Extina

Action

Alters fungal cell membranes, resulting in increased permeability, growth inhibition, and ultimately, cell death

Availability

Cream: 2%

Shampoo: 1%, 2%

Tablets: 200 mg

Indications and dosages

➣ Blastomycosis; chronic mucocutaneous candidiasis; oral thrush; candiduria; coccidioidomycosis; histoplasmosis; chromomycosis; paracoccidioidomycosis; mucocutaneous or vaginal candidiasis

Adults: 200 to 400 mg P.O. daily

Children ages 2 and older: 3.3 to 6.6 mg/kg P.O. as a single daily dose. Duration depends on infection: for candidiasis, 1 to 2 weeks; other systemic mycoses, 6 months; recalcitrant dermatophyte infections involving glabrous skin, 4 weeks. Chronic mucocutaneous candidiasis requires maintenance therapy.

➣ Scaling caused by dandruff or seborrheic dermatitis

Adults: 2% shampoo applied topically twice weekly for 4 weeks, then as needed to control symptoms, with at least 3 days between applications; or 1% shampoo applied topically q 3 to 4 days for up to 8 weeks, then as needed to control dandruff

➣ Tinea corporis; tinea cruris; tinea versicolor; tinea pedis, cutaneous candidiasis

Adults: 2% cream applied topically to affected areas daily for 2 weeks (except for tinea pedis, which may require 6 weeks of therapy)

Contraindications

• Hypersensitivity to drug or its components

• Concurrent oral astemizole, cisapride, triazolam, or terfenadine therapy

Precautions

Use cautiously in:

• renal or hepatic disease, achlorhydria

• pregnant or breastfeeding patients

• children younger than age 2.

Administration

• Apply cream to damp skin of affected area and wide surrounding area.

• To use shampoo, wet hair, then apply shampoo and massage into scalp for 1 minute. Leave on for 5 minutes before rinsing. Rinse and repeat, this time leaving shampoo on scalp for 3 minutes before rinsing.

• Don't apply shampoo to broken or inflamed skin.

• In achlorhydria, dissolve 200-mg tablet in 4 ml of 0.2N hydrochloric acid solution.

• Withhold antacids for at least 2 hours after giving oral ketoconazole.

☞ Don't give concurrently with cisapride, available in U.S. for compassionate use only. (Astemizole and terfenadine are not available in U.S.)

Adverse reactions

CNS: headache, nervousness, dizziness, drowsiness, severe depression, suicidal ideation

EENT: photophobia

GI: nausea, vomiting, diarrhea, abdominal pain, anorexia

GU: erectile dysfunction, gynecomastia

Hematologic: purpura, hemolytic anemia, thrombocytopenia, leukopenia

Hepatic: hepatotoxicity

Metabolic: hyperlipidemia

Skin: pruritus, rash, dermatitis, urticaria, severe irritation, stinging, alopecia, abnormal hair texture, scalp pustules, oily skin, dry hair and scalp

Other: fever, chills, allergic reaction

Interactions

Drug-drug. Antacids, anticholinergics, histamine₂-receptor antagonists: decreased ketoconazole absorption

Cyclosporine: increased cyclosporine blood level

Isoniazid, rifampin: increased ketoconazole metabolism

Theophylline: decreased theophylline blood level

Topical corticosteroids: increased corticosteroid absorption

Triazolam (oral): increased triazolam effects

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase: increased levels

Hemoglobin, platelets, white blood cells: decreased levels

Drug-herbs. Yew: inhibited ketoconazole metabolism

Patient monitoring

☞ Assess for suicidal ideation and signs and symptoms of depression.

☞ Monitor for evidence of hepatotoxicity, such as nausea, fatigue, jaundice, dark urine, and pale stools.

• With long-term therapy, stay alert for adrenal crisis.

Patient teaching

☞ Advise patient to watch for signs and symptoms of depression and to immediately report suicidal thoughts.

☞ Teach patient to recognize and immediately report signs and symptoms of hepatotoxicity, such as unusual tiredness or yellowing of skin or eyes.

• Advise patient not to take antacids for at least 2 hours after oral ketoconazole.

• Instruct patient to apply cream to damp skin of affected area and wide surrounding area.

• Tell patient to wet hair before applying shampoo and to massage into scalp for 1 minute; then leave on for 5 minutes before rinsing off. Tell him to shampoo again, leaving it on for 3 minutes this time before rinsing.

• Caution patient not to apply shampoo to broken or inflamed skin.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.