Oral terbinafine: a new antifungal agent

First Synthesis of DBU-Conjugated Cationic Carbohydrate Derivatives and Investigation of Their Antibacterial and Antifungal Activity

The emergence of drug-resistant bacteria and fungi represents a serious health problem worldwide. It has long been known that cationic compounds can inhibit the growth of bacteria and fungi by disrupting the cell membrane. The advantage of using such cationic compounds is that the microorganisms would not become resistant to cationic agents, since this type of adaptation would mean significantly altering the structure of their cell walls. We designed novel, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene)-derived amidinium salts of carbohydrates, which may be suitable for disturbing the cell walls of bacteria and fungi due to their quaternary ammonium moiety. A series of saccharide-DBU conjugates were prepared from 6-iodo derivatives of d-glucose, d-mannose, d-altrose and d-allose by nucleophilic substitution reactions. We optimized the synthesis of a d-glucose derivative, and studied the protecting group free synthesis of the glucose-DBU conjugates. The effect of the obtained quaternary amidinium salts against Escherichia coli and Staphylococcus aureus bacterial strains and Candida albicans yeast was investigated, and the impact of the used protecting groups and the sugar configuration on the antimicrobial activity was analyzed. Some of the novel sugar quaternary ammonium compounds with lipophilic aromatic groups (benzyl and 2-napthylmethyl) showed particularly good antifungal and antibacterial activity.

A detailed insight on the molecular and cellular mechanism of action of the antifungal drugs used in the treatment of superficial fungal infections

Background:

Dermatomycosis, a type of fungal infection that can infect human skin, hair, and nails; day by day the growth of fungal infections ranging from superficial to systemic infection is alarming. Common causative agents included are Candida, Cryptococcus, Aspergillus, and Pneumocystis species.

Objective:

The effective treatment of the fungal infection includes the use of proper antifungal drug therapy. Antifungal drugs are classified into various classes. This paper focuses on understanding and interpreting the detailed molecular and cellular mechanism of action of various classes of an anti-fungal drug along with their important characteristics along with the safety and efficacy data of individual drugs of the particular class.

Methods:

The data selection for carrying out the respective study has been done by studying the combination of review articles and research papers from different databases like Research Gate, PubMed, MDPI, Elsevier, Science Direct, and Med Crave ranging from the year 1972 to 2019 by using the keywords like “anti-fungal agents”, “dermatophytes”, “cutaneous candidiasis”, “superficial fungal infections”, “oral candidiasis”, “amphotericin”, “echinocandins”, “azoles”, “polyenes” “ketoconazole”, “terbinafine”, “griseofulvin”, “azoles”.

Result:

Based on interpretation, we have concluded that the different classes of antifungal drugs follow the different mechanisms of action and target the fungal cell membrane, and are efficient in reducing fungal disease by their respective mechanism.

Conclusion:

The prevention and cure of fungal infections can be done by oral or topical antifungal drugs that aim to destroy the fungal cell membrane. These drugs show action by their respective pathways that are either preventing the formation of ergosterol or squalene or act by inhibiting β-1,3-glucan synthase enzyme. All the drugs are effective in treating fungal infections.

Lysinibacillus Isolate MK212927: A Natural Producer of Allylamine Antifungal ‘Terbinafine’

Resistance to antifungal agents represents a major clinical challenge, leading to high morbidity and mortality rates, especially in immunocompromised patients. In this study, we screened soil bacterial isolates for the capability of producing metabolites with antifungal activities via the cross-streak and agar cup-plate methods. One isolate, coded S6, showed observable antifungal activity against Candida (C.) albicans ATCC 10231 and Aspergillus (A.) niger clinical isolate. This strain was identified using a combined approach of phenotypic and molecular techniques as Lysinibacillus sp. MK212927. The purified metabolite displayed fungicidal activity, reserved its activity in a relatively wide range of temperatures (up to 60 °C) and pH values (6–7.8) and was stable in the presence of various enzymes and detergents. As compared to fluconazole, miconazole and Lamisil, the minimum inhibitory concentration of the metabolite that showed 90% inhibition of the growth (MIC₉₀) was equivalent to that of Lamisil, half of miconazole and one fourth of fluconazole. Using different spectroscopic techniques such as FTIR, UV spectroscopy, 1D NMR and 2D NMR techniques, the purified metabolite was identified as terbinafine, an allylamine antifungal agent. It is deemed necessary to note that this is the first report of terbinafine production by Lysinibacillus sp. MK212927, a fast-growing microbial source, with relatively high yield and that is subject to potential optimization for industrial production capabilities.

p53 transcriptionally regulates SQLE to repress cholesterol synthesis and tumor growth

Cholesterol is essential for membrane biogenesis, cell proliferation, and differentiation. The role of cholesterol in cancer development and the regulation of cholesterol synthesis are still under active investigation. Here we show that under normal-sterol conditions, p53 directly represses the expression of SQLE, a rate-limiting and the first oxygenation enzyme in cholesterol synthesis, in a SREBP2-independent manner. Through transcriptional downregulation of SQLE, p53 represses cholesterol production in vivo and in vitro, leading to tumor growth suppression. Inhibition of SQLE using small interfering RNA (siRNA) or terbinafine (a SQLE inhibitor) reverses the increased cell proliferation caused by p53 deficiency. Conversely, SQLE overexpression or cholesterol addition promotes cell proliferation, particularly in p53 wild-type cells. More importantly, pharmacological inhibition or shRNA-mediated silencing of SQLE restricts nonalcoholic fatty liver disease (NAFLD)-induced liver tumorigenesis in p53 knockout mice. Therefore, our findings reveal a role for p53 in regulating SQLE and cholesterol biosynthesis, and further demonstrate that downregulation of SQLE is critical for p53-mediated tumor suppression.

Squalene epoxidase drives NAFLD-induced hepatocellular carcinoma and is a pharmaceutical target

Nonalcoholic fatty liver disease (NAFLD)-induced hepatocellular carcinoma (HCC) is an emerging malignancy in the developed world; however, mechanisms that contribute to its formation are largely unknown, and targeted therapy is currently not available. Our RNA sequencing analysis of NAFLD-HCC samples revealed squalene epoxidase (SQLE) as the top outlier metabolic gene overexpressed in NAFLD-HCC patients. Hepatocyte-specific Sqle transgenic expression in mice accelerated the development of high-fat, high-cholesterol diet-induced HCC. SQLE exerts its oncogenic effect via its metabolites, cholesteryl ester and nicotinamide adenine dinucleotide phosphate (NADP⁺). Increased SQLE expression promotes the biosynthesis of cholesteryl ester, which induces NAFLD-HCC cell growth. SQLE increased the NADP⁺/NADPH (reduced form of NADP⁺) ratio, which triggered a cascade of events involving oxidative stress-induced DNA methyltransferase 3A (DNMT3A) expression, DNMT3A-mediated epigenetic silencing of PTEN, and activation of AKT-mTOR (mammalian target of rapamycin). In human NAFLD-HCC and HCC, SQLE is overexpressed and its expression is associated with poor patient outcomes. Terbinafine, a U.S. Food and Drug Administration-approved antifungal drug targeting SQLE, markedly inhibited SQLE-induced NAFLD-HCC cell growth in NAFLD-HCC and HCC cells and attenuated tumor development in xenograft models and in Sqle transgenic mice. Suppression of tumor growth by terbinafine is associated with decreased cholesteryl ester concentrations, restoration of PTEN expression, and inhibition of AKT-mTOR, consistent with blockade of SQLE function. Collectively, we established SQLE as an oncogene in NAFLD-HCC and propose that repurposing SQLE inhibitors may be a promising approach for the prevention and treatment of NAFLD-HCC.

Identification of novel glutathione conjugates of terbinafine in liver microsomes and hepatocytes across species

1. Terbinafine (TBF), a common antifungal agent, has been associated with rare incidences of hepatotoxicity. It is hypothesized that bioactivation of TBF to reactive intermediates and subsequent binding to critical cellular proteins may contribute to this toxicity. In the present study, we have characterized the bioactivation pathways of TBF extensively in human, mouse, monkey, dog and rat liver microsomes and hepatocytes. 2. A total of twenty glutathione conjugates of TBF were identified in hepatocytes; thirteen of these conjugates were also detected in liver microsomes. To the best of our knowledge, only two of these conjugates have been reported previously. The conjugates were categorized into three groups based on their mechanism of formation: (a) alkene/alkyne oxidation followed by glutathione conjugation, with or without N-demethylation, (b) arene oxidation followed by glutathione conjugation, with or without N-demethylation, and (c) N-dealkylation followed by glutathione conjugation of the allylic aldehyde, alcohol and acid intermediates. 3. Differences were observed across species in the contributions of these pathways toward overall metabolic turnover. We conclude that, in addition to the glutathione conjugates known to form by Michael addition to the allylic aldehyde, there are other pathways involving the formation of arene oxides and alkene/alkyne epoxides that may be relevant to the discussion of TBF-mediated idiosyncratic drug reactions.

Biofilms and beyond: expanding echinocandin utility

Echinocandins have been in use for over 15 years, starting with the first approval in 2001. Current trends, such as increasing resistance to fluconazole and shifts toward non-albicans spp. of Candida, suggest a growing role for echinocandins, as reflected by recent (2016) updates to guidelines that recommend echinocandins as first-line treatment for candidaemia. The efficacy, tolerability, and safety of echinocandins and their target site of action (1,3-β-d-glucan synthesis) have prompted research into potential new uses, such as for treatment of biofilm infections, MDR Candida auris and dermatophytes. Moreover, new mycobiome discoveries linking inflammatory bowel disease (IBD; for instance Crohn's disease) to fungi have led to preliminary but encouraging data regarding echinocandin therapy and treatment of IBD. In this article, we will review the available evidence and potential utility of echinocandins and 1,3-β-d-glucan synthesis inhibition in these areas of emerging interest.

Lamisil (terbinafine) toxicity: Determining pathways to bioactivation through computational and experimental approaches

Lamisil (terbinafine) may cause idiosyncratic liver toxicity through a proposed toxicological mechanism involving the reactive metabolite 6,6-dimethyl-2-hepten-4-ynal (TBF-A). TBF-A toxicological relevance remains unclear due to a lack of identification of pathways leading to and competing with TBF-A formation. We resolved this knowledge gap by combining computational modeling and experimental kinetics of in vitro hepatic N-dealkylation of terbinafine. A deep learning model of N-dealkylation predicted a high probability for N-demethylation to yield desmethyl-terbinafine followed by N-dealkylation to TBF-A and marginal contributions from other possible pathways. We carried out steady-state kinetic experiments with pooled human liver microsomes that relied on development of labeling methods to expand metabolite characterization. Those efforts revealed high levels of TBF-A formation and first order decay during metabolic reactions; actual TBF-A levels would then reflect the balance between those processes as well as reflect the impact of stabilizing adduction with glutathione and other biological molecules. Modeling predictions and experimental studies agreed on the significance of N-demethylation and insignificance of N-denaphthylation in terbinafine metabolism, yet differed on importance of direct TBF-A formation. Under steady-state conditions, the direct pathway was the most important source of the reactive metabolite with a Vmax/Km of 4.0 pmol/min/mg protein/µM in contrast to model predictions. Nevertheless, previous studies show that therapeutic dosing leads to accumulation of desmethyl-terbinafine in plasma, which means that likely sources for TBF-A would draw from metabolism of both the major metabolite and parent drug based on our modeling and experimental studies. Through this combination of novel modeling and experimental approaches, we are the first to identify pathways leading to generation of TBF-A for assessing its role in idiosyncratic adverse drug interactions.

Computationally Assessing the Bioactivation of Drugs by N-Dealkylation

Cytochromes P450 (CYPs) oxidize alkylated amines commonly found in drugs and other biologically active molecules, cleaving them into an amine and an aldehyde. Metabolic studies usually neglect to report or investigate aldehydes, even though they can be toxic. It is assumed that they are efficiently detoxified into carboxylic acids and alcohols. Nevertheless, some aldehydes are reactive and escape detoxification pathways to cause adverse events by forming DNA and protein adducts. Herein, we modeled N-dealkylations that produce both amine and aldehyde metabolites and then predicted the reactivity of the aldehyde. This model used a deep learning approach previously developed by our group to predict other types of drug metabolism. In this study, we trained the model to predict N-dealkylation by human liver microsomes (HLM), finding that including isozyme-specific metabolism data alongside HLM data significantly improved results. The final HLM model accurately predicted the site of N-dealkylation within metabolized substrates (97% top-two and 94% area under the ROC curve). Next, we combined the metabolism, metabolite structure prediction, and previously published reactivity models into a bioactivation model. This combined model predicted the structure of the most likely reactive metabolite of a small validation set of drug-like molecules known to be bioactivated by N-dealkylation. Applying this model to approved and withdrawn medicines, we found that aldehyde metabolites produced from N-dealkylation may explain the hepatotoxicity of several drugs: indinavir, piperacillin, verapamil, and ziprasidone. Our results suggest that N-dealkylation may be an under-appreciated bioactivation pathway, especially in clinical contexts where aldehyde detoxification pathways are inhibited. Moreover, this is the first report of a bioactivation model constructed by combining a metabolism and reactivity model. These results raise hope that more comprehensive models of bioactivation are possible. The model developed in this study is available at http://swami.wustl.edu/xenosite/ .

New microbial source of the antifungal allylamine "Terbinafine"

The isolated active compound “F12” from the culture media of the Streptomyces sp. KH-F12 was identified using different spectroscopic techniques. Both 1D- and 2D-NMR as well as HRESIMS were utilized to characterize the structure of the isolated compound. ‘F12” was found to be the known systemic antifungal drug terbinafine marketed under the name “Lamisil”. Full analysis of the COSY, HSQC and HMBC enables the full assignment of proton and carbon atoms. Terbinafine is a synthetic allylamine and is reported here for the first time from natural source.

Chronic liver injury induced by drugs: a systematic review

To examine the available literature and summarize what is known about chronic drug-induced liver injury. We reviewed PubMed/MEDLINE through March 2015. We developed a MEDLINE search strategy using PubMed medical subject heading terms chronic liver injury, hepatotoxicity, drug-induced liver injury, cirrhosis and chronic liver disease. We reviewed the reference list of included articles to identify articles missed in the database search. Chronic liver injury from drugs is more common than once thought with prevalence as high as 18% based on large national registries. Patients with cholestatic injury, age ≤65 years, and a long latency period (>365 days) are at increased risk. Of the most common drugs associated with drug-induced liver injury, antibiotics (amoxicillin-clavulanic acid, trimethoprim-sulfamethoxazole, azithromycin) are most likely to cause chronic injury. The presence of autoantibodies is common with chronic DILI, however, it is not diagnostic nor is it specific to autoimmune-like drug-induced liver injury. Immunosuppressive therapy may be necessary for individual cases of autoimmune-like drug-induced liver injury where cessation of the drug alone does not result in resolution of injury, however, the lowest dose should be used for the shortest duration with careful attention to the development of side effects. The effectiveness of treament of cholestatic liver injury with corticosteroids or ursodiol remains unclear. Cases of drug-induced fatty liver, nodular regenerative hyperplasia and peliosis hepatitis are less common subtypes of chronic drug-induced liver injury that deserve special consideration. A high degree of clinical suspicion is required for the diagnosis of chronic drug-induced liver injury and should be suspected in any patient with liver associated enzyme abnormalities that persist out past 6 months of initial presentation. Treatment with drug removal and/or immunosuppressive therapy appears to be effective for the majority of cases. More study into pharmacogenomics and personalized medicine may aid in predicting which patients will go on to develop chronic drug-induced liver injury.

Effects of terbinafine and itraconazole on the pharmacokinetics of orally administered tramadol

BACKGROUND

Tramadol is widely used for acute, chronic, and neuropathic pain. Its primary active metabolite is O-desmethyltramadol (M1), which is mainly accountable for the μ-opioid receptor-related analgesic effect. Tramadol is metabolized to M1 mainly by cytochrome P450 (CYP)2D6 enzyme and to other metabolites by CYP3A4 and CYP2B6. We investigated the possible interaction of tramadol with the antifungal agents terbinafine (CYP2D6 inhibitor) and itraconazole (CYP3A4 inhibitor).

METHODS

We used a randomized placebo-controlled crossover study design with 12 healthy subjects, of which 8 were extensive and 4 were ultrarapid CYP2D6 metabolizers. On the pretreatment day 4 with terbinafine (250 mg once daily), itraconazole (200 mg once daily) or placebo, subjects were given tramadol 50 mg orally. Plasma concentrations of tramadol and M1 were determined over 48 h and some pharmacodynamic effects over 12 h. Pharmacokinetic variables were calculated using standard non-compartmental methods.

RESULTS

Terbinafine increased the area under plasma concentration-time curve (AUC0-∞) of tramadol by 115 % and decreased the AUC0-∞ of M1 by 64 % (P < 0.001). Terbinafine increased the peak concentration (C max) of tramadol by 53 % (P < 0.001) and decreased the C max of M1 by 79 % (P < 0.001). After terbinafine pretreatment the elimination half-life of tramadol and M1 were increased by 48 and 50 %, respectively (P < 0.001). Terbinafine reduced subjective drug effect of tramadol (P < 0.001). Itraconazole had minor effects on tramadol pharmacokinetics.

CONCLUSIONS

Terbinafine may reduce the opioid effect of tramadol and increase the risk of its monoaminergic adverse effects. Itraconazole has no meaningful interaction with tramadol in subjects who have functional CYP2D6 enzyme.

Clinical utility of caspofungin eye drops in fungal keratitis

Treatment of fungal keratitis remains challenging. To date, only the polyenes and azoles are commonly used topically in the management of fungal keratitis. Natamycin, a polyene, is the only antifungal eye drop that is commercially available; the remainder are prepared in-house and are used in an 'off-label' manner. Failure of medical treatment for fungal keratitis is common, hence there is a need for more effective topical antifungal therapy. To increase the antifungal eye drop armamentarium, it is important to investigate the utility of other classes of antifungal agents for topical use. Caspofungin, an echinocandin antifungal agent, could potentially be used to address the existing shortcomings. However, little is known about the usefulness of topically administered caspofungin. This review will briefly explore the incidence, epidemiology and antifungal treatment of fungal keratitis. It will focus primarily on evidence related to the efficacy, safety and practicality of using caspofungin eye drops in fungal keratitis.

Anti dermatophytic therapy--prospects for the discovery of new drugs from natural products

Millions of people and animals suffer from superficial infections caused by a group of highly specialized filamentous fungi, the dermatophytes, which only infect keratinized structures. With the appearance of AIDS, the incidence of dermatophytosis has increased. Current drug therapy used for these infections is often toxic, long-term, and expensive and has limited effectiveness; therefore, the discovery of new anti dermatophytic compounds is a necessity. Natural products have been the most productive source for new drug development. This paper provides a brief review of the current literature regarding the presence of dermatophytes in immunocompromised patients, drug resistance to conventional treatments and new anti dermatophytic treatments.

Stereoselective synthesis of conjugated fluoro enynes

Metalation-electrophilic fluorination of TMS- and TIPS-protected 1,3-benzothiazol-2-yl (BT) propargyl sulfones gave corresponding BT fluoropropargyl sulfones, Julia-Kocienski reagents for the synthesis of fluoro enynes. Both reagents reacted with aldehydes under mild DBU- or LHMDS-mediated conditions, giving high yields of conjugated fluoro enynes with E-stereoselectivity. In comparison to DBU-mediated reactions, stereoselectivity was higher in low-temperature LHMDS-mediated reactions. Two ketones were shown to react as well, using LHMDS as base. In situ removal of the TMS group gave terminal conjugated 2-fluoro 1,3-enynes. Synthetic utility of the fluoro enynes was demonstrated by conversion to internal alkynes and to stereoisomeric fluoro dienes via Sonogashira and Heck couplings.

Terbinafine inhibits oral squamous cell carcinoma growth through anti-cancer cell proliferation and anti-angiogenesis

Terbinafine (TB), an oral antifungal agent used in the treatment of superficial mycosis, has been reported to exert an anti-tumor effect in various cancer cells. However, the effect of TB on oral cancer has not been evaluated. Herein we demonstrate that TB (0-60 µM) concentration-dependently decreased cell number in cultured human oral squamous cell carcinoma (OSCC), KB cells. The anti-proliferation effect of TB was also observed in two other OSCC cell lines, SAS and SCC 15. TB (60 µM) was not cytotoxic and its inhibition on KB cell growth was reversible. [(3) H]thymidine incorporation and flow cytometric analyses revealed that TB-inhibited DNA synthesis and induced the G0/G1 cell-cycle arrest. The TB-induced cell-cycle arrest occurred when the cyclin-dependent kinase 2 activity was inhibited just as the protein levels of p21(cip1) and p27(kip1) were increased. The TB-induced G0/G1 cell-cycle arrest was completely blocked when the expressions of p21(cip1) and p27(kip1) were knocked-down together. Taken together, these results suggest that the p21(cip1) - and p27(kip1) -associated signaling pathways might be involved in the TB-induced anti-proliferation in KB cells. In vivo, TB (50 mg/kg, i.p.) significantly inhibited the KB tumor size. In these TB-treated tumors, increases in the levels of p21(cip1) and p27(kip1) protein and decreases in the number of proliferating cell nuclear antigen-positive cells and the microvessel density were observed. These findings demonstrate for the first time that TB might have potential to serve as a therapeutic tool in the treatment of oral cancer.

Inhibition of ergosterol synthesis by novel antifungal compounds targeting C-14 reductase

The limited number of clinically available antifungal drugs for life-threatening fungal infections has produced an increased demand for new agents. In the course of our screening for novel antifungals, we identified aminopiperidine derivatives which exhibit antifungal activities against the major pathogenic yeasts. Thin layer chromatography (TLC) analysis of the extracted non-saponifiable lipids from Candida albicans showed that these compounds inhibited the ergosterol production in the late step of the synthesis pathway. The results of an LC/Q-Tof MS analysis showed that abnormal sterols including predicted ignosterol, which is known to be accumulated in C. albicans ERG24 deleted mutant, were accumulated in C. albicans treated with one of these derivatives (Compound 1b). Furthermore, the partial disruption of the cell membrane of C. albicans treated with compound 1b was observed by electron microscopy analysis, suggesting its inhibition of ergosterol synthesis. Additionally, a genetic approach demonstrated that ERG24 gene would be responsible for the resistance of Saccharomyces cerevisiae against Compound 1b, strongly indicating that the enzyme targeted by Compound 1b is Erg24p. From all these data, we concluded that these aminopiperidine derivatives are novel antifungal compounds inhibiting C-14 reduction in the ergosterol synthesis pathway.

Clinical utility of voriconazole eye drops in ophthalmic fungal keratitis

Fungal keratitis is one of the major causes of ophthalmic mycosis and is difficult to treat. The range of common antifungal agents available for fungal keratitis remains inadequate and is generally associated with poor clinical outcomes. Voriconazole is a new generation triazole antifungal agent. Only marketed in systemic formulation and, with broad-spectrum activity and high intraocular penetration, voriconazole has demonstrated effectiveness against fungal keratitis. Systemic voriconazole, however, is not without side effects and is costly. Voriconazole eye drops have been prepared extemporaneously and used for the treatment of ophthalmic fungal keratitis. The current article sought to review the literature for evidence related to the effectiveness and safety of topical voriconazole and its corneal penetration into the aqueous humor of the eye. The voriconazole eye drops used are typically of 1% concentration, well tolerated by the eye, and are stable. Despite existing evidence to suggest that the eye drops are effective in the treatment of fungal keratitis, more studies are needed, especially in relation to using the eye drops as first-line and stand-alone treatment, preparation of higher concentrations, and optimal dosing frequency.

Effect of terbinafine and voriconazole on the pharmacokinetics of the antidepressant venlafaxine

This study investigated the effect of terbinafine and voriconazole on the pharmacokinetics of venlafaxine in healthy volunteers. Plasma concentrations of venlafaxine and O-desmethylvenlafaxine (ODV) were measured after ingestion of 75 mg venlafaxine without pretreatment (control), after terbinafine pretreatment, or after voriconazole pretreatment. During the terbinafine phase, the area under the plasma concentration-time curve (AUC(0-infinity)) of venlafaxine was on average 490% (P<0.001) and that of ODV 57% (P<0.001) of the corresponding control value. Terbinafine decreased the AUC(0-infinity) ratio of ODV over venlafaxine by 82% (P<0.001). Voriconazole slightly increased the sum of AUC(0-infinity) of venlafaxine plus AUC(0-infinity) of ODV (active moiety) by 31% (P<0.001). The most likely mechanism for the interaction between terbinafine and venlafaxine is the inhibition of CYP2D6-mediated O-demethylation of venlafaxine, whereas the minor effects of voriconazole are probably due to the inhibition of CYP3A4-, CYP2C9-, or CYP2C19-mediated metabolism of venlafaxine.

Identification and in vitro antifungal susceptibility testing of 200 clinical isolates of Candida spp. responsible for fingernail infections

A total of 200 samples of Candida spp. that are responsible for fingernail infections were isolated in Belo Horizonte, MG, Brazil from April 2004 to May 2005. The samples were identified by routine microbiological techniques and had the following distribution: Candida parapsilosis (40.5%), C. albicans (31.5%), C. tropicalis (26%), and C. guilliermondii (2%). We performed in vitro susceptibility tests with ciclopiroxolamine, terbinafine, ketoconazole, itraconazole, and fluconazole using the CLSI (Clinical and Laboratory Standards Institute) and EUCAST (European Committee on Antibiotic Susceptibility Testing) methodologies. The percentages of agreement between the two methodologies varied from 48 to 100% (the percentage increased to more than 60% for the majority of the samples). Percentages of agreement between the methodologies lower than 60% were seen with ketoconazole (57%) and itraconazole (48%) for samples of C. albicans and with fluconazole (54%) for samples of C. tropicalis. In general, we observed higher agreement between the values of the MICs obtained with both methodologies for ciclopiroxolamine and terbinafine for all tested species. With azoles, lower percentages of agreement between the methodologies were observed for samples C. albicans and C. tropicalis.

Terbinafine increases the plasma concentration of paroxetine after a single oral administration of paroxetine in healthy subjects

OBJECTIVE

Paroxetine is believed to be a substrate of CYP2D6. However, no information was available indicating drug interaction between paroxetine and inhibitors of CYP2D6. The aim of this study was to examine the effects of terbinafine, a potent inhibitor of CYP2D6, on pharmacokinetics of paroxetine.

METHODS

Two 6-day courses of either a daily 150-mg of terbinafine or a placebo, with at least a 4-week washout period, were conducted. Twelve volunteers took a single oral 20-mg dose of paroxetine on day 6 of both courses. Plasma concentrations of paroxetine were monitored up to 48 h after dosing.

RESULTS

Compared with the placebo, terbinafine treatment significantly increased the peak plasma concentration (C(max)) of paroxetine, by 1.9-fold (6.4 +/- 2.4 versus 12.1 +/- 2.9 ng/ml, p < 0.001), and the area under the plasma concentration-time curve from zero to 48 h [AUC (0-48)] of paroxetine by 2.5-fold (127 +/- 67 vs 318 +/- 102 ng/ml, p < 0.001). Elimination half-life differed significantly (15.3 +/- 2.4 vs 22.7 +/- 8.8 h, p < 0.05), although the magnitude of alteration (1.4-fold) was smaller than C(max )or AUC.

CONCLUSION

The present study demonstrated that the metabolism of paroxetine after a single oral dose was inhibited by terbinafine, suggesting that inhibition of CYP2D6 activity may lead to a change in the pharmacokinetics of paroxetine. However, further study is required to confirm this phenomenon at steady state.

Involvement of proapoptotic Bcl-2 family members in terbinafine-induced mitochondrial dysfunction and apoptosis in HL60 cells

Terbinafine (TB, lamisil), a promising world widely used oral-anti-fungal agent, has been used in the treatment of superficial mycosis. In this study, we found that apoptosis but not cell growth arrest was induced by TB (1 microM, for 24 h) in human promyelocytic leukemia (HL60) cells. The apoptotic effect induced by TB in the HL60 cell was not through the general differentiation mechanisms evidenced by evaluation of three recognized markers, including CD11b, CD33, and morphological features. In addition, our results also revealed that TB-induced apoptosis was not through the cellular surface CD 95 receptor-mediated signaling pathway. We found that the mitochondria membrane in the TB-treated HL60 cells was dissipated by decreasing of the electrochemical gradient (DeltaPsi(m)) led to leakage of cytochrome c from mitochondria into cytosol. Such effects were completely blocked by in vitro transfection of the HL60 cells with Bcl-2 overexpression plasmid (HL60/Bcl-2). However, our data found that TB-mediated apoptosis could not be completely prevented in the Bcl-2 over expressed (HL60/Bcl-2) cells. Such results implied that additional mediators (such as caspase-9) other than mitochondria membrane permeability might contribute to the TB-induced cellular apoptosis signaling. This hypothesis was supported by the evidence that administration of caspases-9 specific inhibitor (z-LEHD-fmk) blocked the TB-induced apoptosis. Our studies highlight the molecular mechanisms of TB-induced apoptosis in human promyelocytic leukemia (HL60) cells.

Current use of anti-infectives in dermatology

Dermatologic diseases encompass a broad category of pathologic situations. Infection remains a significant aspect of the pathology faced in patient encounters, and it is natural to expect that anti-infectives play a major element in the armamentarium utilized by dermatologists. Aside from the treatment of the classic bacterial and fungal infections, there are now new uses for antiviral agents to help suppress recurrent disease, such as herpes simplex. There is also the novel approach of using anti-infectives, or agents that have been thought to have antimicrobial activity, to treat inflammatory diseases. This review describes anti-infectives, beginning with common antibiotics used to treat bacterial infections. The discussion will then cover the current use of antivirals. Finally, the description of antifungals will be separated, starting with the oral agents and ending with the topical antimycotics. The use of anti-infectives in tropical dermatology has been purposefully left out, and perhaps should be the subject of a separate review. Cutaneous bacterial infections consist chiefly of those microorganisms that colonize the skin, such as species of staphylococcus and streptococcus. Propionibacterium acnes and certain other anaerobes can be involved in folliculitis, pyodermas and in chronic conditions such as hidradenitis suppurativa.

Estudio de satisfacción con el tratamiento de las micosis en extremidades con terbinafina (SETTA)

INTRODUCTION

The SETTA study is an open-label, multicenter, prospective, observational study carried out in order to evaluate satisfaction with the treatment of mycosis on the extremities with terbinafine.

METHODS

Patients clinically diagnosed with tinea pedis or tinea unguium after a single visit were recruited. Follow up was through a questionnaire that the patient was to send back. The two groups were statistically compared by means of three analyses: descriptive, effectiveness and safety.

RESULTS

In the effectiveness analysis, significant differences were observed in the evolution of the tinea, the overall score and degree of adherence to the treatment, with these being more positive in the group with tinea pedis. In the safety analysis, adverse events, none of them serious, were reported in 24 patients.

CONCLUSIONS

This study reflects a high degree of satisfaction and safety in the use of terbinafine to treat patients with mycosis on the extremities.

Seborrhoeic dermatitis: current treatment practices

Seborrhoeic dermatitis (SD) is a recurrent, chronic inflammation of the skin that occurs on sebum rich areas such as the face, scalp and chest, characterised by red scaly lesions. The are many studies indicating that Malassezia yeasts play an important role in the aetiology of this condition, most of the evidence for which comes from demonstrated responsiveness to treatment with antifungal agents. Its aetiology, however, is far from being resolved. Some believe that it is the immune response of the skin to the Malassezia that is the cause of the disease. Traditional treatments of SD have been the use of keratolytic agents or corticosteroids. Since the discovery of ketoconazole, a considerable amount of research has been focused on determining the efficacy of various antifungal agents. This article reviews clinical trial data on treatment options available for SD.

Inhibition of human vascular endothelial cells proliferation by terbinafine

We have demonstrated previously that terbinafine (TB), an oral antifungal agent used in the treatment of superficial mycosis, suppresses proliferation of various cultured human cancer cells in vitro and in vivo by inhibiting DNA synthesis and activating apoptosis. In our study, we further demonstrated that TB at a range of concentrations (0-120 microM) dose-dependently decreased cell number in cultured human umbilical vascular endothelial cells (HUVEC). Terbinafine was not cytotoxic at a concentration of 120 microM, indicating that it may have an inhibitory effect on the cell proliferation in HUVEC. The TB-induced inhibition of cell growth rate is reversible. [(3)H]thymidine incorporation revealed that TB reduced the [(3)H]thymidine incorporation into HUVEC during the S-phase of the cell-cycle. Western blot analysis demonstrated that the protein levels of cyclin A, but not cyclins B, D1, D3, E, CDK2 and CDK4, decreased after TB treatment. The TB-induced cell-cycle arrest in HUVEC occurred when the cyclin-dependent kinase 2 (CDK2) activity was inhibited just as the protein level of p21 was increased and cyclin A was decreased. Pretreatment of HUVEC with a p21 specific antisense oligonucleotide reversed the TB-induced inhibition of [(3)H]thymidine incorporation. Taken together, these results suggest an involvement of the p21-associated signaling pathway in the TB-induced antiproliferation in HUVEC. Capillary-like tube formation and chick embryo chorioallantoic membrane (CAM) assays further demonstrated the anti-angiogenic effect of TB. These findings demonstrate for the first time that TB can inhibit the angiogenesis.

Comparative evaluation of the efficacy and safety of two doses of terbinafine (500 and 1000 mg day-1) in the treatment of cutaneous or lymphocutaneous sporotrichosis. Vergleichende Bewertung der Wirksamkeit und Sicherheit zweier Terbinafin-Dosierungen (500 und 1000 mg/Tag) in der Therapie der kutanen und lymphokutanen Sporotrichose

The aim of this study was to evaluate the safety and efficacy of oral terbinafine (500 and 1000 mg day(-1)) in the treatment of cutaneous or lymphocutaneous sporotrichosis. A culture for Sporothrix schenckii was required for inclusion into this multicentre, randomized, double-blind, parallel-group study. Patients received either 250 mg b.i.d. or 500 mg b.i.d. oral terbinafine for up to a maximum of 24 weeks and were assessed up to 24 weeks post-treatment. The main efficacy outcome measure was cure, defined as no lesion and absence of adenopathy at the end of follow-up. Adverse events (AEs), laboratory tests, vital signs and ophthalmological examinations were also assessed. Sixty-three patients (14-85 years of age) were treated with 500 mg day(-1) (n = 28) or 1000 mg day(-1) terbinafine (n = 35). The majority of patients were cured after 12-24 weeks of treatment, and the response was dose-dependent throughout the study and at the end of follow-up. The cure rate was significantly higher in patients treated with 1000 mg day(-1) terbinafine compared with those treated with 500 mg day(-1) terbinafine (87% vs. 52%, respectively; P = 0.004). There were no cases of relapse after 24 weeks of follow-up in the 1000 mg day(-1) terbinafine group, compared with six relapses in the terbinafine 500 mg day(-1) group. Terbinafine was well tolerated and the frequency of drug-related AEs was slightly higher in the 1000 mg treatment group. Both doses of terbinafine were well-tolerated and effective for the treatment of sporotrichosis. The 1000 mg day(-1) terbinafine dose was more efficacious than 500 mg day(-1) in the treatment of cutaneous or lymphocutaneous sporotrichosis.

Topical therapy for fungal infections

Fungi often infect the skin surface and subsequently invade the stratum corneum to avoid being shed from the skin surface by desquamation. Pharmacologic agents applied to the surface of the skin in the form of creams, lotions, or sprays, readily penetrate into the stratum corneum to kill the fungi (fungicidal agents), or at least render them unable to grow or divide (fungistatic agents). Thus, topical therapies work well to rid the skin of topical fungi and yeasts. Azole drugs such as miconazole, clotrimazole, and ketoconazole are fungistatic, limiting fungal growth but depending on epidermal turnover to shed the still-living fungus from the skin surface. Allylamines and benzylamines such as terbinafine, naftifine, and butenafine are fungicidal, actually killing the fungal organisms. Fungicidal drugs are often preferred over fungistatic drugs for treatment of dermatophytic fungal infections, since treatment times as short as one application daily for 1 week are associated with high cure rates. Furthermore, patients often stop treatments when the skin appears healed, usually after about a week of treatment. If this short-term treatment is stopped, fungi recur more often when fungistatic, rather than fungicidal, drugs have been used. Yeast infections such as those caused by Candida albicans respond less well to allylamine drugs. The azole drugs are often preferred for these types of infections. Nail infections are difficult to cure with topical therapies because the infections usually occur under the nail instead of on top of it and products penetrate poorly, if at all, through the nail plate. Infections of hair follicles, nails, and widespread infections often require systemic treatments. Antifungal agents are compounded into many different types of vehicles. Patients often prefer to treat weeping infections with spray formulations. Most physicians prescribe branded products in cream or lotion bases. Cost is a factor dictating prescription choice, especially since most products work well regardless of mechanism of action. Cost becomes especially important when infections involve large areas of the body surface. This article reviews various treatments of cutaneous fungal infections, with special emphasis on cure rates and rationales for choosing particular products.

In vitro and in vivo studies of the anticancer action of terbinafine in human cancer cell lines: G0/G1 p53-associated cell cycle arrest

Terbinafine (TB) (Lamisil), a promising oral antifungal agent used worldwide, has been used in the treatment of superficial mycosis. In our study, we demonstrated that TB dose-dependently decreased cell number in various cultured human malignant cells. Flow cytometry analysis revealed that TB interrupts the cell cycle at the G0/G1 transition. The TB-induced cell cycle arrest in colon cancer cell line (COLO 205) occurred when the cyclin-dependent kinase (cdk) system was inhibited just as the levels of p53, p21/Cip1 and p27/Kip1 proteins were augmented. In the TB-treated COLO 205, the binding between p53 protein and p53 consensus binding site in p21/Cip1 promoter DNA probe was increased. Pretreatment of COLO 205 with p53-specific antisense oligodeoxynucleotide decreased the TB-induced elevations of p53 and p21/Cip1 proteins, which in turn led to arrest in the cell cycle at the G0/G1 phase. Moreover, in the p53 null cells, HL60, TB treatment did not induce cell cycle arrest. Taken together, these results suggest an involvement of the p53-associated signaling pathway in the TB-induced antiproliferation in COLO 205. We further examined whether administration of TB could affect the growth of tumors derived from human colon cancer cells in an in vivo setting. COLO 205 cells implanted subcutaneously in nude mice formed solid tumor; subsequent intraperitoneal injections of TB (50 mg/kg) led to obvious decline in tumor size, up to 50-60%. In these tumors, increases in the p21/Cip1, p27/Kip1 and p53 proteins and the occurrence of apoptosis were observed. Combined treatment with TB and nocodazole (ND), a clinically used anticancer agent, potentiated the apoptotic effect in COLO 205. These findings demonstrate for the first time that TB can inhibit the proliferation of tumor cells in vitro and in vivo.

Terbinafine-associated hepatotoxicity

Terbinafine, an orally and topically active agent licensed for treatment of dermatophytic infection, has gained rapid worldwide acceptance in medical practice. Despite its fairly benign profile of adverse reactions, liver toxicity has occasionally been linked to terbinafine. This report describes a patient with severe cholestatic hepatitis associated with use of terbinafine. The patient was treated successfully with corticosteroids after partial response to ursodeoxycholic acid and cholestyramine. We attempt to identify risk factors for terbinafine-induced hepatotoxicity by an analytical review of all relevant literature. The mechanism underlying terbinafine hepatotoxicity could be more than just an idiosyncratic reaction. 7,7-dimethylhept-2-ene-4-ynal (TBF-A), the allylic aldehyde metabolite of terbinafine, may play a role in the pathogenesis of its hepatotoxicity. Our analysis supports monitoring patients clinically and measuring liver biochemistry through periodic blood tests, after confirming normal liver function at the onset of therapy with terbinafine. Early detection of abnormal hepatic function should prompt immediate discontinuation of this drug along with further evaluation.

Antifungal therapy--state of the art at the beginning of the 21st century

The most relevant information on the present state of the art of antifungal chemotherapy is reviewed in this chapter. For dermatomycoses a variety of topical antifungals are available, and safe and efficacious systemic treatment, especially with the fungicidal drug terbinafine, is possible. The duration of treatment can be drastically reduced. Substantial progress in the armamentarium of drugs for invasive fungal infections has been made, and a new class of antifungals, echinocandins, is now in clinical use. The following drugs in oral and/or intravenous formulations are available: the broad spectrum polyene amphotericin B with its new "clothes"; the sterol biosynthesis inhibitors fluconazole, itraconazole, and voriconazole; the glucan synthase inhibitor caspofungin; and the combination partner flucytosine. New therapy schedules have been studied; combination therapy has found a significant place in the treatment of severely compromised patients, and the field of prevention and empiric therapy is fast moving. Guidelines exist nowadays for the treatment of various fungal diseases and maintenance therapy. New approaches interfering with host defenses or pathogenicity of fungal cells are being investigated, and molecular biologists are looking for new targets studying the genomics of pathogenic fungi.

Simultaneous determination of terbinafine HCL and triamcinolone acetonide by UV derivative spectrophotometry and spectrodensitometry

A binary mixture of terbinafine hydrochloride and triamcinolone acetonide was determined by three different methods. The first one concerned with determination of both drugs using first derivative (D(1)) spectrophotometric technique at 297 and 274 nm over concentration ranges of 5-30 and 4-24 microg ml(-1), with mean percentage accuracies 99.90+/-0.67 and 100.25+/-0.49, respectively. The second method depends on ratio-spectra 1st derivative (RSD(1)) spectrophotometry at 298 and 248 nm over the same concentration ranges with mean percentage accuracies 100.22+/-0.51 and 99.93+/-0.56, respectively. The spectrodensitometric analysis provides a rapid and precise method for the separation and quantitation of both terbinafine hydrochloride and triamcinolone acetonide. The method depends on the quantitative densitometric evaluation of thin layer chromatogram of terbinafine hydrochloride and triamcinolone acetonide at 283 and 238 nm over concentration ranges of 5-25 and 2.5-22.5 microg spot(-1), with mean percentage accuracies 100.66+/-0.51 and 100.27+/-0.73, respectively. The suggested procedures were checked using laboratory prepared mixtures and were successfully applied for the analysis of their pharmaceutical preparations. The three methods retained their accuracy and precision when applying the standard addition technique. The results obtained by applying the proposed methods were statistically analysed and compared with those obtained by a reported method.

Evaluation of terbinafine treatment in Leishmania chagasi-infected hamsters (Mesocricetus auratus)

The objective of the present study was to assess the effect of terbinafine treatment in hamsters infected with Leishmania chagasi. Four of five groups of hamsters were infected with 3 x 10(7) L. chagasi promastigotes by the intracardiac route and submitted to different treatments of 30 days duration starting on the 30th day after inoculation. Group 1 was treated with 100mg/kg terbinafine PO, group 2 was treated with 80 mg/kg Glucantime IM, and group 3 was treated with a combination of the same dose of each drug by the same routes. Group 4 (control) received vehicle (Tween 80 [0.1%]+CMC[0.5%]+H(2)O [0.5 ml], PO). Spleen parasite burden and spleen relative weight were determined 3 days after the end of the treatment. The results were analyzed by the Kruskal-Wallis test (P < 0.05). There was no difference between the infected untreated and terbinafine-treated groups in spleen parasite burden (15.81+/-15.81 vs. 13.00+/-12.94, respectively). Terbinafine plus Glucantime (6.11+/-5.90) and Glucantime alone (4.83+/-4.82) significantly reduced spleen parasite burden compared to the infected untreated group (15.81+/-15.81, P<0.01). There was a difference in the relative weight of the spleen between the naïve and the infected untreated groups (2.5+/-0.2 vs. 9.8+/-1.0, respectively) as well as between the naïve and terbinafine groups (2.5+/-0.2 vs. 10.0+/-1.4, respectively). Glucantime alone and Glucantime plus terbinafine (2.5+/-0.2 and 4.2+/-0.6) significantly reduced the weight of the spleen in comparison with the infected untreated group. Even so, the spleen parasite burden was directly related to spleen weight. Terbinafine alone at the dose and schedule used had no effect on spleen parasite burden or relative spleen weight of L. chagasi-infected hamsters.

Evaluation of the efficacy and tolerability of oral terbinafine (Daskil) in patients with seborrhoeic dermatitis. A multicentre, randomized, investigator-blinded, placebo-controlled trial

BACKGROUND

Previous uncontrolled trials have suggested that oral terbinafine, an antimycotic allylamine compound, could be useful in the treatment of seborrhoeic dermatitis.

OBJECTIVES

To investigate in a placebo-controlled trial the clinical efficacy of oral terbinafine (Daskil(R), Mipharm, Milan, Italy) in patients with moderate to severe seborrhoeic dermatitis.

METHODS

Sixty outpatients (mean +/- SD age 37 +/- 11 years; 32 men and 28 women) with moderate to severe seborrhoeic dermatitis were enrolled in a multicentre, randomized, placebo-controlled, investigator-blinded, parallel-group, 12-week study. After a 2-week wash-out period, enrolled patients were randomized to treatment with oral terbinafine 250 mg daily (n = 30) or placebo (moisturizing ointment) (n = 30) applied twice daily for 4 weeks (weeks 0-4). Patients were followed up for an additional 8 weeks after completion of treatment and were clinically evaluated at weeks 0, 2, 4 and 12 by an investigator unaware of the patient's type of treatment. The primary end-point of the study was clinical evaluation of erythema, scaling and itching, each scored on a 0-3 scale. A global clinical score, representing the sum of each evaluated symptom, was also calculated.

RESULTS

Demographic and clinical data were equally balanced between the placebo and terbinafine groups. All enrolled patients concluded the study. At baseline, the mean +/- SD global clinical score was 7.4 +/- 1.3 in the placebo group and 7.7 +/- 1.0 in the terbinafine-treated group. At weeks 4 and 12 the mean +/- SD global clinical score in the placebo group was 5.9 +/- 1.7 and 6.3 +/- 1.2, respectively, which was not significantly different from baseline. As compared with baseline values and the placebo group, terbinafine treatment significantly (P < 0.0001, Tukey-Kramer test) reduced the mean +/- SD global clinical score (to 1.0 +/- 1.1 at week 4, and 1.2 +/- 1.4 at week 12), as well as the individual erythema, scaling and itching scores. No serious adverse events were recorded during the study in either group.

CONCLUSIONS

This is the first controlled trial that has shown oral terbinafine to be effective in the treatment of moderate to severe seborrhoeic dermatitis. Clinical improvement following 4 weeks treatment with terbinafine was maintained 8 weeks after completing treatment.

Association between terbinafine and arthralgia, fever and urticaria: symptoms or syndrome?

PURPOSE

The antifungal agent terbinafine has been approved for marketing in The Netherlands since 1992. Adverse drug reactions (ADRs) may occur in about 10% of the patients, the majority gastrointestinal disorders and skin reactions. Since the introduction of terbinafine, the Netherlands Pharmacovigilance Foundation Lareb received eight reports of arthralgia during the use of this drug. In four reports the additional presence of skin reactions was mentioned, two of these reports concerned urticaria. Two patients who reported arthralgia also had a fever. These reports were described in more detail, and analysed statistically in order to determine whether symptoms are interrelated.

METHODS

All reports with known gender and a reporting date between 1 March 1992 and 1 January 1999, concerning patients older than 10 years, were included. The extent to which the symptoms urticaria, fever and arthralgia were interrelated was examined by logistic regression modelling.

RESULTS

Case series as well as the results of the statistical analysis show a clustering of symptoms among reports of patients using terbinafine. Both urticaria and arthralgia were statistically significantly associated with reports on terbinafine compared to all other reports in the database.

CONCLUSION

The findings might point towards a clustering of these symptoms in patients using terbinafine. Possibly these symptoms have a shared aetiology, presumably an immunological reaction.

Systemic antifungal therapy

Systemic antifungal therapy for superficial mycoses has advanced greatly since the introduction of griseofulvin in 1958. The discovery of the azole antifungal compounds, ketoconazole, itraconazole, and fluconazole, allowed for a broader spectrum of treatment and a shorter treatment duration. Terbinafine, through a unique mechanism of action, has a fungicidal power not seen previously in the other antifungals. It is important to use our knowledge of the pharmacology in combination with clinical experience and cost of therapy in order to select the proper drug. The search to identify new oral antifungal agents should continue, since none of the five currently used drugs fulfill the criteria of the "ideal" antifungal.

Comparative efficacies of terbinafine and fluconazole in treatment of experimental coccidioidal meningitis in a rabbit model

A rabbit model of coccidioidal meningitis was used to compare the therapeutic efficacies of terbinafine (TBF) and fluconazole (FCZ). Hydrocortisone acetate-treated New Zealand White male rabbits were infected intracisternally with either 2.2 x 10(4) or 6.4 x 10(4) Coccidioides immitis arthroconidia. Oral treatment with polyethylene glycol 200 (PEG) twice daily (n = 8), TBF twice daily (n = 9; 200 mg/kg of body weight/day), or FCZ once daily (n = 8; 80 mg/kg/day) began on day 5 and continued for 21 days. Mean survival times were 20, 24, and 32 days for rabbits treated with PEG, TBF, and FCZ, respectively. All of the FCZ-treated animals (100%; P = 0.003), 56% of the TBF-treated animals (P = 0.4), and 25% of the PEG-treated animals survived the length of the study. Both FCZ and TBF were effective at reducing the incidence of paresis. Only FCZ was effective at reducing most neurological and systemic signs. FCZ treatments resulted in lower cerebrospinal fluid (CSF) protein concentrations and leukocyte counts and faster clearing of CSF fungal cultures compared with those for PEG-treated controls, but TBF treatments had no significant effect on these parameters. Neither drug affected CSF glucose levels. Mean serum TBF levels by bioassay were within the range of 3.5 to 6.2 microgram/ml at 1, 2, and 4 h postdosing and 0.35 to 7.0 microgram/ml at 14 h postdosing. No TBF was detected in CSF. Mean FCZ levels (24 to 25.5 h postdosing) by bioassay were 16.4 to 19.2 and 13.5 to 19.2 microgram/ml in serum and CSF, respectively. The reduction in the numbers of CFU in the spinal cord and brain was over 100-fold (P = 0.0005) in FCZ-treated animals and 2-fold (P </= 0.2) in TBF-treated animals compared with those in PEG-treated animals. Histopathologic severity (semiquantitative scoring system) was significantly attenuated by FCZ treatment (P = 0. 05) and was slightly attenuated by TBF treatment compared with that for the controls. In conclusion, TBF appeared to have a slight effect on survival, histology, and reduction of the numbers of CFU in tissue; however, these effects were not significant. FCZ was effective at controlling coccidioidal meningitis.

Microbiological assay for terbinafine hydrochloride in tablets and creams

The optimization of a microbiological assay, applying the cylinder-plate method, for the determination of the antifungal terbinafine hydrochloride is described. Using a strain of Aspergillus flavus ATCC 15546 as the test organism, terbinafine hydrochloride at concentrations ranging from 0.125 to 0.5 microg ml(-1) could be measured in tablets and creams. A prospective validation of the method showed that the method was linear (r=0. 9999), precise (intra-day: CV=0.48%-tablets and 0.43%-creams; inter-day: CV=0.98%-tablets and 0.64%-creams) and accurate (it measured the added quantities). The method shows results that confirm its precision, not differing significantly the others methods described in the literature. We conclude that the microbiological assay is satisfactory for quantitation of in vitro antifungal activity of terbinafine.

Quantitative analysis of terbinafine (Lamisil) in human and minipig plasma by liquid chromatography tandem mass spectrometry

A method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the determination of terbinafine in human and minipig plasma has been developed and validated. The method used positive-ion mode for monitoring terbinafine, and used a stable isotope labelled terbinafine as the internal standard. Subsequent to acetonitrile protein precipitation, the supernatant was directly (unfiltered) injected onto the LC column (retention time approximately 4.3 min) for analysis. Interday and intraday accuracy and precision were assessed from the relative recoveries (observed concentration in percent of the nominal value) of spiked samples analyzed on three different days. The lower limit of quantitation (LLOQ) was 0.0679 ng/mL in human and minipig using a plasma sample volume of 0.08 mL. The method was fast, specific, and exhibited ruggedness. Furthermore, the use of turbulent flow chromatography (TurboFlow LC/MS/MS) coupled to mass spectrometry for direct analysis of terbinafine in plasma is discussed. The technique allowed direct introduction of plasma with satisfactory chromatographic peak shape and increased throughput.

Determination of terbinafine (Lamisil) in human hair by microbore liquid chromatography/tandem mass spectrometry

An analytical method for the determination of terbinafine (Lamisil(R)) in human hair was developed and validated. Human hair (10 mg) was hydrolyzed in 0.50 mL of 5.0 N sodium hydroxide for 1.5 h. The aqueous layer was extracted with 1.5 mL of n-hexane. The organic layer was separated and re-extracted with 0.20 mL of formic acid (12.5%)/2-propanol (85:15, v/v). The aqueous layer was separated and 0.010 mL of the aqueous extract was injected onto a reversed-phase microbore (50 x 1.0 mm i.d.) column for analysis by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The instrument was equipped with an electrospray ionization (ESI) interface and operated in the positive ion mode of detection. Interday and intraday accuracy and precision were assessed from the relative recoveries of spiked samples analyzed on three different days. The method showed excellent specificity and ruggedness with a lower limit of quantitation of 10 ng/g (i.e., 10 ppb) using 10 mg of human hair.