Itraconazole: An Antifungal Drug With Anti Cancer Properties

Background:

Itraconazole is a FDA approved drug, developed as an orally administrated antifungal drug, and has been used clinically for many decades with a well-established safety record. It has been used in the prevention and treatment of a broad range of fungal infections, such as aspergillosis, blastomycosis, candidiasis, histoplasmosis, but also in various dermatological and nail infections.

Since relatively recently, Itraonazole has been identified as a drug with high potential to fight cancer. As it will be discussed below, some of the main mechanism related to this anti tumor action are inhibition of angiogenesis but also the inhibition of Hedgehog pathway. Both mechanism are related to most types of tumors and as a result Itraconazole may be relevant for most types of cancers.

The angiogenesis is relevant for most tumors as without blood vessels, a tumor cannot grow larger than about 1–2 mm in diameter. This seems to be the largest size at which nutrients can permeate by diffusion alone (Ref.). In order to grow further, tumors have to also grow continuously and fast blood vessels, a process which is called angiogenesis.

fungusThe inner lining of all blood vessels consists out of endothelial cells and these cells represents an essential part of new as well as preexisting blood vessels. The proliferation, migration, and differentiation of endothelial cells are integral parts of angiogenesis. In 2007, following a screen of a clinical drug library an unexpected hit indicated Itraconazole as an inhibitor of endothelial cell proliferation and thus acting as an angiogenesis inhibitor.

In this screen itraconazole was unique among other drugs tested in its ability to selectively inhibit the proliferation of endothelial cells with high potency. In sharp contrast to itraconazole, the structurally related terconazole and ketoconazole were 27- and 40-fold less potent (Ref.) Fortunately, the IC50 value of itraconazole used in these experiments was well below the steady state levels achieved with a standard oral 200 mg dose. (Ref.) This means that it is enough to use normal doses of the drug in order to reach the anticancer effects.

The upregulation of Hedgehog pathway in cancer is believed to lead to transformation of adult stem cells into cancer stem cells that give rise to the tumor.

As an inhibitor of angiogenesis and Hedgehog pathway, Itraconazole should lead to both inhibition of tumor growth and metastasis. The inhibition of these mechanisms are expected to take place at drug doses normally used in humans for anti fungal treatments. Indeed, as discussed below there are already a few case reports published where Itraconazole has been shown to induce tumor size reduction in e.g. pancreatic cancer and prostate cancer. However, there are multiple reports in literature indicating its relevance for most tipes of cancers including but not limited to

  • prostate (Ref.),
  • lung (Ref.),
  • basal cell carcinoma (Ref.),
  • ovarian (Ref.),
  • breast – triple negative(Ref.),
  • adrenal (Ref.),
  • brain (Ref.),
  • pancreatic(Ref.),
  • biliary tract cancer (Ref.),
  • etc.

Note that the AnticancerFund foundation has published recently a comprehensive article dedicated to the anti cancer action of Itraconazole (Ref.).

Based on all the scientific evidence, including case reports and clinical trials, Itraconazole is a highly relevant anti cancer drug, accessible to all at a low cost. Best is to combine with other anti cancer drugs. I would probably combine it with other angiogenesis inhibitors to enhance the anti angiogenesis effect or with anti cholesterol drugs and supplements (such as HCA, ACAT inhibitors, Statins). Clinical trials are using Itraconazole both as stand alone therapy or combination with chemo (e.g. Ref.)

Case Report in Humans:

Itraconazole therapy in a pancreatic adenocarcinoma patient: A case report. http://www.ncbi.nlm.nih.gov/pubmed/25670260

This report refers to a 64-year-old male was diagnosed with Stage III locally advanced unresectable pancreatic adenocarcinoma. The patient was treated with radiation plus chemotherapy, which included cisplatin and capecitabine but the patient’s tumor remained unresectable; therefore, palliative chemotherapy treatments were initiated, which included gemcitabine and erlotinib. After two gemcitabine cycles, he was admitted to the hospital because of loss of motor function due to spinal cord hemisection. After the surgery, the patient became neutropenic because of previous chemotherapy cycle and developed disseminated histoplasmosis (infection by a fungus). After he received his nine-month course of itraconazole to address the fungus infection, the pancreatic cancer was readdressed and found to be resectable. The tumor was resected and over the next several years, he showed no evidence of pancreatic metastases or relapse. The treating physicians assessed that the reduction in pancreatic tumour and inhibition of metastasis was due to itraconazole treatment.

Successful treatment of oral itraconazole for infantile hemangiomas: A case series http://onlinelibrary.wiley.com/doi/10.1111/1346-8138.12724/full

Infantile hemangiomas can present a therapeutic challenge to clinicians, especially when associated with severe pain and feeding difficulties. The standard therapeutic management includes corticosteroids and propranolol. However, the clinical response is not always satisfactory. We present six cases of infantile hemangiomas successfully treated with oral itraconazole approximately 5 mg/kg per day. In the first month, the red color of the lesions became a little lighter and the growth of the lesions was controlled in all cases. An obvious clinical improvement was noted in all cases during the 3-month period, with 80–100% improvement in each patient at the end of the treatment, which was judged by both their parents and the dermatologists. Compliance with treatment instructions of oral itraconazole in infants was judged to be very good. Side-effects were mild and limited. Although itraconazole can inhibit angiogenesis and tumor growthin vitro and in vivo associated with some cancers, further research is required to understand the pathogenesis of infantile hemangiomas and the mechanism of itraconazole.

High-dose itraconazole as a non-castrating therapy for a patient with biochemically-recurrent prostate cancer http://europepmc.org/articles/PMC3959234/

A 65-year-old man presented with biochemical recurrence of prostate cancer. … he was referred to our institution for non-hormonal management of his biochemically-recurrent prostate cancer, at which time his PSA was 34.3 ng/mL and his PSADT was about 6 months. Due to the patient’s strong desire to avoid castrating therapies, he requested to be treated off-study with high-dose itraconazole based on the results of the prior phase II trial, while he voiced understanding that this study was conducted in a different patient population and that the results may not apply to his current disease state.

At initiation of treatment with itraconazole (300 mg, twice daily), the patient’s PSA level was 34.3 ng/mL and his testosterone level was in the non-castrate range. Given the potential concern for itraconazole-mediated suppression of adrenal cortical function, aldosterone and cortisol levels were also evaluated as were ACTH levels. Following only one month of treatment with itraconazole, the PSA declined to 20.1 ng/mL, while the patient did report some grade-1 fatigue. After three months of treatment, his PSA had declined to 16.2 ng/mL, reflecting a >50% PSA reduction. Importantly, his testosterone levels remained largely unchanged, while DHEA levels increased somewhat. The patient had no clinical or biochemical evidence of adrenal insufficiency or hypocortisolism. Conversely, he developed hypoaldosteronism accompanied by an elevation in ACTH, consistent with the experience from the prior phase II study. After 5 months of treatment, and despite a persistent PSA response with minimal adverse events, the patient developed asymptomatic hyperbilirubinemia necessitating discontinuation of itraconazole. While the bilirubin level normalized after stopping itraconazole, this was accompanied by a subsequent increase in PSA level to 29.4 ng/mL, approximately one month after drug discontinuation. Due to the occurrence of hyperbilirubinemia, further treatment with high-dose itraconazole was discouraged.

Conclusion: In this patient with biochemically-recurrent prostate cancer, off-label treatment with itraconazole (600 mg/day) resulted in a >50% decline in PSA, without evidence of testosterone suppression.

Clinical Trials:

Combination Chemotherapy with Itraconazole for Treating Metastatic Pancreatic Cancer in the Second-line or Additional Setting. http://www.ncbi.nlm.nih.gov/pubmed/26124377

BACKGROUND: We evaluated chemotherapy with itraconazole (a common anti-fungal agent that is a potent inhibitor of the Hedgehog pathway, P-glycoprotein, and angiogenesis) for treating progressive pancreatic cancer.

PATIENTS AND METHODS: We retrospectively reviewed the medical charts of patients with histologically-diagnosed pancreatic cancer who had received first- or second-line chemotherapy and subsequent chemotherapy with itraconazole.

RESULTS: A total of 38 patients received docetaxel (35 mg/m(2)), gemcitabine (1,000 mg/m(2)), and carboplatin (area under the curve, 4 mg/min/ml) on day 1 and oral itraconazole solution (400 mg) on days -2 to 2, repeated every 2 weeks. One complete response and 13 partial responses were observed, for a response rate of 37%. Eight (21%) patients experienced febrile neutropenia. The median overall survival was 11.4 months (95% confidence interval=8.5-21.2 months).

CONCLUSION: Combination chemotherapy with itraconazole is promising for prolonging overall survival, with acceptable toxicities in the second-line setting of pancreatic cancer.

Impact of Itraconazole After First-line Chemotherapy on Survival of Patients with Metastatic Biliary Tract Cancerhttp://www.ncbi.nlm.nih.gov/pubmed/26254389

AIM: We evaluated the efficacy and safety of itraconazole after first-line chemotherapy in patients with metastatic biliary tract cancer (BTC).
PATIENTS AND METHODS: We retrospectively reviewed data from patients with histologically-diagnosed BTC with distant metastases who had received one or more lines of chemotherapy and subsequent itraconazole chemotherapy.
RESULTS: Among 28 enrolled patients, 26 (93%) received docetaxel (35 mg/m(2)), gemcitabine (1,000 mg/m(2)), and carboplatin (AUC4) on day 1 and oral itraconazole solution (400 mg) on days -2 to 2, repeated every 2 weeks. Two patients received docetaxel plus itraconazole with irinotecan. Two complete responses and 14 partial responses were observed, with a response rate of 57%. The median overall survival was 12.0 months. During 160 cycles, 21 (75%) and 17 (61%) patients had grade 3/4 neutropenia and thrombocytopenia, respectively. Two patients (7%) experienced febrile neutropenia.
CONCLUSION: Combination chemotherapy with itraconazole after first-line chemotherapy is promising for patients with metastatic BTC.

Repurposing Itraconazole as a Treatment for Advanced Prostate Cancer: A Noncomparative Randomized Phase II Trial in Men With Metastatic Castration-Resistant Prostate Cancer http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3579600/

The high-dose arm enrolled to completion (n = 29), but the low-dose arm closed early (n = 17) because of a prespecified futility rule. The PPFS rates at 24 weeks were 11.8% in the low-dose arm and 48.0% in the high-dose arm. The median PFS times were 11.9 weeks and 35.9 weeks, respectively. PSA response rates were 0% and 14.3%, respectively. In addition, itraconazole had favorable effects on CTC counts, and it suppressed Hedgehog signaling in skin biopsy samples. Itraconazole did not reduce serum testosterone or dehydroepiandrostenedione sulfate levels. Common toxicities included fatigue, nausea, anorexia, rash, and a syndrome of hypokalemia, hypertension, and edema. High-dose itraconazole (600 mg/day) has modest antitumor activity in men with metastatic CRPC that is not mediated by testosterone suppression.

Impact of Combination Chemotherapy with Itraconazole on Survival of Patients with Refractory Ovarian Cancer http://ar.iiarjournals.org/content/34/5/2481.abstract

Conclusion: Adjunctive itraconazole is promising for patients with refractory ovarian cancer.

Topical Itraconazole in Treating Patients With Basal Cell Cancer https://clinicaltrials.gov/ct2/show/NCT02735356

A Case Study of the Effects of Topical Itraconazole on Pharmacodynamic Modulation of Hedgehog Target Gene Expression in Basal Cell Carcinomas in Patients

More clinical trials involving Itraconazole are discussed in this reference: Ref.

Mechanism:

Antiangiogenic activity due to inhibition of mTOR.
mTOR inhibition is mediated by:

  • the inhibition of cholesterol trafficking through the endolysosome – cholesterol biosynthesis is also essential for endothelial cell growth.
  • itraconazole binds directly to voltage-dependent anion channel 1 (VDAC1) and interferes with its primary cellular function of regulating mitochondrial metabolism, causing a drop in cellular energy levels that triggers the energy-sensing protein AMP-activated protein kinase (AMPK) which down-regulates mTOR (Ref.)

ultimately leading to inhibition of endothelial cell proliferation and with this antiangiogenic activity.

  • Next to this, it has also be found as a potent inhibitor of Hedgehog (Hh) pathway activity. (Ref.)

Itraconazole mechanisms

The figure above is from Reference: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4081601/figure/F1/

–> Inhibition of cholesterol transport: Cholesterol is an essential component of cellular membranes and plays a key role in membrane permeability and fluidity. Next to this physical role, it also functions in intracellular transport and cell signaling. Cholesterol can be produced in the cell or absorbed from diet into the serum and further delievered within the body. Serum cholesterol is delivered throughout the body in the form of low-density lipoprotein (LDL) and transported into cells via the LDL receptors (through receptor-mediated endocytosis). Endocytosed LDL is transported to the late endosomes and Cholest Transportlysosomes where cholesteryl esters are hydrolyzed and free cholesterol is released from the endosomal system for delivery to other compartments within the cell, including the plasma membrane and endoplasmic reticulum. One of the most important machineries of cholesterol trafficking in the endosomes and lysosomes is the Niemann-Pick, type C (NPC) proteins (NPC1 and NPC2), which help the hydrolysis of cholesteryl esters and deliver free cholesterol out of the endolysosomes. (Ref.) Inhibition of NPC1 or 2 causes accumulation of cholesterol and glycolipids in the endosomes and lysosomes. Itraconazole inhibits cholesterol trafficking and induces accumulation of cholesterols in the organelle (NPC-like phenotype in endothelial cells) and as a result inhibits mTOR activity in endothelial cells and VEGFR2 signaling pathway (Ref.). Thus, interfering with cholesterol trafficking in endothelial cells and that cholesterol trafficking is a novel target for anti-angiogenesis therapy. (Ref.)

The figure above is from Reference: http://atvb.ahajournals.org/content/24/7/1150.full

Here is a very good paper on Cholesterol transport within cells. http://atvb.ahajournals.org/content/24/7/1150.full And here is another good one but older http://www.jbc.org/content/270/26/15443

–> Inhibition of Hedgehog pathway: itraconazole, was identified as a potent inhibitor of Hh pathway activity with an IC50 of approximately 800 nM which is lower than that achieved in humans at normal daily dose (see Pharmacokinetics section) (Ref.) Activation of the hedgehog pathway has been implicated in the development of cancers in various organs, including brain, lung, mammary gland, pancreas, adrenal, prostate and skin. Basal cell carcinoma, the most common form of cancerous malignancy, has the closest association with hedgehog signaling. Abnormal activation of the pathway is believed to lead to development of disease through transformation of adult stem cells into cancer stem cells that give rise to the tumor. Cancer researchers hope that specific inhibitors of hedgehog signaling will provide an efficient therapy for a wide range of malignancies. Drugs that specifically target Hedgehog signaling to fight this disease are being actively developed by a number of pharmaceutical companies (Ref.1, Ref.2).

Note: Imiquimod, previously discussed on this website has also Hedgehog inhibiting properties (Ref.)

Besides the above mechanisms, Itaconazole is also believed to work against multi-drug resistance (MDR) which is highly expressed in many tumors. It is also an autophagy inducer. Itraconazole-induced autophagy is mediated by abnormal cellular cholesterol redistribution and subsequent inhibition of the AKT1-MTOR signaling pathway.  (Ref.1, Ref.2).

Administration and Dose:

Commonly administered orally, either as 100 mg or 200 mg capsules or as oral solution.

Itraconazole is already approved by the U.S. Food and Drug Administration (FDA) as an antifungal agent at oral doses in the range of 200–600 mg/day. This is also the dose range used in clinical trials.  200 mg might be sufficient to inhibit both angiogenesis (Ref.) and Hh pathway (Ref.)

Here is another administration strategy where Itraconazole is combine with Chemo. The strategy seems clever: http://www.ncbi.nlm.nih.gov/pubmed/26124377

I would probably use it in cycles, two weeks on and two weeks off, 200mg 2x/day at 12 hours distance with food.

Antagonists:

I would not combine Itraconazole with autophagy inhibitors (Ref.)

Safety and Toxiciy:

Although itraconazole has been associated with rare cases of hepatotoxicity as its major side effect, it can be taken orally for up to 3 months to treat finger and toenail infections.

In a clinical trial common toxicities included fatigue, abdominal pain, nausea and constipation (Ref.)

Although generally well-tolerated, caution is advised with patients at high risk of heart failure or impaired hepatic function.

Several case reports have identified itraconazole-enhanced chemotherapy toxicity, especially in association with vincaalkaloid chemotherapy. (Ref.)

Coadministration of simvastatin (or lovastatin) with antifungals (itraconazole or ketoconazole) can result in rhabdomyolysis and acute renal failure (Ref.) Simvastatin & lovastatin should therefore not be used concomitantly with itraconazole and other potent CYP3A4 inhibitors, or the dosage of lovastatin should be greatly reduced while using a CYP3A4 inhibitor (Ref.). This increased toxicity is not apparent with fluvastatin (Ref.)

Pharmacokinetics:

  • A single 200 mg dose, taken with food, produces an average peak plasma concentration of 239 ng/mL (0.34μM) within 4.5 hours, whereas at steady state (after 14 days of 200 mg every 12 hours), the average plasma concentration is 1881 ng/mL (2.67 μM).
  • The plasma half-life of 200 mg of the capsule form is 24 hours at steady state.
  • The mean absolute bioavailability is around 55%, and as a highly lipophilic molecule ITZ has a high affinity for tissues, achieving concentrations two to ten times higher than those in plasma.
  • Tissue penetration of antifungals: http://www.ncbi.nlm.nih.gov/pubmed/24396137
  • Oral absorption of itraconazole is reduced when gastric acid production is decreased, by e.g. H2 receptor agonists (such as cimetidine or ranitidine) or proton pump inhibitors (e.g. omeprazole or pantoprazole)
  • is a potent inhibitor of cytochrome P450 (CYP) 3A4 –> check interaction with currently used drugs before administration

Reference for the above points on pharmacokinetics: Ref.

Off target effects:

Low-dose and high-dose itraconazole appeared to slightly increase serum testosterone and DHEA-S levels, respectively. Additionally, high-dose (but not low-dose) itraconazole potently suppressed serum aldosterone while raising plasma ACTH (Ref.1, Ref.2). There were no effects with either itraconazole dose on serum cortisol at 4 weeks or 12 weeks.

Source:

Itraconazole is usually supplied as 100- or 200-mg capsules and can be found at the pharmacy in probably any country, e.g. http://www.buy-pharma.co/Generic-Sporanox-Itraconazole-Capsule-p-194.html

References:

Intracellular Cholesterol Transport http://atvb.ahajournals.org/content/24/7/1150.full

Intracellular cholesterol transport is essential for the maintenance of cholesterol homeostasis. Many aspects of cholesterol metabolism are well-known, including its synthesis in the endoplasmic reticulum, its extracellular transport in plasma lipoproteins, its uptake by the low-density lipoprotein receptor, and its regulation of SREBP and LXR transcription factors. These fundamental pathways in cholesterol metabolism all rely on its proper intracellular distribution among subcellular organelles and the plasma membrane. Transport involving the ER and endosomes is essential for cholesterol synthesis, uptake, and esterification, whereas cholesterol catabolism by enzymes in mitochondria and ER generates steroids, bile acids, and oxysterols. Cholesterol is a highly hydrophobic lipid that requires specialized transport in the aqueous cytosol, involving either vesicles or nonvesicular mechanisms. The latter includes hydrophobic cavity transporters such as StAR-related lipid transfer (START) proteins. Molecular understanding of intracellular cholesterol trafficking has lagged somewhat behind other aspects of cholesterol metabolism, but recent advances have defined some transport pathways and candidate proteins. In this review, we discuss cholesterol transport among specific intracellular compartments, emphasizing the relevance of these pathways to cholesterol homeostasis.

Repurposing Drugs in Oncology (ReDO)—itraconazole as an anti-cancer agent http://ecancer.org/journal/9/full/521-repurposing-drugs-in-oncology-redo-itraconazole-as-an-anti-cancer-agent.php

Itraconazole, a common triazole anti-fungal drug in widespread clinical use, has evidence of clinical activity that is of interest in oncology. There is evidence that at the clinically relevant doses, itraconazole has potent anti-angiogenic activity, and that it can inhibit the Hedgehog signalling pathway and may also induce autophagic growth arrest. The evidence for these anticancer effects, in vitro, in vivo, and clinical are summarised, and the putative mechanisms of their action outlined. Clinical trials have shown that patients with prostate, lung, and basal cell carcinoma have benefited from treatment with itraconazole, and there are additional reports of activity in leukaemia, ovarian, breast, and pancreatic cancers. Given the evidence presented, a case is made that itraconazole warrants further clinical investigation as an anti- cancer agent. Additionally, based on the properties summarised previously, it is proposed that itraconazole may synergise with a range of other drugs to enhance the anti-cancer effect, and some of these possible combinations are presented in the supplementary materials accompanying this paper.

Itraconazole Inhibits Angiogenesis and Tumor Growth in Non–Small Cell Lung Cancer http://cancerres.aacrjournals.org/content/71/21/6764.abstract

The antiangiogenic agent bevacizumab has been approved for the treatment of non–small cell lung cancer (NSCLC), although the survival benefit associated with this agent is marginal, and toxicities and cost are substantial. A recent screen for selective inhibitors of endothelial cell proliferation identified the oral antifungal drug itraconazole as a novel agent with potential antiangiogenic activity. In this article, we define and characterize the antiangiogenic and anticancer activities of itraconazole in relevant preclinical models of angiogenesis and lung cancer. Itraconazole consistently showed potent, specific, and dose-dependent inhibition of endothelial cell proliferation, migration, and tube formation in response to both VEGF- and basic fibroblast growth factor–mediated angiogenic stimulation. In vivo, using primary xenograft models of human NSCLC, oral itraconazole showed single-agent growth-inhibitory activity associated with induction of tumor hypoxia-inducible factor 1 alpha expression and marked inhibition of tumor vascularity. Itraconazole significantly enhanced the antitumor efficacy of the chemotherapeutic agent cisplatin in the same model systems. Taken together, these data suggest that itraconazole has potent and selective inhibitory activity against multiple key aspects of tumor-associated angiogenesis in vitro and in vivo, and strongly support clinical translation of its use. Based on these observations, we have initiated a randomized phase II study comparing the efficacy of standard cytotoxic therapy with or without daily oral itraconazole in patients with recurrent metastatic NSCLC.

Clinical Implications of Hedgehog Pathway Signaling in Prostate Cancer http://www.mdpi.com/2072-6694/7/4/0871/htm

Activity in the Hedgehog pathway, which regulates GLI-mediated transcription, is important in organogenesis and stem cell regulation in self-renewing organs, but is pathologically elevated in many human malignancies. Mutations leading to constitutive activation of the pathway have been implicated in medulloblastoma and basal cell carcinoma, and inhibition of the pathway has demonstrated clinical responses leading to the approval of the Smoothened inhibitor, vismodegib, for the treatment of advanced basal cell carcinoma. Aberrant Hedgehog pathway signaling has also been noted in prostate cancer with evidence suggesting that it may render prostate epithelial cells tumorigenic, drive the epithelial-to-mesenchymal transition, and contribute towards the development of castration-resistance through autocrine and paracrine signaling within the tumor microenvironment and cross-talk with the androgen pathway. In addition, there are emerging clinical data suggesting that inhibition of the Hedgehog pathway may be effective in the treatment of recurrent and metastatic prostate cancer. Here we will review these data and highlight areas of active clinical research as they relate to Hedgehog pathway inhibition in prostate cancer.

Disclaimer:

This site is not designed to and does not provide medical advice, professional diagnosis, opinion, treatment or services to you or to any other individual. Through this site and linkages to other sites, I provide general information for educational purposes only. The information provided in this site, or through linkages to other sites, is not a substitute for medical or professional care, and you should not use the information in place of a visit, call consultation or the advice of your physician or other healthcare provider. I am not liable or responsible for any advice, course of treatment, diagnosis or any other information, services or product you obtain through this site. This is just my own personal opinion regarding what we have learned on this road.

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6 Comments on "Itraconazole: An Antifungal Drug With Anti Cancer Properties"

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ovidiu
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A couple of observations. The usability of itraconazole for brain cancer is highly debatable. The article cited proved that it is effective in vitro and in subcutaneous xenografts, but penetration into CSF (from oral or injectable administration) is poor and variable, so I wouldn’t recommend it for brain cancer. While it has been proposed as a substitute for ketoconazole in the CUSP9 –> CUSP9* protocols, this poor penetration (probably due to the very high protein binding) into CSF seems to have been omitted. Direct delivery of itraconazole into CSF may be effective though, but I found no reference, and there… Read more »
Andreas
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Hello Daniel, is omeprazole autophagy inhibitor ?