Sporanox

Sporanox (spôr-nks)

A trademark for the drug itraconazole.

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itraconazole

Sporanox

Pharmacologic class: Synthetic triazole

Therapeutic class: Antifungal

Pregnancy risk category C

FDA Boxed Warning

• Don't administer capsules to treat onychomycosis in patients with evidence of ventricular dysfunction, such as current or previous heart failure. If heart failure signs or symptoms occur during therapy, discontinue drug.
• Concurrent use of cisapride, dofetilide, levacetylmethadol (levomethadyl), pimozide, or quinidine with itraconazole capsules or oral solution is contraindicated. Itraconazole is a potent CYP3A4 inhibitor and may raise blood levels of drugs metabolized by this pathway. Serious cardiovascular events (including QT prolongation, torsades de pointes, ventricular tachycardia, cardiac arrest, and sudden death) have occurred in patients taking these drugs concurrently with itraconazole.

Action

Prevents ergosterol synthesis in fungal cell membranes, altering membrane permeability

Availability

Capsules: 100 mg

Oral solution: 10 mg/ml

⊘Indications and dosages

➣ Aspergillosis; blastomycosis; histoplasmosis

Adults: 200 to 400 mg P.O. daily for at least 3 months until patient is cured. In life-threatening infections, loading dose of 200 mg P.O. t.i.d. for 3 days, then 200 to 400 mg P.O. daily until cured.

➣ Esophageal candidiasis

Adults: 100 to 200 mg of oral solution daily, swished in mouth for several seconds and swallowed, for at least 3 weeks; continue for 2 weeks after symptoms resolve.

➣ Oropharyngeal candidiasis

Adults: 200 mg of oral solution daily, swished in mouth for several seconds and swallowed, for 1 to 2 weeks

➣ Onychomycosis; tinea unguium

Adults: For toenails, 200 mg P.O. daily for 12 weeks. For fingernails, 200 mg b.i.d. for 1 week; wait 3 weeks, then repeat dosage for 1 week.

Contraindications

• Hypersensitivity to drug or its components
• Fungal meningitis
• Ventricular dysfunction, heart failure (in onychomycosis use)
• Concomitant use of astemizole, cisapride, dofetilide, lovastatin, midazolam, pimozide, quinidine, simvastatin, or triazolam
• Pregnancy or anticipated pregnancy (in onychomycosis use)

Precautions

Use cautiously in:
• hypersensitivity to other azole derivatives
• renal impairment (with I.V. use), hepatic disorders, achlorhydria, hypochlorhydria
• breastfeeding patients
• children (safety and efficacy not established).

Administration

• Obtain specimens for fungal cultures, as needed, before starting therapy.
• Administer capsule with a full meal.
• Give oral solution without food when possible.
• Be aware that liquid and tablets aren't interchangeable.

Route	Onset	Peak	Duration
P.O.	Slow	4-6 hr	4-6 days

Adverse reactions

CNS: dizziness, headache, fatigue, malaise

CV: peripheral edema, tachycardia, heart failure

EENT: rhinitis

GI: nausea, vomiting, constipation, abdominal pain, flatulence, anorexia, dyspepsia

GU: albuminuria, erectile dysfunction

Hepatic: jaundice, hepatotoxicity (including hepatic failure and death )

Metabolic: hypokalemia

Musculoskeletal: myalgia, bursitis, rhabdomyolysis

Respiratory: pulmonary edema

Skin: flushing, rash, pruritus, urticaria, increased sweating, herpes zoster infection

Other: fever, pain

Interactions

Drug-drug. Alfentanil, antihistamines (minimally sedating agents, such as fexofenadine, loratadine), antineoplastics (busulfan, docetaxel, vinca alkaloids), anxiolytics, benzodiazepines, cyclosporine, delavirdine, digoxin, immunosuppressants, methylprednisolone, protease inhibitors, tacrolimus, tolterodine, tretinoin: increased blood levels of these drugs

Amiodarone, anabolic steroids, androgens, antithyroid drugs, carmustine, chloroquine, dantrolene, daunorubicin, disulfiram, estrogens, gold salts, hormonal contraceptives, hydroxychloroquine, mercaptopurine, methotrexate, methyldopa, naltrexone (with long-term use), valproic acid: increased risk of hepatic damage

Amphotericin B: reduced or inhibited amphotericin B effects

Antacids, anticonvulsants, antimycobacterials, cyclobenzaprine, histamine₂-receptor blockers, isoniazid, proton pump inhibitors (such as lansoprazole, omeprazole), reverse transcriptase inhibitors, sucralfate: reduced itraconazole blood level

Antipsychotics, antiarrhythmics (such as quinidine, dofetilide), anxiolytics, astemizole, cisapride: increased risk of serious cardiovascular effects

Calcium channel blockers: increased risk of edema, possible increase in itraconazole's effect

Carbamazepine, carbidopa, levodopa: altered blood levels of these drugs

Didanosine, vinblastine, vincristine, xanthine bronchodilators: decreased efficacy of these drugs

Digoxin: increased digoxin blood level, possible digoxin toxicity

HMG-CoA reductase inhibitors, miconazole: inhibited metabolism of these drugs, increased risk of skeletal muscle toxicity (including rhabdomyolysis)

Macrolide antibiotics: increased itraconazole blood level

Oral hypoglycemics: severe blood glucose decrease

Quetiapine, sildenafil: increased efficacy of these drugs

Warfarin: enhanced anticoagulant effect

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, blood urea nitrogen, gamma-glutamyltransferase, serum creatinine: increased levels

Potassium, magnesium: decreased levels

Drug-food. Any food, cola: increased itraconazole blood level

Grapefruit juice: decreased blood level and reduced therapeutic effects of itraconazole

Drug-herbs. Chaparral, comfrey, germander, jin bu huan, kava: increased risk of hepatic damage

Drug-behaviors. Alcohol consumption: toxic reaction, hepatic damage

Patient monitoring

• In patient with hepatic dysfunction, monitor hepatic enzyme levels.
☞ Monitor for signs and symptoms of hepatic dysfunction (jaundice, fatigue, nausea, vomiting, dark urine, pale stools), heart failure, muscle disorder, and pulmonary or peripheral edema.
• Monitor potassium level. Stay alert for hypokalemia.

Patient teaching

• Tell patient he may take capsule with a full meal. If he's using oral solution, advise him to take it without food.
• Inform patient that drug interacts with many other drugs. Advise him to tell all prescribers he's taking it.
☞ Teach patient to recognize and immediately report signs and symptoms of hepatic dysfunction, persistent muscle pain, and heart failure.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• Advise female patient of childbearing potential to use effective contraception during and for 1 month after therapy. Caution her not to breastfeed.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.