Fluconazole-Teva hard capsules 150 mg No. 1

Instructions for Fluconazole-Teva hard capsules 150 mg No. 1

Composition

active ingredient: fluconazole;

1 hard capsule contains 150 mg of fluconazole;

excipients:

capsule contents: lactose monohydrate, corn starch, colloidal anhydrous silica, sodium lauryl sulfate, magnesium stearate;

capsule shell: titanium dioxide (E 171), diamond blue FCF (E 133), gelatin.

Dosage form

The capsules are hard.

Main physicochemical properties: hard gelatin capsules filled with white or yellowish-white homogeneous powder, with an opaque cap and a blue body.

Pharmacotherapeutic group

Antifungal drugs for systemic use, triazole derivatives. ATX code J02A C01.

Pharmacological properties

Pharmacodynamics.

Mechanism of action.

Fluconazole is a triazole antifungal agent. Its primary mechanism of action is inhibition of fungal cytochrome P450-mediated 14-α-lanosterol demethylation, an essential step in fungal ergosterol biosynthesis. Accumulation of 14-α-methyl sterols correlates with subsequent loss of ergosterol from the fungal cell membrane and may be responsible for the antifungal activity of fluconazole. Fluconazole is more selective for fungal cytochrome P450 enzymes than for various mammalian cytochrome P450 enzyme systems.

Fluconazole 50 mg daily for 28 days had no effect on plasma testosterone concentrations in men or steroid concentrations in women of reproductive age. Fluconazole at doses of 200-400 mg daily had no clinically significant effect on endogenous steroid levels or on the response to adrenocorticotropic hormone (ACTH) stimulation in healthy male volunteers.

Interaction studies with antipyrine have shown that single or repeated administration of 50 mg fluconazole does not affect the metabolism of antipyrine.

In vitro sensitivity

In vitro, fluconazole exhibits antifungal activity against most clinically common Candida species (including C. albicans, C. parapsilosis, C. tropicalis). C. glabrata exhibits reduced susceptibility to fluconazole, while C. krusei and C. auris are resistant to fluconazole. The minimum inhibitory concentration (MIC) and epidemiological cut-off value (ECOFF) of fluconazole for C. guilliermondii are higher than for C. albicans.

Fluconazole also exhibits in vitro activity against Cryptococcus neoformans and Cryptococcus gattii, as well as against the endemic fungal forms Blastomyces dermatiditis, Coccidioides immitis, Histoplasma capsulatum and Paracoccidioides brasiliensis.

Relationship between pharmacokinetic and pharmacodynamic properties

Animal studies have shown a correlation between MIC values and efficacy against experimental models of fungal infections caused by Candida species. Clinical studies have shown an almost 1:1 linear relationship between AUC and dose of fluconazole. There is also a direct but weak relationship between AUC or dose and a positive clinical response to treatment of oral candidiasis and, to a lesser extent, candidemia. Treatment is also less effective in infections caused by strains with higher fluconazole MICs.

Mechanism of resistance

Candida species have a number of resistance mechanisms to azole antifungals. Fungal strains that have developed one or more of these resistance mechanisms are known to have high MICs to fluconazole, which adversely affects efficacy in vivo and in the clinical setting.

In normally susceptible Candida species, the most common mechanism of resistance development is related to the azole target enzymes responsible for ergosterol biosynthesis. Resistance may be due to mutation, increased enzyme production, efflux mechanisms, or the development of compensatory pathways.

Superinfection with Candida species other than C. albicans that have naturally reduced susceptibility (C. glabrata) or are resistant to fluconazole (e.g. C. krusei and C. auris) has been reported. Such infections may require alternative antifungal therapy. The mechanisms of resistance have not been fully elucidated in some Candida species with inherent resistance (C. krusei) or new ones (C. auris).

Breakpoints (according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST))

Based on analyses of pharmacokinetic/pharmacodynamic (PK/PD) data, in vitro susceptibility and clinical response, breakpoints for fluconazole against Candida species have been established. These are divided into non-species breakpoints, which were determined primarily on the basis of PK/PD data and are independent of species-specific MIC allocation, and breakpoints related to species most commonly associated with human infections. These breakpoints are listed in the table below:

A - non-species-specific breakpoints were determined primarily on the basis of PK/PD data and are not dependent on species-specific MIC allocation. They are used only for organisms that do not have specific breakpoints;

- – susceptibility testing is not recommended, as this species is not the target of drug therapy;

* – C. glabrata species is classified as Category I. MICs against C. glabrata should be interpreted as resistant if they exceed 16 mg/L. The susceptible category (≤ 0.001 mg/L) is to avoid misclassification of “I” strains as “S” strains. I – Susceptible, increased exposure: An organism is classified as susceptible, increased exposure when there is a high probability of therapeutic success because the exposure of the agent is increased by adjusting the dosage regimen or its concentration at the site of infection.

Pharmacokinetics.

The pharmacokinetic properties of fluconazole are similar after intravenous and oral administration.

Absorption. Fluconazole is well absorbed after oral administration, and plasma levels and systemic bioavailability exceed 90% of those achieved after intravenous administration. Concomitant food intake does not affect oral absorption. Peak plasma concentrations are reached 0.5–1.5 hours after administration on an empty stomach. Plasma concentrations are dose-proportional. Steady-state concentrations of 90% are reached by day 4–5 with multiple once-daily dosing. Steady-state concentrations of 90% are reached by day 2 of treatment with a loading dose of twice the usual daily dose given on the first day.

Distribution: The volume of distribution is approximately equal to the total body fluid content. Plasma protein binding is low (11–12%).

Fluconazole penetrates well into all body fluids tested. Fluconazole levels in saliva and sputum are similar to plasma concentrations. In patients with fungal meningitis, fluconazole levels in cerebrospinal fluid reach 80% of plasma concentrations.

High concentrations of fluconazole in the skin, exceeding serum levels, are achieved in the stratum corneum, epidermis, dermis and eccrine sweat. Fluconazole accumulates in the stratum corneum. When a dose of 50 mg is used once a day, the concentration of fluconazole after 12 days of treatment was 73 μg/g, and 7 days after the end of treatment, the concentration was still 5.8 μg/g. When a dose of 150 mg is used once a week, the concentration of fluconazole in the stratum corneum on the 7th day of treatment was 23.4 μg/g; 7 days after the next dose, the concentration was still 7.1 μg/g.

The concentration of fluconazole in nails after 4 months of 150 mg once weekly administration was 4.05 μg/g in healthy volunteers and 1.8 μg/g in patients with nail diseases; fluconazole was detected in nail samples 6 months after the end of therapy.

Biotransformation. Fluconazole is metabolized to a small extent. When a dose labeled with radioactive isotopes is administered, only 11% of fluconazole is excreted in the urine in an unchanged form. Fluconazole is a moderate inhibitor of the isoenzymes CYP2C9 and CYP3A4, as well as a potent inhibitor of the isoenzyme CYP2C19.

Elimination. The plasma half-life of fluconazole is approximately 30 hours. The majority of the drug is excreted by the kidneys, with 80% of the administered dose being excreted unchanged in the urine. Fluconazole clearance is proportional to creatinine clearance. No circulating metabolites have been identified.

The long half-life of the drug from blood plasma allows for a single use of the drug for vaginal candidiasis, as well as the use of the drug once a week for other indications.

Pharmacokinetics in renal impairment

In patients with severe renal impairment (GFR < 20 ml/min), the elimination half-life is increased from 30 to 98 hours, requiring a corresponding dose reduction. Fluconazole is removed by hemodialysis and, to a lesser extent, by peritoneal dialysis. A 3-hour hemodialysis session reduces the plasma levels of fluconazole by approximately 50%.

Pharmacokinetics during lactation

Fluconazole plasma and breast milk concentrations were evaluated in a pharmacokinetic study involving ten lactating women who had temporarily or permanently discontinued breast-feeding their infants for 48 hours after a single dose of 150 mg fluconazole. Fluconazole was found in breast milk at a mean concentration of approximately 98% of that observed in maternal plasma. The mean peak breast milk concentration was 2.61 mg/L 5.2 hours after dosing. The daily dose of fluconazole received by the infant from breast milk (assuming an average milk intake of 150 ml/kg/day), calculated based on the average peak milk concentration of 0.39 mg/kg/day, is approximately 40% of the dose recommended for newborns (< 2 weeks of age) or 13% of the dose recommended for infants for the treatment of mucosal candidiasis.

Pharmacokinetics in children

After administration of 2–8 mg/kg fluconazole to children aged 9 months to 15 years, the AUC was approximately 38 μg*h/ml per 1 mg/kg dose. With multiple administration, the mean plasma half-life of fluconazole ranged between 15 and 18 hours, and the volume of distribution was approximately 880 ml/kg. A longer plasma half-life of fluconazole was approximately 24 hours and was observed after a single dose. This is comparable to the plasma half-life of fluconazole after a single intravenous dose of 3 mg/kg to children aged 11 days to 11 months. The volume of distribution in this age group was approximately 950 ml/kg.

Experience with fluconazole in neonates is limited to pharmacokinetic studies in 12 premature infants with a gestational age of approximately 28 weeks. The mean age at first dose was 24 hours (range 9–36 hours), and the mean birth weight was 0.9 kg (range 0.75–1.10 kg). Seven patients completed the study protocol. A maximum of 5 intravenous injections of fluconazole at a dose of 6 mg/kg were administered every 72 hours. The mean half-life was 74 hours (44–185) on the first day, then decreased to 53 hours (30–131) on the 7th day and to 47 (27–68) on the 13th day. The area under the curve (μg*h/mL) was 271 (173–385) on day 1, increasing to 490 (292–734) on day 7, then decreasing to 360 (167–566) on day 13. The volume of distribution (mL/kg) was 1183 (1070–1470) on day 1, increasing to 1184 (510–2130) on day 7 and 1328 (1040–1680) on day 13, respectively.

Pharmacokinetics in elderly patients

In a study conducted in 22 patients (aged 65 years and older), fluconazole was administered orally at a dose of 50 mg. 10 patients were receiving concomitant diuretics. Cmax was 1.54 μg/ml and was achieved within 1.3 hours after fluconazole administration. The mean AUC was 76.4 ± 20.3 μg*h/ml. The mean elimination half-life was 46.2 hours. These pharmacokinetic parameters are higher compared to those in healthy young volunteers. Concomitant use of diuretics had no significant effect on Cmax and AUC. Also, creatinine clearance (74 mL/min), percentage of fluconazole excreted unchanged in urine (0–24 hours, 22%), and renal clearance of fluconazole (0.124 mL/min/kg) in patients of this age group were lower than those in younger volunteers. Therefore, changes in pharmacokinetics in elderly patients are likely to be dependent on renal function parameters.

Indication

Acute vaginal candidiasis when topical therapy is not appropriate.

Candidal balanitis when topical therapy is not appropriate.

Contraindication

Hypersensitivity to fluconazole, to other azole substances or to any of the excipients of the drug;

Concomitant use of fluconazole with terfenadine is contraindicated in patients taking fluconazole multiple times at doses of 400 mg per day or higher (based on the results of multiple-dose interaction studies);

Concomitant use of fluconazole with other drugs that prolong the QT interval and are metabolized by the CYP3A4 enzyme (e.g. cisapride, astemizole, pimozide, quinidine and erythromycin), see also sections "Special warnings and precautions for use" and "Interaction with other medicinal products and other forms of interaction".

Interaction with other medicinal products and other types of interactions

Concomitant use with the following drugs is contraindicated:

Cisapride. Cardiac events such as torsades de pointes have been reported in patients receiving fluconazole and cisapride concomitantly. In a controlled study, concomitant administration of fluconazole 200 mg once daily and cisapride 20 mg four times daily resulted in significant increases in plasma cisapride levels and prolongation of the QTc interval. Concomitant treatment with fluconazole and cisapride is contraindicated (see section 4.3).

Terfenadine. Due to cases of serious cardiac arrhythmias caused by prolongation of the QTc interval, drug-drug interaction studies have been performed in patients receiving azole antifungals concomitantly with terfenadine. A study with fluconazole 200 mg/day did not demonstrate prolongation of the QTc interval. Another study with fluconazole 400 mg/day and 800 mg/day showed that fluconazole, when administered at a dose of 400 mg/day or higher, significantly increased plasma levels of terfenadine when administered concomitantly. Concomitant use of fluconazole at doses of 400 mg/day or higher with terfenadine is contraindicated (see section 4.3). Careful monitoring of the patient's condition is recommended when fluconazole is administered concomitantly with terfenadine at doses below 400 mg/day.

Pimozide. Concomitant use of fluconazole with pimozide may result in inhibition of pimozide metabolism, although in vitro and in vivo studies have not been conducted. Increased plasma concentrations of pimozide may lead to QT prolongation and, in rare cases, torsades de pointes. Concomitant use of fluconazole with pimozide is contraindicated (see section 4.3).

Quinidine. Concomitant use of fluconazole and quinidine may result in inhibition of quinidine metabolism, although in vitro and in vivo studies have not been conducted. Quinidine has been associated with QT prolongation and, in rare cases, paroxysmal torsades de pointes. Concomitant use of fluconazole and quinidine is contraindicated (see section 4.3).

Erythromycin. Concomitant use of fluconazole with erythromycin may lead to an increased risk of cardiotoxicity (QT prolongation and torsades de pointes) and, as a result, sudden coronary death. Concomitant use of fluconazole and erythromycin is contraindicated (see section "Contraindications").

Concomitant use with the following medicines is not recommended:

Halofantrine. Fluconazole may increase the plasma concentration of halofantrine due to inhibition of CYP3A4. Concomitant use of fluconazole and halofantrine may increase the risk of cardiotoxicity (QT prolongation, torsades de pointes) and, as a result, sudden coronary death. The use of this combination should be avoided (see section 4.4).

Concomitant use of fluconazole and the following drugs requires caution:

Amiodarone: Concomitant use of fluconazole with amiodarone may prolong the QT interval. Fluconazole, especially at high doses (800 mg), should be used with caution with amiodarone.

Concomitant use of fluconazole with the following drugs requires caution and dose adjustment:

Effects of other drugs on fluconazole

Interaction studies have shown that oral administration of fluconazole with food, cimetidine, antacids, or subsequent systemic irradiation for bone marrow transplantation has no clinically significant effect on the absorption of fluconazole.

Rifampicin: Concomitant administration of fluconazole and rifampicin resulted in a 25% decrease in AUC and a 20% decrease in the half-life of fluconazole. Therefore, an increase in the dose of fluconazole should be considered in patients taking rifampicin.

Hydrochlorothiazide: In a pharmacokinetic interaction study, co-administration of multiple hydrochlorothiazide to healthy volunteers receiving fluconazole increased the plasma concentrations of fluconazole by 40%. These interaction parameters do not require changes in the dosing regimen of fluconazole in patients receiving concomitant diuretics.

Effect of fluconazole on other drugs

Fluconazole is a moderate inhibitor of cytochrome P450 (CYP) isoenzymes 2C9 and 3A4. Fluconazole is a potent inhibitor of the CYP2C19 isoenzyme. In addition to these types of interactions that have been observed or documented, there is a risk of increased concentrations of other compounds that are metabolized by CYP2C9, CYP2C19 and CYP3A4 when used concomitantly with fluconazole. Therefore, caution should be exercised when using these combinations and the patient should be closely monitored. The inhibitory effect of fluconazole on the enzymes persists for 4-5 days after discontinuation of its use due to its long half-life.

Alfentanil: When fluconazole (400 mg) was co-administered with intravenous alfentanil (20 mcg/kg) in healthy volunteers, the AUC10 of alfentanil increased two-fold, possibly due to inhibition of CYP3A4. Dose adjustment of alfentanil may be necessary.

Amitriptyline, nortriptyline. Fluconazole potentiates the effects of amitriptyline and nortriptyline. It is recommended to measure 5-nortriptyline and/or S-amitriptyline at the beginning of combination therapy and after 1 week. If necessary, the dose of amitriptyline/nortriptyline should be adjusted.

Anticoagulants: As with other azole antifungals, bleeding events (bruising, epistaxis, gastrointestinal bleeding, hematuria, and melena) associated with increased prothrombin time have been reported in postmarketing experience in patients receiving fluconazole concomitantly with warfarin. A two-fold increase in prothrombin time has been observed when fluconazole and warfarin are coadministered, possibly due to inhibition of warfarin metabolism by CYP2C9. Patients receiving coumarin-type or indandione anticoagulants concomitantly with fluconazole should have their prothrombin time closely monitored. Dosage adjustment of the anticoagulant may be necessary.

Short-acting benzodiazepines, e.g. midazolam, triazolam. Administration of fluconazole after oral midazolam resulted in a significant increase in midazolam concentrations and increased psychomotor effects. Concomitant administration of fluconazole 200 mg and midazolam 7.5 mg orally resulted in a 3.7- and 2.2-fold increase in AUC and half-life, respectively. Administration of fluconazole 200 mg/day and triazolam 0.25 mg orally resulted in a 4.4- and 2.3-fold increase in AUC and half-life, respectively. Potentiation and prolongation of the effects of triazolam were observed with concomitant administration of fluconazole and triazolam.

If a patient undergoing treatment with fluconazole is to be prescribed concomitant therapy with benzodiazepines, the dose of the latter should be reduced and appropriate monitoring of the patient's condition should be established.

Carbamazepine. Fluconazole inhibits the metabolism of carbamazepine and causes a 30% increase in serum carbamazepine levels. There is a risk of carbamazepine toxicity. The dose of carbamazepine may need to be adjusted depending on its concentration and effect.

Calcium channel blockers. Some calcium antagonists (nifedipine, isradipine, amlodipine, verapamil, and felodipine) are metabolized by the CYP3A4 enzyme. Fluconazole has the potential to increase systemic exposure to calcium channel blockers. Close monitoring for adverse reactions is recommended.

Celecoxib: Concomitant administration of fluconazole (200 mg daily) and celecoxib (200 mg) increased celecoxib Cmax and AUC by 68% and 134%, respectively. A halving of the celecoxib dose may be necessary when celecoxib and fluconazole are coadministered.

Cyclophosphamide: Concomitant use of cyclophosphamide and fluconazole has been shown to increase serum bilirubin and creatinine levels. These drugs may be used concomitantly, given the risk of increased serum bilirubin and creatinine concentrations.

Fentanyl. One fatal case of fentanyl intoxication has been reported due to a possible interaction between fentanyl and fluconazole. In addition, a study in healthy volunteers showed that fluconazole significantly delayed the elimination of fentanyl. Increased fentanyl concentrations may lead to respiratory depression, so the patient should be closely monitored. Fentanyl dosage adjustment may be necessary.

HMG-CoA reductase inhibitors. Concomitant use of fluconazole and HMG-CoA reductase inhibitors metabolized by CYP3A4 (atorvastatin and simvastatin) or HMG-CoA reductase inhibitors metabolized by CYP2C9 (fluvastatin) increases the risk of myopathy and rhabdomyolysis. If concomitant use of these drugs is necessary, the patient should be closely observed for symptoms of myopathy and rhabdomyolysis and creatine kinase levels should be monitored. In the event of a significant increase in creatine kinase levels, as well as when myopathy/rhabdomyolysis is diagnosed or suspected, the use of HMG-CoA reductase inhibitors should be discontinued.

Ibritinib: Moderate CYP3A4 inhibitors, such as fluconazole, increase ibritinib plasma concentrations and may increase the risk of toxicity. If the combination cannot be avoided, the ibritinib dose should be reduced to 280 mg once daily (2 capsules) to maintain inhibitor use and ensure ongoing clinical monitoring.

Ivacaftor: Co-administration of ivacaftor, a cystic fibrosis transmembrane conductance regulator (CFTR), increased ivacaftor exposure 3-fold and hydroxymethylivacaftor (M1) exposure 1.9-fold. It is recommended that patients taking moderate CYP3A inhibitors such as fluconazole and erythromycin be given ivacaftor at a dose of 150 mg once daily.

Olaparib: Moderate CYP3A4 inhibitors, such as fluconazole, increase olaparib plasma concentrations; concomitant use is not recommended. If the combination cannot be avoided, olaparib should be limited to 200 mg twice daily.

Immunosuppressants (e.g. cyclosporine, everolimus, sirolimus and tacrolimus)

Cyclosporine. Fluconazole significantly increases the concentration and AUC of cyclosporine. With simultaneous use of fluconazole at a dose of 200 mg/day and cyclosporine at a dose of 2.7 mg/kg/day, an increase in the AUC of cyclosporine by 1.8 times was observed. These drugs can be used simultaneously, provided that the dose of cyclosporine is reduced depending on its concentration.

Sirolimus: Fluconazole increases plasma concentrations of sirolimus, possibly by inhibiting sirolimus metabolism by CYP3A4 and P-glycoprotein. These drugs can be used concomitantly, with dose adjustments of sirolimus based on drug levels and effects.

Tacrolimus: Fluconazole may increase the serum concentrations of tacrolimus up to 5-fold when administered orally due to inhibition of tacrolimus metabolism by the CYP3A4 enzyme in the intestine. No significant changes in pharmacokinetics have been observed with intravenous administration of tacrolimus. Elevated tacrolimus levels are associated with nephrotoxicity. The oral dose of tacrolimus should be reduced depending on tacrolimus concentrations.

Losartan: Fluconazole inhibits the metabolism of losartan to its active metabolite (E-31 74), which accounts for most of the angiotensin II receptor antagonism during the use of losartan. Continuous monitoring of blood pressure in patients is recommended.

Methadone: Fluconazole may increase the serum concentration of methadone. Methadone dosage adjustment may be necessary when methadone and fluconazole are used concomitantly.

Non-steroidal anti-inflammatory drugs (NSAIDs). When co-administered with fluconazole, the Cmax and AUC of flurbiprofen increased by 23% and 81%, respectively, compared to flurbiprofen alone. Similarly, when co-administered with racemic ibuprofen (400 mg), the Cmax and AUC of the pharmacologically active isomer S-(+)-ibuprofen increased by 15% and 82%, respectively, compared to racemic ibuprofen alone.

Although no specific studies have been conducted, fluconazole has the potential to increase the systemic exposure of other NSAIDs metabolized by CYP2C9 (e.g. naproxen, lornoxicam, meloxicam, diclofenac). Periodic monitoring for adverse reactions and toxicities associated with NSAIDs is recommended. Dose adjustment of the NSAID may be necessary.

Phenytoin. Fluconazole inhibits the metabolism of phenytoin in the liver. Simultaneous multiple administration of 200 mg of fluconazole and 250 mg of phenytoin intravenously leads to an increase in phenytoin AUC24 by 75% and Cmin by 128%. When these drugs are used simultaneously, phenytoin serum concentrations should be monitored to avoid the development of phenytoin toxicity.

Prednisone. A case report has been made of a liver transplant patient receiving prednisone who developed acute adrenal insufficiency after discontinuation of a three-month course of fluconazole. Discontinuation of fluconazole is likely to have resulted in increased CYP3A4 activity, leading to increased metabolism of prednisone. Patients receiving long-term concomitant fluconazole and prednisone should be carefully monitored for the development of adrenal insufficiency after discontinuation of fluconazole.

Rifabutin. Fluconazole increases the serum concentration of rifabutin, leading to an increase in the AUC of rifabutin by up to 80%. Cases of uveitis have been reported with the concomitant use of fluconazole and rifabutin. Symptoms of rifabutin toxicity should be considered when using this combination of drugs.

Saquinavir: Fluconazole increases the AUC and Cmax of saquinavir by approximately 50% and 55%, respectively, due to inhibition of the hepatic metabolism of saquinavir by CYP3A4 and inhibition of P-glycoprotein. Interactions between fluconazole and saquinavir/ritonavir have not been studied and may be more severe. Saquinavir dose adjustment may be necessary.

Sulfonylureas: Concomitant use of fluconazole prolongs the half-life of oral sulfonylureas (chlorpropamide, glibenclamide, glipizide, and tolbutamide) in healthy volunteers. Frequent monitoring of blood glucose levels and appropriate dose reduction of sulfonylureas is recommended when co-administered with fluconazole.

Theophylline. In a placebo-controlled study of the interaction of fluconazole and theophylline, it was found that the use of fluconazole 200 mg for 14 days resulted in an 18% decrease in the mean plasma clearance of theophylline. Patients receiving high doses of theophylline or who are at increased risk of theophylline toxicity for other reasons should be monitored for signs of theophylline toxicity. Therapy should be changed if signs of toxicity appear.

Tolvaptan: Tolvaptan exposure is significantly increased (200% AUC; 80% Cmax) when tolvaptan, a CYP3A4 substrate, is co-administered with fluconazole, a moderate CYP3A4 inhibitor, increasing the risk of adverse reactions, particularly significant diuresis, dehydration, and acute renal failure. In case of co-administration, the tolvaptan dose should be reduced according to the prescribing information, and the patient should be monitored frequently for any adverse reactions related to tolvaptan.

Vinca alkaloids: Although not studied, fluconazole, possibly through inhibition of CYP3A4, may increase plasma concentrations of vinca alkaloids (e.g. vincristine and vinblastine), leading to neurotoxic effects.

Vitamin A. A patient receiving all-trans retinoic acid (the acid form of vitamin A) and fluconazole was reported to have a CNS-related pseudotumor cerebri effect; this effect resolved after discontinuation of fluconazole. These drugs can be used concomitantly, but the risk of CNS-related side effects should be considered.

Voriconazole (CYP2C9, CYP2C19, and CYP3A4 inhibitor). Coadministration of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 2.5 days) and oral fluconazole (400 mg on day 1, then 200 mg every 24 hours for 4 days) to 8 healthy male volunteers resulted in an average increase in voriconazole Cmax and AUCτ of 57% (90% CI: 20%, 107%) and 79% (90% CI: 40%, 128%), respectively. It is unknown whether reducing the dose and/or frequency of voriconazole or fluconazole would eliminate this effect. When voriconazole is administered after fluconazole, monitoring for adverse events associated with voriconazole should be performed.

Zidovudine. Fluconazole increased the Cmax and AUC of zidovudine by 84% and 74%, respectively, due to a decrease in zidovudine clearance by approximately 45% when administered orally. The half-life of zidovudine was also prolonged by approximately 128% after the combination of fluconazole and zidovudine. Patients receiving this combination should be monitored for adverse reactions associated with zidovudine. A reduction in the dose of zidovudine may be considered.

Azithromycin: In an open-label, randomized, three-way crossover study in 18 healthy volunteers, the effects of azithromycin and fluconazole on the pharmacokinetics of each other were evaluated when administered orally at single doses of 1200 mg and 800 mg, respectively. No significant pharmacokinetic interactions were observed.

Oral contraceptives. From two pharmacokinetic studies of multiple administration of fluconazole and a combined oral contraceptive, it is known that when fluconazole was used at a dose of 50 mg, there was no effect on hormone levels, while when fluconazole was used at a dose of 200 mg per day, an increase in the AUC of ethinylestradiol by 40% and levonorgestrel by 24% was observed. This indicates that multiple administration of fluconazole at these doses is unlikely to affect the efficacy of a combined oral contraceptive.

Physicians should note that drug interaction studies have not been conducted, but such interactions may occur.

Application features

Ringworm: A study of fluconazole for the treatment of ringworm in children found that fluconazole was not superior to griseofulvin in efficacy and the overall efficacy rate was less than 20%. Therefore, fluconazole should not be used for the treatment of ringworm.

Cryptococcosis. There is insufficient evidence of fluconazole efficacy in the treatment of cryptococcosis of other sites (e.g., pulmonary cryptococcosis and cutaneous cryptococcosis), and therefore no dosage recommendations can be made for these conditions.

Deep endemic mycoses. Evidence of the effectiveness of fluconazole for the treatment of other forms of endemic mycoses, such as paracoccidioidomycosis, histoplasmosis and cutaneous lymphocytic sporotrichosis, is insufficient, therefore there are no recommendations for a dosage regimen for the treatment of such diseases.

Candidiasis. Studies have shown an increase in the prevalence of infections caused by Candida species other than C. albicans. These are often resistant in nature (e.g. C. krusei and C. auris) or have proliferative properties.