Liver failure and transplantation after itraconazole treatment for toenail onychomycosis

Hepatotoxicity of Antibiotics and Antifungals and Their Safe Use in Hepatic Impairment

Idiosyncratic drug-induced liver injury (DILI) is a rare and unpredictable form of hepatotoxicity. While its clinical course is usually benign, cases leading to liver transplantation or death can occur. Based on modern prospective registries, antimicrobials including antibiotics and antifungals are frequently implicated as common causes. Amoxicillin-clavulanate ranks as the most common cause for DILI in the Western World. Although the absolute risk of hepatotoxicity of these agents is low, as their usage is quite high, it is not uncommon for practitioners to encounter liver injury following the initiation of antibiotic or antifungal therapy. In this review article, mechanisms of hepatoxicity are presented. The adverse hepatic effects of well-established antibiotic and antifungal agents are described, including their frequency, severity, and pattern of injury and their HLA risks. We also review the drug labeling and prescription guidance from regulatory bodies, with a focus on individuals with hepatic impairment.

Efficacy and safety of fosravuconazole L-lysine ethanolate, a novel oral triazole antifungal agent, for the treatment of onychomycosis: A multicenter, double-blind, randomized phase III study

Fosravuconazole L‐lysine ethanolate (F‐RVCZ) is a prodrug of ravuconazole, a novel triazole antifungal agent, exerting broad and potent antifungal activity. The efficacy and safety of F‐RVCZ, compared with a placebo, were investigated in a multicenter, double‐blind, randomized study of Japanese onychomycosis patients with 25% or more clinical involvement of the target toenail. Subjects (n = 153) were randomly assigned to receive F‐RVCZ (100 mg RVCZ, n = 101) or placebo (n = 52) p.o. once daily for 12 weeks. The primary end‐point was the rate of complete cure (clinical cure [0% clinical involvement of the target toenail] plus mycological cure [negative potassium hydroxide examination]) at week 48 (36‐week post‐treatment visit). Secondary end‐points were changes over time in the efficacy and mycological effect of F‐RVCZ. Safety was also evaluated. The complete cure rate at week 48 was significantly higher with F‐RVCZ (59.4%, 60/101) than the placebo (5.8%, 3/52) in the full analysis set (P < 0.001). The mycological cure rate at week 48 was also significantly higher with F‐RVCZ (82.0%, 73/89) than the placebo (20.0%, 10/50, P < 0.001). Regarding safety, adverse events were observed in 83.2% (84/101) and 80.8% (42/52), and adverse drug reactions (ADR) in 23.8% (24/101) and 3.8% (2/52) of F‐RVCZ and placebo subjects, respectively. ADR were mild to moderate in severity, with none being serious. F‐RVCZ (equivalent to 100 mg ravuconazole) administrated once daily for 12 weeks was more effective than placebo and tolerable in patients with onychomycosis, suggesting it to be a promising drug for onychomycosis treatment.

An exploration of the optimum dosage and number of cycles of itraconazole pulse therapy for severe onychomycosis

Although standard itraconazole pulse therapy is a well-established regimen for toenail onychomycosis, the cure rate for onychomycosis remains low. To evaluate the efficacy and safety of different cycles of itraconazole pulse therapy, determine the optimal dosage and number of cycles for onychomycosis. A total of 90 outpatients of our hospital with onychomycosis were randomised into three treatment groups: (1) standard itraconazole pulse therapy (200 mg twice per day, 1 week each month for three pulses); (2) long-term pulse therapy (200 mg twice per day, 1 week each month for six pulses); (3) low-dose and long-term pulse therapy (200 mg/d, 1 week per month for six pulses) and were followed up for 15 months. Of the initial patients, the trial was completed by 81 patients. The complete cure rates were 32.43% for three cycles and 75% for six cycles (P < .001). For six cycles, despite the administration of half-dose for patients weighing no more than 55 kg, there was no statistical difference in the complete cure rate (P = .862). Long-term therapy is effective and safe for the treatment of toenail onychomycosis. For patients weighing no more than 55 kg, long-term half-dose itraconazole pulse therapy is recommended .

[A Case of Liver Dysfunction Requiring Hospital Admission after Taking Oral Itraconazole for the Treatment of Kerion Celsi]

  67-year-old female patient developed drug-induced liver dysfunction after taking oral itraconazole (ITCZ) for the treatment of kerion celsi. Red papules appeared on the temporal area of the patient one month prior to her visit to our clinic. The patient presented with a nodule with yellow crust, erosion, infiltration, and hair loss on the area. Diagnosis of kerion celsi caused by Trichophyton rubrum was made from clinical, pathological, and mycological findings. Laboratory data showed normal liver function, and the patient was not taking any other medication, thus, daily oral ITCZ 100 mg was started. The skin lesion improved, but severe liver dysfunction was found 1 month after starting ITCZ. Oral ITCZ was therefore terminated, and the patient was admitted to a medical ward for the treatment of liver dysfunction. Hepatobiliary enzymes increased after admission: AST 232 IU/L, ALT 465 IU/L, T-bil 6.1 mg/dL, and D-bil 3.9 mg/dL. The patient was kept at rest and was given oral ursodeoxycholic acid. Hepatobiliary enzymes returned to normal level 2 1/2 months after starting ITCZ. The skin lesion healed without further treatment. No recurrence was observed. It is noteworthy that liver function has to be carefully monitored during treatment with oral ITCZ.

Hepatic Failure in a Patient Receiving Itraconazole for Pulmonary Histoplasmosis-Case Report and Literature Review

Severe cases of itraconazole-induced hepatotoxicity have been reported; however, these events are thought to occur very rarely. The available literature is comprised largely of individual case reports and small series that do not report the itraconazole serum concentration at the time of the severe adverse event or apply an objective scale to assess probability of the event being related to drug exposure. We report a case of severe hepatotoxicity after 6 months of itraconazole therapy for histoplasmosis, resulting in acute hepatic failure (aspartate transaminase >20× and alanine transaminase >15× upper limit normal), in the setting of therapeutic serum concentrations (5 mg/mL). Both the Naranjo probability scale and the Roussel Uclaf causality assessment method were used to assess the probability of a causality relationship showing a "probable" and "highly probable" association with itraconazole exposure, respectively. The available literature describing severe hepatotoxicity resulting in hepatic failure associated with itraconazole is also reviewed.

Comparative Hepatotoxicity of Fluconazole, Ketoconazole, Itraconazole, Terbinafine, and Griseofulvin in Rats

Oral ketoconazole was recently the subject of regulatory safety warnings because of its association with increased risk of inducing hepatic injury. However, the relative hepatotoxicity of antifungal agents has not been clearly established. The aim of this study was to compare the hepatotoxicity induced by five commonly prescribed oral antifungal agents. Rats were treated with therapeutic oral doses of griseofulvin, fluconazole, itraconazole, ketoconazole, and terbinafine. After 14 days, only ketoconazole had significantly higher ALT levels (p = 0.0017) and AST levels (p = 0.0008) than the control group. After 28 days, ALT levels were highest in the rats treated with ketoconazole followed by itraconazole, fluconazole, griseofulvin, and terbinafine, respectively. The AST levels were highest in the rats treated with ketoconazole followed by itraconazole, fluconazole, terbinafine, and griseofulvin, respectively. All drugs significantly elevated ALP levels after 14 days and 28 days of treatment (p < 0.0001). The liver enzyme levels suggested that ketoconazole had the highest risk in causing liver injury followed by itraconazole, fluconazole, terbinafine, and griseofulvin. However, histopathological changes revealed that fluconazole was the most hepatotoxic, followed by ketoconazole, itraconazole, terbinafine, and griseofulvin, respectively. Given the poor correlation between liver enzymes and the extent of liver injury, it is important to confirm liver injury through histological examination.

Risk of oral antifungal agent-induced liver injury in Taiwanese

AIM

Oral antifungal agent-induced liver injury is a common safety concern that may lead to patients' hesitation in treating fungal infections such as onychomycosis. This study evaluated risk of drug-induced liver injury (DILI) caused by oral antifungal agents in Taiwanese populations.

METHODS

A population-based study was conducted by analyzing who used oral antifungal agents from 2002 to 2008 from the Taiwan National Health Insurance Database. A comparison control group was randomly extracted from the remainder of the original cohort.

RESULTS

Of the 90,847 oral antifungal agents users, 52 patients had DILI. Twenty-eight DILI cases used ketoconazole, 12 fluconazole, eight griseofulvin, three itraconazole and two terbinafine. The incidence rates (IR) of DILI per 10,000 persons were 31.6, 4.9, 4.3, 3.6 and 1.6 for fluconazole, ketoconazole, griseofulvin, itraconazole and terbinafine, respectively. Longer exposure duration increased the risk of DILI, with IR for exposure duration ≥ 60 defined daily dose (DDD) of 170.9, 62.5, and 36.1 per 10,000 persons for ketoconazole, itraconazole and terbinafine, respectively. Patients taking antifungal agents had higher incidences of developing DILI compared with those in the control group after adjusting for age, gender and co-morbidities (relative risk 2.38, P < 0.001). All of the six patients with fatal DILI used fluconazole. Old age and fluconazole increased the risk of oral antifungal-induced fatal DILI.

CONCLUSIONS

Oral antifungal agents are associated with low incidence of acute liver injury, but which may be fatal, especially for the elderly. Longer treatment duration may increase the risk of antifungal agent-induced liver injury, especially ketoconazole.

Itraconazole-induced cholestasis: involvement of the inhibition of bile canalicular phospholipid translocator MDR3/ABCB4

Biliary secretion of bile acids and phospholipids, both of which are essential components of biliary micelles, are mediated by the bile salt export pump (BSEP/ABCB11) and multidrug resistance 3 P-glycoprotein (MDR3/ABCB4), respectively, and their genetic dysfunction leads to the acquisition of severe cholestatic diseases. In the present study, we found two patients with itraconazole (ITZ)-induced cholestatic liver injury with markedly high serum ITZ concentrations. To characterize the effect of ITZ on bile formation in vivo, biliary bile acids and phospholipids were analyzed in ITZ-treated rats, and it was revealed that biliary phospholipids, rather than bile acids, were drastically reduced in the presence of clinically relevant concentrations of ITZ. Moreover, by using MDR3-expressing LLC-PK1 cells, we found that MDR3-mediated efflux of [¹⁴C]phosphatidylcholine was significantly reduced by ITZ. In contrast, BSEP-mediated transport of [³H]taurocholate was not significantly affected by ITZ, which is consistent with our in vivo observations. In conclusion, this study suggests the involvement of the inhibition of MDR3-mediated biliary phospholipids secretion in ITZ-induced cholestasis. Our approach may be useful for analyzing mechanisms of drug-induced cholestasis and evaluating the cholestatic potential of clinically used drugs and drug candidates.

Influence of pH on transungual passive and iontophoretic transport

The present study investigated the effects of pH on nail permeability and the transport of ions such as sodium (Na) and chloride (Cl) ions endogenous to nail and hydronium and hydroxide ions present at low and high pH, which might compete with drug transport across hydrated nail plate during iontophoresis. Nail hydration and passive transport of water across the nail at pH 1-13 were assessed. Subsequently, passive and iontophoretic transport experiments were conducted using (22)Na and (36)Cl ions under various pH conditions. Nail hydration was independent of pH under moderate pH conditions and increased significantly under extreme pH conditions (pH >11). Likewise, nail permeability for water was pH independent at pH 1-10 and an order of magnitude higher at pH 13. The results of passive and iontophoretic transport of Na and Cl ions are consistent with the permselective property of nail. Interestingly, extremely acidic conditions (e.g., pH 1) altered nail permselectivity with the effect lasting several days at the higher pH conditions. Hydronium and hydroxide ion competition in iontophoretic transport was generally negligible at pH 3-11 was significant at the extreme pH conditions studied.

Effects of ionic strength on passive and iontophoretic transport of cationic permeant across human nail

PURPOSE

Transport across the human nail under hydration can be modeled as hindered transport across aqueous pore pathways. As such, nail permselectivity to charged species can be manipulated by changing the ionic strength of the system in transungual delivery to treat nail diseases. The present study investigated the effects of ionic strength upon transungual passive and iontophoretic transport.

METHODS

Transungual passive and anodal iontophoretic transport experiments of tetraethylammonium ion (TEA) were conducted under symmetric conditions in which the donor and receiver had the same ionic strength in vitro. Experiments under asymmetric conditions were performed to mimic the in vivo conditions. Prior to the transport studies, TEA uptake studies were performed to assess the partitioning of TEA into the nail.

RESULTS

Permselectivity towards TEA was inversely related to ionic strength in both passive and iontophoretic transport. The permeability and transference number of TEA were higher at lower ionic strengths under the symmetric conditions due to increased partitioning of TEA into the nail. Transference numbers were smaller under the asymmetric conditions compared with their symmetric counterparts.

CONCLUSIONS

The results demonstrate significant ionic strength effects upon the partitioning and transport of a cationic permeant in transungual transport, which may be instrumental in the development of transungual delivery systems.

Drug-related hepatotoxicity and acute liver failure

Drug-induced acute liver failure (ALF) accounts for approximately 20% of ALF in children and a higher percentage of ALF in adults. Although most patients experience milder drug hepatotoxic reactions such as hepatitis, cholestasis, or asymptomatic enzyme elevation, it is important to recognize the potential for progression to ALF. The most common cause of drug-induced ALF in children is acetaminophen (15% of all ALF in children in the United Kingdom and the United States), whereas other drugs such as antituberculous and antiepileptic therapy account for 5%. The pathogenesis of liver injury includes direct hepatotoxicity and idiosyncratic reactions for most drugs, although for others the mechanism of injury is assumed on the basis of clinical presentation and hepatic histological findings. We review the adult and pediatric literature of drug-induced hepatotoxicity and ALF, with special attention to commonly used or offending medications, mechanism of the toxicity, clinical presentation, diagnosis, treatment, and prognosis. Although most of the available information is based on experience in adult patients, we have included that which is applicable to children, or we have cited pediatric examples. Enhanced awareness of the potential hepatotoxicity of commonly prescribed medications may minimize the frequency of serious hepatotoxicity and ALF in pediatric patients.

Fatal Hepatitis After Long-Term Pulse Itraconazole Treatment for Onychomycosis

Objective:

To report the occurrence of acute cytolytic hepatitis In a patient exposed to pulse itraconazole therapy for 24 weeks and provide a concise review of the literature on cases of itraconazole-induced hepatitis.

Case Summary:

A 61 -year-old woman with no apparent risk factors for liver injury developed acute hepatitis one week after the final dose of a long-term course of pulse itraconazole therapy (200 mg orally twice daily, 1 wk on, 3 wk off, for 24 wk) for onychomycosis. Monitoring of liver enzymes was not performed during the treatment period. Serologic evaluations on presentation ruled out Infectious diseases or other etiological factors. Liver function tests showed alanine aminotransferase 3330 U/L, aspartate aminotransferase 3250 U/L, and bilirubin 21 mg/dL Liver function continued to deteriorate, and the patient underwent liver transplantation 17 days after admission. Her liver displayed reduced volume and them was a mild accumulation of ascitic fluid in the retroperitoneal cavity. Histologic evaluation showed massive panlobular necrosis. Complications occurred after transplantation and a rejection crisis worsened the clinical picture until the patient died about 4 months later. Use of the Naranjo probability scale showed the relationship of itraconazole therapy and the occurrence of acute hepatitis as probable.

Discussion:

Itraconazole pulse therapy for onychomycosis appears to be at least as effective as and safer than a continuous treatment regimen, particularly from the perspective of potential liver damage. Only one case of severe symptomatic hepatitis occurring after pulse therapy with itraconazole for onychomycosis and requiring transplantation has been reported previously. In that case, as well as the one reported here, hepatitis symptoms occurred after completion of long-term treatment in patients who were asymptomatic both before and during therapy.

Conclusions:

Prolonged exposure to itraconazole, administered either continuously or intermittently, may precipitate severe and irreversible hepatotoxic events. Accordingly, careful monitoring of liver function parameters should be performed both during and after treatment when onychomycosis requires prolonged itraconazole administration, even in asymptomatic patients lacking apparent risk factors of hepatic injury.