What are troches (lozenges)?

What Are Troches (Lozenges)?

Troches are large, slowly dissolving tablets (lozenges) designed to be held in the mouth until completely dissolved, delivering medication directly to the oral mucosa. 1

Pharmaceutical Composition

• Clotrimazole troches contain 10 mg of the active antifungal agent clotrimazole dispersed in dextrose, microcrystalline cellulose, povidone, and magnesium stearate. 1
• The troche formulation is specifically engineered as a large tablet that dissolves slowly over time, allowing prolonged contact with oral tissues. 1

Mechanism of Action and Administration

• Troches must be slowly dissolved in the mouth—they should never be chewed or swallowed whole. 1
• The patient retains the troche in the mouth until it completely dissolves, typically taking 15-30 minutes per dose. 2
• This delivery method provides topical antifungal activity directly at the site of infection with minimal systemic absorption. 3, 4

Clinical Indications

Treatment of Oropharyngeal Candidiasis

• For mild oropharyngeal candidiasis, clotrimazole troches (10 mg five times daily for 7-14 days) are recommended as first-line topical therapy. 3, 1
• The Infectious Diseases Society of America guidelines support troches as an effective option for mild disease, though oral fluconazole is superior for moderate to severe cases. 3

Prophylaxis in Immunocompromised Patients

• Troches are indicated prophylactically (10 mg three times daily) to reduce the incidence of oropharyngeal candidiasis in patients immunocompromised by chemotherapy, radiotherapy, or steroid therapy. 1
• Studies demonstrate that clotrimazole troches prevent oral candidiasis in 87% of patients receiving prophylaxis compared to 43% with placebo. 5

Important Clinical Considerations

Advantages of Troches

• Troches work locally without systemic absorption, avoiding drug-drug interactions and systemic side effects. 3, 4
• The topical mechanism makes troches particularly useful when systemic antifungal therapy poses interaction risks or is contraindicated. 4

Critical Pitfall: Drug Interactions Despite "Topical" Route

• Despite minimal systemic absorption, clotrimazole troches can significantly affect tacrolimus levels through intestinal CYP450 enzyme inhibition. 6
• In heart transplant recipients, discontinuing clotrimazole troches required a median tacrolimus dose increase of 66.7%, with trough levels dropping by 42.5%. 6
• Close monitoring of immunosuppressant levels is mandatory when starting or stopping clotrimazole troches, even though they are considered "topical." 6

Resistance Development

• Prolonged or repeated use of clotrimazole troches can lead to azole resistance, particularly in HIV-infected patients. 7
• When clotrimazole MIC ≥0.5 μg/mL, there is significant cross-resistance to other azoles (fluconazole, itraconazole) and a 7.2-fold increased risk of requiring amphotericin B for refractory disease. 7
• Therapy should be limited to short-term use when possible to minimize resistance development. 1

Efficacy Compared to Systemic Therapy

• While troches are effective for mild disease, oral fluconazole (100-200 mg daily) is superior and more convenient for moderate to severe oropharyngeal candidiasis. 3
• The CDC notes that fluconazole achieves faster symptom resolution and higher cure rates than topical agents including troches. 3, 8

Dosing Regimens

Treatment Dosing

• Standard treatment: One 10-mg troche five times daily for 14 consecutive days. 1

Prophylaxis Dosing

• Prophylactic regimen: One 10-mg troche three times daily for the duration of immunosuppressive therapy. 1