ITRAZOL 100/MG CAP 4/CAP

Indications

Approved Uses

Treatment of susceptible fungal infections including: aspergillosis, blastomycosis, histoplasmosis, and onychomycosis; mucosal candidiasis (e.g., oropharyngeal and esophageal) is also an approved use in many regulators/labels.

Off-Label Uses

Examples of off-label uses include: coccidioidomycosis, paracoccidioidomycosis, sporotrichosis (depending on local labeling), chromoblastomycosis, and antifungal prophylaxis in selected immunocompromised patients when alternatives are unsuitable.

Dosage & Administration

Dosing by Condition

Onychomycosis: Toenail-200 mg once daily for 12 weeks OR pulse 200 mg twice daily for 1 week repeated every 4 weeks for 3 pulses; Fingernail-pulse 200 mg twice daily for 1 week repeated every 4 weeks for 2 pulses. Oropharyngeal candidiasis-200 mg/day (often 200 mg once daily) for 1-2 weeks (up to 2 weeks). Esophageal candidiasis-200 mg/day (may increase to 200 mg twice daily) for at least 3 weeks and for 2 weeks after symptom resolution. Aspergillosis-200 mg once or twice daily (up to 400 mg/day) for months depending on response. Histoplasmosis/Blastomycosis-typically 200 mg once or twice daily (up to 400 mg/day) for prolonged durations (often months).

Initial Dose

100-200 mg once daily depending on indication

Maintenance Dose

100-200 mg once or twice daily depending on indication and severity

Maximum Dose

400 mg per day for capsules, though up to 600 mg/day has been used under specialist supervision for severe infections.

Children's Dosage

Not routinely approved for children; limited data available. When used in life-threatening situations: 5 mg/kg/day has been used under specialist supervision

Dose Adjustment Notes

No routine renal dose adjustment, but use caution (especially in severe renal impairment) due to variable absorption/exposure; in hepatic impairment use caution and consider dose reduction/monitoring as exposure may increase and hepatotoxicity risk is higher. Note: capsules with food; oral solution (if used) has higher bioavailability and is taken on an empty stomach.

How to Take

Swallow capsules whole immediately after a full meal; do not crush or chew. If gastric acidity is reduced (e.g., PPIs/H2 blockers/antacids, achlorhydria), avoid acid-suppressants if possible or take the capsule with an acidic beverage (e.g., non-diet cola) and separate antacids by at least 2 hours.

Side Effects

Common Side Effects

Common: nausea, vomiting, diarrhea, abdominal pain/dyspepsia, headache, dizziness, rash/pruritus; clinically important: elevated liver enzymes/hepatotoxicity, edema (and potential worsening heart failure), and hypokalemia.

Side Effect Frequency

Common (≥1% to <10%): nausea, abdominal pain/dyspepsia, diarrhea, vomiting, headache; Common/Uncommon: elevated liver enzymes, rash/pruritus, dizziness, edema/hypokalemia (frequency varies by source); Rare but serious: hepatotoxicity, congestive heart failure (negative inotrope/boxed warning in some labels), severe cutaneous reactions (e.g., SJS/TEN), peripheral neuropathy.

Safety & Warnings

Contraindications

Contraindicated: hypersensitivity to itraconazole/azole antifungals; coadministration with contraindicated CYP3A substrates (e.g., cisapride, pimozide, quinidine, dofetilide, certain ergot alkaloids, oral midazolam/triazolam, simvastatin/lovastatin and other listed agents per label); and use for onychomycosis in patients with ventricular dysfunction/CHF; pregnancy is contraindicated for onychomycosis (and generally avoid unless benefit outweighs risk for serious systemic infection).

Warnings & Precautions

Key warnings/precautions: CHF/negative inotropy-avoid in ventricular dysfunction and monitor for edema/dyspnea; hepatotoxicity-baseline and periodic LFTs and stop if hepatitis symptoms; major CYP3A4 interaction screening before prescribing; reduced capsule absorption with acid suppression (separate/avoid as appropriate); pregnancy avoidance for non-life-threatening indications and effective contraception during and after therapy per label; discontinue if neuropathy or severe rash occurs; capsule and oral solution are not interchangeable due to different bioavailability.

Age Restriction

Not routinely approved/recommended for children; may be used in pediatrics only when benefits outweigh risks under specialist supervision (off‑label in many settings).

Driving Warning

Caution - May cause CNS depression, which may impair mental alertness and subsequently impair ability to operate heavy machinery or performing hazardous tasks

Drug Interactions

Drug Interactions

Major interactions: strong CYP3A inducers (rifampin/rifabutin, phenytoin, carbamazepine, phenobarbital, St John’s wort) markedly reduce itraconazole exposure; itraconazole (strong CYP3A4/P-gp inhibitor) increases levels/toxicity of many drugs-contraindicated examples include cisapride/pimozide/quinidine/dofetilide (arrhythmias), ergot alkaloids (ergotism), simvastatin/lovastatin (rhabdomyolysis), oral midazolam/triazolam (profound sedation). Other clinically important interactions: warfarin (↑INR), digoxin (↑levels), cyclosporine/tacrolimus/sirolimus (↑levels), some calcium-channel blockers (↑edema/CHF risk), and acid-suppressants/antacids reduce capsule absorption.

Interaction Severity

MAJOR/contraindicated: strong CYP3A4-substrate drugs with serious toxicity risk (e.g., cisapride, pimozide, quinidine/dofetilide and other QT-prolonging antiarrhythmics, ergot alkaloids, oral midazolam/triazolam, simvastatin/lovastatin). MODERATE/clinically significant: warfarin, digoxin, cyclosporine/tacrolimus/sirolimus, calcium channel blockers (edema/CHF risk), and strong enzyme inducers (rifampin, carbamazepine, phenytoin) which can markedly reduce itraconazole levels; acid suppressants reduce capsule absorption.

Food Interaction

Capsules: take immediately after a full meal to increase absorption; reduced gastric acidity decreases absorption-an acidic beverage (e.g., non-diet cola) can help if acid suppression cannot be avoided.

Special Populations

Pregnancy

Contraindicated

Children

Not routinely approved for children; limited data available. When used in life-threatening situations: 5 mg/kg/day has been used under specialist supervision

Elderly

Start at lower dose, titrate slowly, monitor renal function. Use only if the potential benefit outweighs the potential risks, considering the higher frequency of decreased hepatic, renal, or cardiac function.

Kidney Impairment

No routine dose adjustment for mild-moderate renal impairment; use caution in severe renal impairment (variable exposure and formulation-related issues) and consider therapeutic drug monitoring for prolonged therapy.

Liver Impairment

No standardized dose adjustment; use with caution in hepatic impairment, consider dose reduction/therapeutic drug monitoring when prolonged therapy is needed, and monitor LFTs closely-avoid or use only if essential in severe hepatic disease.

Storage & Patient Advice

Missed Dose

Take the missed dose as soon as remembered (with a full meal for capsules); if it is close to the next dose, skip the missed dose and resume the regular schedule-do not double.

Stopping the Medicine

Do not stop early without prescriber advice; complete the prescribed course unless significant adverse effects occur (then stop and seek medical care).

Patient Counseling

Take capsules immediately after a full meal and swallow whole; avoid/space antacids and be aware PPIs/H2 blockers can reduce absorption (acidic beverage may help). Report liver injury symptoms (jaundice, dark urine, severe fatigue) and heart failure symptoms (shortness of breath, swelling, rapid weight gain). Check for drug interactions before starting any new medicine. Complete the prescribed course; nail infections may take months to look better.

Monitoring Requirements

Baseline and periodic liver function tests (especially if therapy >1 month or in hepatic disease); monitor for signs/symptoms of heart failure/edema; consider potassium monitoring if clinically indicated; therapeutic drug monitoring (itraconazole trough levels) may be used for severe infections, prolonged therapy, suspected malabsorption, or drug interactions.

Pharmacology

Mechanism of Action

Inhibits fungal lanosterol 14α-demethylase (CYP51), decreasing ergosterol synthesis and disrupting fungal cell membrane structure and function.

Onset of Action

Peak plasma concentrations typically occur about 2-5 hours after a capsule dose; clinical response varies by infection and may take days to weeks (and months for nail disease).

Duration of Effect

For onychomycosis, itraconazole persists in nail keratin and antifungal activity can continue for months after stopping (commonly ~6-9 months in toenails).

Half-Life

Terminal half-life: ~16-28 hours after a single dose; increases to ~34-42 hours after repeated dosing (steady state).

Metabolism

Extensive hepatic metabolism primarily via CYP3A4; major active metabolite is hydroxy-itraconazole (antifungal activity comparable to parent).

Product Information

Available Dosage Forms

Capsule, Oral solution, Tablet.

Composition per Dose

Each capsule: 100 mg itraconazole (as coated pellets)

Generic Availability

Yes

OTC Alternatives

No OTC alternative for systemic fungal infections; topical OTC antifungals (clotrimazole, miconazole) available for superficial skin infections only

Application

Oral

Reviewed by Al Mujtama Pharmacy Medical Review Team. Last reviewed 27-07-2026