presentation. A small minority of infections eventuate in disseminated disease. Predominately, this presents as meningitis or osteoarticular or integumentary disease. Treatment may not be required for the mildest illness. Azoles are commonly prescribed. Severe infections may require amphotericin B.

[Voriconazole-induced lentigines on photo-exposed skin: A little-known complication]

BACKGROUND

The appearance of diffuse lentigines in children is rare and a genetic syndrome should initially be envisaged. Another little-known cause of photo-distributed lentigines is use of voriconazole. We present a new case in which the original feature is the very short time of onset.

PATIENTS AND METHODS

A 9-year-old immunosuppressed girl treated with voriconazole for 3 months presented lentigines in exposed areas after only 4 weeks of exposure.

DISCUSSION

The literature contains only around ten cases of photo-distributed lentigines under voriconazole in children. The condition can appear very early, as in our case. Voriconazole also appears to induce cutaneous squamous cell carcinomas and even melanoma. The benefit-risk ratio of prescribing this drug must therefore be carefully evaluated, and close clinical monitoring and photoprotection must be instituted.

Drug and chemical induced photosensitivity from a clinical perspective

Drug photosensitivity is a relatively common occurrence and a range of mechanisms may be involved. Some of these mechanisms will be discussed, including the most common, that of drug phototoxicity. Different types of photosensitivity are addressed with respect to clinical presentation, mechanisms and additionally the contribution to our understanding through clinically directed investigations and regulatory requirements. Repeated controlled therapeutic use of drug phototoxicity, with psoralen-UVA (PUVA) photochemotherapy and photodynamic therapy (PDT) will also be discussed. Finally, the potential for drug-induced photocarcinogenesis will also be covered.

Cutaneous Complications in Recipients of Lung Transplants: A Pictorial Review

Lung transplant is now an established modality for a broad spectrum of end-stage pulmonary diseases. According to the International Society for Heart and Lung Transplantation Registry, more than 50,000 lung transplants have been performed worldwide, with nearly 11,000 recipients of lung transplants alive in the United States. With the increasing use of lung transplant, pulmonologists must be cognizant of the common as well as the unique posttransplant dermatologic complications. Immunosuppression, infections, and a variety of medications and environmental exposures can contribute to these complications. This review aims to provide representative pictures and describe the pathogenesis, epidemiologic characteristics, and clinical manifestations of dermatologic complications encountered among recipients of lung transplants.

Inflammation Due to Voriconazole-induced Photosensitivity Enhanced Skin Phototumorigenesis in Xpa-knockout Mice

Voriconazole is an antifungal agent and used as a prophylactic measure, especially in immunocompromised patients. However, there have been several reports of its adverse reactions, namely photosensitivity with intense inflammatory rashes and subsequent skin cancer development. To assess the effects of photosensitizing drugs voriconazole and hydrochlorothiazide (HCTZ) on the enhancement of UV-induced inflammatory responses and UV-induced tumorigenesis, we utilized Xpa-knockout mice, which is DNA repair-deficient and more susceptible to UV-induced inflammation and tumor development than wild-type mice. Administration of voriconazole prior to broadband UVB exposure significantly upregulated multiple inflammatory cytokines compared with the vehicle- or HCTZ-administered groups. Voriconazole administration along with chronic UVB exposure produced significantly higher number of skin tumors than HCTZ or vehicle in Xpa-knockout mice. Furthermore, the investigation of UVB-induced DNA damage using embryonic fibroblasts of Xpa-knockout mice revealed a significantly higher 8-oxo-7,8-dihydroguanine level in cells treated with voriconazole N-oxide, a voriconazole-metabolite during UV exposure. The data suggest that voriconazole plus UVB-induced inflammatory response may be related to voriconazole-induced skin phototumorigenesis.

Voriconazole exposure and the risk of cutaneous squamous cell carcinoma in allogeneic hematopoietic stem cell transplant patients

BACKGROUND

Voriconazole is a commonly used antifungal medication in allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients. In solid organ transplantation, voriconazole use has been associated with the development of cutaneous squamous cell carcinoma (SCC). We sought to determine if voriconazole use was associated with SCC in patients undergoing allo-HSCT.

METHODS

We retrospectively reviewed consecutive adult patients who underwent allo-HSCT at Mayo Clinic from January 2007 through July 2012. Multivariable Cox models were created to assess the relationship of SCC with two time-dependent voriconazole exposure variables: (i) history of voriconazole exposure (yes/no), and (ii) cumulative days of voriconazole use.

RESULTS

In our cohort of 381 allo-HSCT patients, SCC developed in 26 of 312 patients exposed to voriconazole (25 post-voriconazole) and in 1 of 69 patients who received alternative antifungal agent(s). Cumulative incidence of SCC was estimated to be 19% at 5 years post allo-transplant. Cumulative days of voriconazole use was found to be a risk factor for SCC, and this relationship persisted in a multivariable model using previously identified risk factors as covariates (hazard ratio 1.859 for each 180 days of use, P < 0.001).

CONCLUSION

This is the first study, to our knowledge, to identify cumulative days of voriconazole use as a risk factor for SCC development following allo-HSCT, and may help guide appropriate antifungal use in this patient population.

Voriconazole therapeutic drug monitoring: results of a prematurely discontinued randomized multicenter trial

BACKGROUND

Voriconazole (VOR) levels are highly variable, with potential implications to both efficacy and safety. We hypothesized that VOR therapeutic drug monitoring (TDM) will decrease the incidence of treatment failures and adverse events (AEs).

METHODS

We initiated a prospective, randomized, non-blinded multicenter study to compare clinical outcomes in adult patients randomized to standard dosing (clinician-driven) vs. TDM (doses adjusted based on levels). VOR trough levels were obtained on day 5, 14, 28, and 42 (or at completion of drug; ± 3 days). Real-time dose adjustments were made to maintain a range between 1-5 μg/mL on the TDM-arm, while levels were assessed retrospectively in the standard-arm. Patient questionnaires were administered to assess subjective AEs.

RESULTS

The study was discontinued prematurely, after 29 patients were enrolled. Seventeen (58.6%) patients experienced 38 AEs: visual changes (22/38, 57.9%), neurological symptoms (13/38, 34.2%), and liver abnormalities (3/38, 7.9%). VOR was discontinued in 7 (25%) patients because of an AE (4 standard-arm, 3 TDM-arm). VOR levels were frequently out of range in the standard-arm (8 tests >5 μg/mL; 9 tests <1 μg/mL). Three dose changes occurred in the TDM-arm for VOR levels <1 μg/mL. Levels decreased over time in the standard-arm, with mean VOR levels lower at end of therapy compared to TDM (1.3 vs. 4.6 μg/mL, P = 0.008).

CONCLUSIONS

VOR TDM has become widespread clinical practice, based on known variability in drug levels, which impaired accrual in this study. Although comparative conclusions are limited, observations of variability and waning levels over time support TDM.

Voriconazole-associated phototoxic dermatoses and skin cancer

Voriconazole's antifungal spectrum, oral bioavailability, and proven efficacy in treatment of invasive mycoses have led to its widespread off-label use for antifungal prophylaxis. There is an increasing recognition that long-term voriconazole use is associated with accelerated sun-induced skin changes that include acute phototoxicity reactions, photoaging, actinic keratosis and esp. among immunocompromised patients, skin cancers. The mechanisms underlying these dermatologic adverse events are not clearly understood. Population-risks of long-term voriconazole use need to be prospectively investigated. This review aims to provide an in-depth assessment of published literature and highlight salient findings from retrospective studies and case series. A broad practical guideline for assessment and management of these patients is provided.

Voriconazole-associated cutaneous malignancy: a literature review on photocarcinogenesis in organ transplant recipients

This article synthesizes the current data regarding the implication of voriconazole in the development of skin cancer in organ transplant recipients (OTRs) and offers suggestions for additional research. According to Organ Procurement and Transplantation Network data, 28 051 solid organ transplants were performed in 2012. Due to advancements in immunosuppression and management of infectious diseases, survival of OTRs has substantially increased. Voriconazole is a widely prescribed antifungal medication used for prophylaxis and for treatment of invasive fungal infections in OTRs. Case reports describing skin cancer associated with voriconazole exposure emerged shortly after US Food and Drug Administration approval of the drug, and it is now established that voriconazole is an independent risk factor for the development of cutaneous malignancy in lung transplant recipients. The mechanism of voriconazole-induced skin cancer is still unknown and may involve its primary metabolite, voriconazole N-oxide. Here we discuss the current data and potential mechanisms of voriconazole-associated photosensitivity and carcinogenesis and identify areas that require further research.

High cumulative dose exposure to voriconazole is associated with cutaneous squamous cell carcinoma in lung transplant recipients

BACKGROUND

Lung transplant recipients (LTR) have an increased risk of cutaneous squamous cell carcinoma (SCC) due to immunosuppressive therapy. Voriconazole, which is associated with phototoxic side effects in some patients, may be an additional risk factor for SCC in this population.

METHODS

To test whether voriconazole is a risk factor for developing SCC in LTR, we evaluated cumulative exposure to voriconazole in 327 adults who underwent lung transplantation at one center between 1991 and 2010. Voriconazole exposure was assessed as a time-varying covariate. We used survival analysis methods to assess the risk of developing SCC over time.

RESULTS

Exposure to voriconazole was associated with a 2.6-fold increased risk for SCC. This phenomenon was dose-dependent: the risk for SCC increased by 5.6% with each 60-day exposure at a standard dose of 200 mg twice daily. At 5 years after transplant, voriconazole conferred an absolute risk increase for SCC of 28%.

CONCLUSIONS

These results suggest that caution should be taken when using voriconazole in LTR because this drug increases the already high risk for SCC in this population.

Photosensitivity reactions to vandetanib: redevelopment after sequential treatment with docetaxel

Vandetanib (ZD6474, Zactima™) is a novel, orally available inhibitor of different intracellular signaling pathways involved in tumor growth, progression, and angiogenesis, including vascular endothelial growth factor receptor-2, epidermal growth factor receptor, and rearranged during transfection tyrosine kinase activity. The most frequently reported adverse events attributed to vandetanib include diarrhea, elevated aminotransferase, asymptomatic corrected QC interval prolongation, and hypertension. In a few randomized, double-blinded studies, cutaneous adverse events including these general symptoms have been reported, but there are only a few reports on the photosensitivity reaction to vandetanib domestically as conducted by dermatologists. In this report, we describe two cases of photosensitivity reactions induced by vandetanib. After improvement with steroid and antihistamine, the photosensitivity reaction was redeveloped by sequential treatment with docetaxel.

Drug-induced photosensitivity: culprit drugs, management and prevention

Photo-induced drug eruptions are cutaneous adverse events due to exposure to a drug and either ultraviolet or visible radiation. Based on their pathogenesis, they can be classified as phototoxic or photoallergic drug eruptions, although in many cases it is not possible to determine whether a particular eruption is due to a phototoxic or photoallergic mechanism. In this review, the diagnosis, prevention and management of drug-induced photosensitivity are discussed. Diagnosis is based primarily on the history of drug intake and the clinical appearance of the eruption, primarily affecting sun-exposed areas of the skin. Phototesting and photopatch testing can be useful adjuncts in making a diagnosis. The mainstay of management is prevention, including informing patients of the possibility of increased sun sensitivity and the use of sun protective measures. However, once the eruption has occurred, it may be necessary to discontinue the culprit medication and treat the eruption with a potent topical corticosteroid. Drugs that have been implicated in causing photosensitive eruptions are reviewed. Tetracycline, doxycycline, nalidixic acid, voriconazole, amiodarone, hydrochlorothiazide, naproxen, piroxicam, chlorpromazine and thioridazine are among the most commonly implicated medications. We review the medical literature regarding evidence for the culpability of each drug, including the results of phototesting, photopatch testing and rechallenge testing.

Long-term voriconazole and skin cancer: is there cause for concern?

Skin toxicity due to voriconazole is well recognized. Recently, several series have reported skin cancer, particularly cutaneous squamous cell carcinoma (C-SCC), following photosensitivity reactions among patients receiving long-term voriconazole (>12 months). Almost all patients were immunosuppressed, including stem cell and solid organ transplant recipients. A case-control study of lung transplant recipients identified long-term voriconazole (median cumulative dose: 76 grams) and residence in areas of strong sun exposure as independent risk factors for C-SCC. The mechanism(s) by which voriconazole may predispose to skin cancer is not clear. Moreover, the relative contribution of voriconazole and other factors such as immunosuppression, ultraviolet exposure, advanced age and skin type is unknown. Until further data are available, voriconazole should be used carefully for durations >6-9 months, particularly among patients with risk factors for skin cancer. In patients requiring prolonged voriconazole, diligent skin examinations, avoidance of excess sunlight, and liberal use of UV protectants are advisable.

Phototoxicity and photocarcinogenesis associated with voriconazole

The antifungal voriconazole was given its marketing authorization in 2002. Several kinds of adverse effects have been reported, including acute and chronic cutaneous adverse effects, mainly due to a phototoxicity mechanism. More recently, some authors have reported that voriconazole was involved in the occurrence of multiple and often-aggressive cutaneous squamous cell carcinomas if the treatment was maintained for a long time. According to safety data in studies assessing voriconazole effectiveness, 8% of outpatients may experience phototoxic events. An overview of the different types of phototoxicity and of the concerned population was given by the 61 published case reports of photo-induced voriconazole-related skin adverse events (including 18 cases of squamous cell carcinomas). The most likely mechanisms may be phototoxicity directly related to either voriconazole or to its N-oxide main metabolite, and an interaction with retinoid metabolism; moreover, immunodeficiency may enhance the risk of skin cancer. Several issues remain to be investigated, and studies are needed concerning the phototoxicity and photocarcinogenesis of voriconazole and the prognosis of chronic non-malignant skin lesions. Voriconazole prescription must be associated with strict photoprotection; in case of a phototoxic adverse event, another azole may be recommended.

Skin cancer in solid organ transplant recipients: advances in therapy and management: part I. Epidemiology of skin cancer in solid organ transplant recipients

Skin cancer is the most frequent malignancy in organ transplant recipients, 95% of which are nonmelanoma skin cancer, especially squamous cell and basal cell carcinomas. This paper also discusses the incidence of other tumors (eg, melanoma, Merkel cell carcinoma, and Kaposi sarcoma) that are also increased in organ transplant patients compared to the general population. Part I of this two-part series describes the latest data concerning the epidemiologic and pathogenic aspects of nonmelanoma skin cancer development in solid organ transplant recipients. This review also highlights the concept of "field cancerization," represented by extensive areas of actinic damage and epidermal dysplasia, which accounts for increased risk of aggressive skin cancer development in susceptible patients.

Skin cancer in transplant recipients, out of the woods. Scientific retreat of the ITSCC and SCOPE

The International Transplant Skin Cancer Collaborative (ITSCC) is an organization of more than 300 members dedicated to the study and care of skin changes that develop in solid-organ transplant recipients. This group of medical and surgical dermatologists, transplant surgeons and basic science researchers was formed to better understand the basic science of transplant dermatology, and to work collaboratively to address the clinical challenges in this patient population. Transplant patients have an ∼100-fold increased risk of developing cutaneous squamous cell carcinoma than the general population and are also at an increased risk of developing basal cell carcinoma, melanoma, Merkel cell carcinoma and Kaposi's sarcoma. In October 2010, ITSCC and its European counterpart Skin Care in Organ Transplant Patients Europe (SCOPE) held a joint biennial 4-day scientific retreat in the woods near Essex, Massachusetts. In this meeting report we provide an up-to-date distillation of the novel findings presented in the 21 oral abstracts, at the tumor board and within the working groups.

Multifocal aggressive squamous cell carcinomas induced by prolonged voriconazole therapy: a case report

Voriconazole is a treatment for severe fungal infections. Prolonged voriconazole therapy may induce skin reactions, with 1% of severe photosensitivity accidents. Recently the imputability of voriconazole in skin carcinogenesis has been suggested. This report concerns a 55-year-old man suffering from pulmonary aspergillosis who presented a phototoxic reaction a few months after introduction of voriconazole, followed by multiple squamous cell carcinomas of sun-exposed skin areas. After voriconazole discontinuation, no new carcinoma was observed. The detection of EBV and HPV in skin lesions was negative. Exploration of gene mutations involved in skin carcinogenesis showed two variants of the MICR gene. The occurrence of multiple, recurrent, aggressive squamous cell carcinomas is rare with voriconazole, but its imputability is strongly suggested. A plausible hypothesis is that several factors including voriconazole uptake, immunosuppression, and genetic background could explain the phenotype of fast-developing skin carcinomas. Voriconazole therapy should be accompanied by stringent photoprotection and skin monitoring.

Severe phototoxicity associated with long-term voriconazole treatment

Voriconazole is a second-generation triazole antifungal approved for the treatment of invasive fungal infections, particularly with Aspergillus, Candida, Fusarium, and Scedosporium spp. Frequently reported adverse effects of voriconazole include visual disturbance (21 %), elevated liver enzymes (15.6 %) and rashes (7 %), which are largely attributable to drug-induced photosensitivity. We report a case of serious phototoxicity in a 8 year old boy who underwent chemotherapy for AML. He received voriconazole for the treatment and subsequent re-infection prophylaxis after pulmonary aspergillosis. One year after the start of therapy he developed blistering eruptions on his face after minimal sunlight exposure. Recent reports about the development of squamous cell carcinoma and melanoma, respectively, in children during and after oral therapy with voriconazole seem to warrant systematic follow-up investigations of all voriconazole-treated patients.

Voriconazole inhibition of vitamin A metabolism: are adverse events increased in cystic fibrosis patients?

BACKGROUND

As Voriconazole is being used more frequently in cystic fibrosis (CF) patients, we aimed to describe the adverse events associated with voriconazole treatment in this population.

METHODS

We performed a retrospective cohort study of all children with CF who received voriconazole between September 2006 and August 2008.

RESULTS

Five of six CF patients receiving treatment developed photosensitivity, whereas all six patients reported visual disturbances. We report two clinical cases of particular interest: a 7-year-old boy developed striking erythema in the face and upper thorax; a 16-year-old girl who reported unexpected visual disturbances, including scotomas and tunneling vision.

CONCLUSION

Significant adverse effects of voriconazole were noted in all treated CF patients. We speculate that this may be due to suppression of activity of hepatic enzymes involved in all transretinonic acid metabolism coupled with vitamin A supplementation in CF. Consideration should be given to reducing vitamin A supplementation during voriconazole treatment.

Voriconazole exposure and geographic location are independent risk factors for squamous cell carcinoma of the skin among lung transplant recipients

BACKGROUND

Skin cancer, in particular squamous cell carcinoma (SCC), is the most common malignancy after solid-organ transplantation. SCC has been reported in immunosuppressed patients receiving voriconazole, but the agent has not been shown to be a risk factor. Universal voriconazole prophylaxis and alemtuzumab induction are standard in our lung transplant program.

METHODS

We performed a retrospective, case-control study (matched 1:3) among lung transplant recipients at our center from 2003 to 2008.

RESULTS

SCC was diagnosed in 3.1% (17 of 543) of patients at a median follow-up of 36 months. Median time to development of SCC was 19 months post-transplant. Risk factors for SCC by univariate analysis included older age (p = 0.02), residence in locations with high levels of sun exposure (p = 0.0001), single-lung transplant (p = 0.02) and duration (p = 0.03) and cumulative dose (p = 0.03) of voriconazole. Duration of voriconazole (hazard ratio [HR] = 2.1; p = 0.04) and residence in locations with high sun exposure (HR = 3.8; p = 0.0004) were independent risk factors by multivariate analysis. SCC lesions were located on the head and neck in 94% of cases, and 53% had multiple lesions. All patients were treated with surgery. At least one independent lesion developed subsequently in 47% of patients. Local spread and distant metastases each occurred in 7% of cases. There were no deaths among the cases.

CONCLUSIONS

Voriconazole exposure is a risk factor for SCC after lung transplantation, particularly among older patients living in areas with high sun exposure. Voriconazole should be used cautiously in these patients.

Clinical safety and tolerability issues in use of triazole derivatives in management of fungal infections

There has been an increase in the number of patients susceptible to invasive fungal infections (IFIs) leading to a greater need for effective, well tolerated, and easily administered antifungal agents. The advent of triazoles has revolutionized the care of patients requiring treatment or prophylaxis for IFIs. However, triazoles have been associated with a number of adverse events and significant drug–drug interactions. While commonly used, physicians and patients should be aware of the distinct properties of these agents in order to ensure that patients are optimally treated with the least amount of toxicity possible. Clinicians should have a full understanding of the basic pharmacokinetics, absorption, and bioavailability of triazoles. Moreover, knowledge of the drug–drug interactions and potential toxicities of each agent is critical prior to administering a triazole. Careful history taking, thorough review of the patient’s medication list, and detailed discussion with the patients and their families about the efficacy, safety, and tolerability of these agents should be performed. Clinicians treating patients with triazoles should closely follow them, monitor pertinent laboratory tests, and consider measuring drug levels as needed. This article will review the basic pharmacokinetic properties and most frequently encountered adverse events and pitfalls associated with triazoles in clinical practice.

Melanoma associated with long-term voriconazole therapy: a new manifestation of chronic photosensitivity

BACKGROUND

Voriconazole is a triazole antifungal agent approved by the US Food and Drug Administration for serious fungal infections, including with Aspergillus, Fusarium, Pseudallescheria, and Scedosporium species. In initial clinical trials, approximately 2% of patients developed cutaneous reactions, including photosensitivity, cheilitis, and xerosis. Subsequent reports have implicated voriconazole as a cause of severe photosensitivity and accelerated photoaging, pseudoporphyria cutanea tarda, and aggressive squamous cell carcinoma.

OBSERVATION

We report 5 melanoma in situ lesions in the setting of extreme photosensitivity associated with long-term voriconazole therapy.

CONCLUSIONS

We recommend surveillance for skin cancer formation in all patients who require long-term voriconazole treatment, particularly those who manifest signs or symptoms of photosensitivity or chronic photodamage. Further study of the mechanism underlying voriconazole photosensitivity and oncogenesis is warranted.

Lupus erythematosus-like lesions by voriconazole in an infant with chronic granulomatous disease

We report the first case of lupus-like lesions in an infant with chronic granulomatous disease during the treatment with voriconazole for chronic invasive aspergillosis. The lesions disappeared with termination of the treatment.

Chronic phototoxicity and aggressive squamous cell carcinoma of the skin in children and adults during treatment with voriconazole

BACKGROUND

Voriconazole is a broad-spectrum antifungal agent associated with photosensitivity and accelerated photoaging. A possible link with aggressive squamous cell carcinoma (SCC) has also been reported.

OBJECTIVE

We sought to determine the incidence and frequency of cutaneous SCC among patients undergoing long-term treatment with voriconazole who also manifest features of chronic phototoxicity.

METHODS

We conducted a retrospective review of patients who developed one or more squamous cell neoplasms during long-term treatment with voriconazole at 3 academic dermatology centers.

RESULTS

A total of 51 cutaneous SCC were identified in 8 patients (median age 34.5 years, range 9-54) treated with chronic voriconazole (median duration 46.5 months, range 13-60). Underlying diagnoses included graft-versus-host disease, HIV, and Wegener granulomatosis. Signs of chronic phototoxicity and accelerated photoaging included erythema, actinic keratoses, and lentigo formation.

LIMITATIONS

The retrospective nature of the study cannot determine the true population risk of SCC associated with voriconazole therapy. A prospective cohort study is needed.

CONCLUSION

A high index of suspicion for photosensitivity and SCC may be warranted with chronic voriconazole use when used in the setting of concurrent immunosuppression.

Voriconazole-induced phototoxicity masquerading as chronic graft-versus-host disease of the skin in allogeneic hematopoietic cell transplant recipients

Systemic fungal infections pose a significant risk to patients following allogeneic hematopoietic cell transplantation (alloHCT). Voriconazole (Vfend, Pfizer) is an oral second-generation triazole antifungal agent that offers a broad spectrum of coverage against fungal species and is frequently utilized in the post-HCT setting. Herein, we describe 5 patients who were initially believed to be experiencing a flare of cutaneous chronic graft-versus-host disease (cGVHD), but who were actually exhibiting phototoxicity caused by voriconazole. A high index of suspicion for this adverse reaction in the post-alloHCT setting will prevent misdiagnosis and avoid inappropriate therapy for cGVHD.

Voriconazole-induced photosensitivity

Voriconazole is a broad-spectrum triazole antifungal agent indicated for invasive aspergillosis, refractory Candida infections, and other emerging invasive fungal infections. Adverse cutaneous reactions associated with voriconazole therapy occur in fewer than 10% of treated patients and range from mild erythematous eruptions to life-threatening reactions such as the Stevens-Johnson syndrome and toxic epidermal necrolysis. Photosensitivity reactions are an uncommon but characteristic dermatitis in voriconazole recipients, particularly following chronic administration. We report a case of voriconazole-induced phototoxicity in a 50-year-old male with Candida parapsilosis endocarditis that reversed on discontinuation of the drug.

Advances in topical and systemic antifungals

Topical antifungal agents are generally used for the treatment of superficial fungal infections unless the infection is widespread, involves an extensive area, or is resistant to initial therapy. Systemic antifungals are often reserved for the treatment of onychomycosis, tinea capitis, superficial and systemic candidiasis, and prophylaxis and treatment of invasive fungal infections. With the development of resistant fungi strains and the increased incidence of life-threatening invasive fungal infections in immunocompromised patients, some previously effective traditional antifungal agents are subject to limitations including multidrug interactions, severe adverse effects, and their fungistatic mechanism of actions. Several new antifungal agents have demonstrated significant therapeutic benefits and have broadened clinicians' choices in the treatment of superficial and systemic invasive fungal infections.

Voriconazole : a review of its use in the management of invasive fungal infections

Voriconazole (VFEND), a synthetic second-generation, broad-spectrum triazole derivative of fluconazole, inhibits the cytochrome P450 (CYP)-dependent enzyme 14-alpha-sterol demethylase, thereby disrupting the cell membrane and halting fungal growth. In the US, intravenous and/or oral voriconazole is recommended in adults for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, disseminated infections caused by Candida spp., oesophageal candidiasis, and in patients with scedosporiosis and fusariosis who are refractory to or intolerant of other antifungal therapy. In Europe, intravenous and/or oral voriconazole is recommended in adults and paediatric patients of at least 2 years of age for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, fluconazole-resistant serious invasive Candida spp. infections, scedosporiosis and fusariosis. In large randomised trials, voriconazole was an effective and generally well tolerated primary treatment for candidiasis and invasive aspergillosis in adults and adolescents. More limited data also support the use of voriconazole for the treatment of invasive fungal infections in children, in those with rare fungal infections, such as Fusarium spp. or Scedosporium spp., and in those refractory to or intolerant of other standard antifungal therapies. The availability of both parenteral and oral formulations and the almost complete absorption of the drug after oral administration provide for ease of use and potential cost savings, and ensure that therapeutic plasma concentrations are maintained when switching from intravenous to oral therapy. On the other hand, the numerous drug interactions associated with voriconazole may limit its usefulness in some patients. Further clinical experience will help to more fully determine the position of voriconazole in relation to other licensed antifungal agents. In the meantime, voriconazole is a valuable emerging option for the treatment of invasive aspergillosis and rare fungal infections, including Fusarium spp. and Scedosporium spp. infections, and provides an alternative option for the treatment of candidiasis, particularly where the causative organism is inherently resistant to other licensed antifungal agents.