Itraconazole
Brand names: Sporanox, Itrimul
Itraconazole is a triazole antifungal used for dermatophyte (e.g. nail), candidal and some systemic fungal infections.
Adult dose
Dose adjustments
Limited data are available on the use of oral itraconazole in patients with renal impairment. Exposure may be lower in some patients with renal insufficiency, with wide inter-subject variation. Exercise caution; adjusting the dose or switching to an alternative antifungal may be considered based on an evaluation of clinical effectiveness (eMC §4.2).
Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.
US labelling (FDA)
Reference — US labelling, may differ from UKDOSAGE AND ADMINISTRATION Itraconazole capsules should be taken with a full meal to ensure maximal absorption. Itraconazole capsules must be swallowed whole. Itraconazole capsule is a different preparation than itraconazole Oral Solution and should not be used interchangeably. Treatment of Blastomycosis and Histoplasmosis: The recommended dose is 200 mg once daily (2 capsules). If there is no obvious improvement, or there is evidence of progressive fungal disease, the dose should be increased in 100-mg increments to a maximum of 400 mg daily. Doses above 200 mg/day should be given in two divided doses. Treatment of Aspergillosis: A daily dose of 200 to 400 mg is recommended. Treatment in …
Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-03-10. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.
Contraindications
- Known hypersensitivity to itraconazole or to any of the excipients
- Evidence of ventricular dysfunction such as congestive heart failure (CHF) or a history of CHF — except for the treatment of life-threatening or other serious infections; capsules must NOT be given for onychomycosis in these patients (US label, BOXED WARNING territory)
- Must not be used during pregnancy for non-life-threatening indications
- Co-administration of a number of CYP3A4 substrates, including ergot alkaloids (dihydroergotamine, ergometrine, ergotamine, methylergometrine), isavuconazole, halofantrine, astemizole, mizolastine, terfenadine, irinotecan, venetoclax (during initiation/titration in CLL), dabigatran, ticagrelor, ombitasvir/paritaprevir/ritonavir, aliskiren, eplerenone, quinidine, bepridil, finerenone, ranolazine, disopyramide, ivabradine, sildenafil (pulmonary hypertension), dofetilide, lercanidipine, dronedarone, nisoldipine, cisapride, domperidone, naloxegol, voclosporin, lovastatin, lomitapide, simvastatin, lurasidone, pimozide, sertindole, oral midazolam, quetiapine, triazolam, avanafil, darifenacin, dapoxetine
- Conditional contraindications: solifenacin (severe renal or moderate-to-severe hepatic impairment), fesoterodine (moderate or severe renal or hepatic impairment), vardenafil (age over 75 years), colchicine (renal or hepatic impairment), eliglustat (CYP2D6 poor or intermediate metabolisers, or extensive metabolisers taking a strong or moderate CYP2D6 inhibitor)
Side effects
- Dizziness, headache and dysgeusia (common)
- Abdominal pain, diarrhoea, vomiting, nausea and dyspepsia (common); constipation (uncommon); pancreatitis (not known)
- Rash (common); urticaria and pruritus (uncommon); serious skin reactions including toxic epidermal necrolysis, Stevens-Johnson syndrome, acute generalised exanthematous pustulosis, erythema multiforme, exfoliative dermatitis, leukocytoclastic vasculitis, alopecia and photosensitivity (not known)
- Cardiac failure (uncommon); congestive heart failure and bradycardia (not known); dyspnoea and cough (common)
- Hepatic failure and hyperbilirubinaemia (uncommon); serious hepatotoxicity including some cases of fatal acute liver failure (not known)
- Hypersensitivity (uncommon); serum sickness, angioneurotic oedema and anaphylactic reaction (not known); hypokalaemia, leukopenia and thrombocytopenia (uncommon)
Interactions
- Itraconazole and its major metabolite hydroxy-itraconazole are potent CYP3A4 inhibitors and inhibitors of the drug transporters P-glycoprotein and BCRP, so itraconazole can markedly increase (or sometimes decrease) concentrations of many concomitant drugs
- Increased concentrations of co-administered drugs may cause severe or life-threatening reactions — e.g. QT prolongation, torsade de pointes, respiratory depression, hepatic reactions, hypersensitivity, myelosuppression, hypotension, seizures, angioedema, atrial fibrillation, bradycardia, priapism
- Co-administration of a number of CYP3A4 substrates is contraindicated outright (see contraindications list)
- Reduced concentrations of concomitant drugs may reduce their efficacy — check the approved product labelling of each co-prescribed drug before starting itraconazole
- Absorption is formulation-dependent: capsules require a full meal, the oral solution requires an empty stomach — do not interchange the two preparations
Clinical monograph
How it works
It inhibits fungal ergosterol synthesis, impairing the fungal cell membrane.
Prescribing in practice
- It is a strong CYP3A4 inhibitor with many serious interactions (e.g. with some statins, certain other drugs) — review co-medication.
- It has a negative inotropic effect — avoid in heart failure or a history of it.
- Hepatotoxicity can occur; capsule absorption needs stomach acid and food (the oral solution differs).
Monitoring
Consider liver function with longer courses; review interactions and cardiac status.
Counselling the patient
- Take capsules with food.
- Tell your clinician about all other medicines, as itraconazole interacts with many.
- Report breathlessness or ankle swelling, or yellowing of the skin/eyes.
Evidence & guidelines
Used for dermatophyte, candidal and some systemic fungal infections, with attention to interactions and cardiac effects.
Reference: MHRA Drug Safety Update (Heart failure); BAD Onychomycosis Guidelines 2014; NICE CKS Fungal Nail Infection; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.
- Suspicious Pigmented Lesion — Melanoma Pathway · NICE NG14 2015 / BAD
- Cellulitis and Erysipelas · NICE NG141 2019 / CREST
- Psoriasis — Severity Assessment and Step-Up Therapy · NICE NG153 2019 / BAD
- Atopic Eczema — Assessment and Step-Up Therapy · NICE NG95 2023
- Urticaria and Angioedema · BSACI / EAACI Guidelines 2022
- Acne Vulgaris — Grading and Treatment · NICE NG198 2021 / BAD