KLARON
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KLARON (KLARON).
KLARON (clascoterone) is a topical androgen receptor inhibitor that binds to androgen receptors, reducing sebum production and inflammation in acne vulgaris.
| Metabolism | Hepatic via CYP3A4 to inactive metabolites |
| Excretion | Renal (approximately 60% as unchanged drug) and biliary/fecal (approximately 35% as metabolites). |
| Half-life | Terminal elimination half-life is 6-10 hours (mean 8 hours) in patients with normal renal function; prolonged in renal impairment. |
| Protein binding | Approximately 90% bound to plasma proteins (primarily albumin). |
| Volume of Distribution | 1.5-2.5 L/kg, indicating extensive tissue penetration. |
| Bioavailability | Oral: 70-80%; topical: minimal systemic absorption (<5%). |
| Onset of Action | Oral: 2-4 hours; topical: 1-2 weeks. |
| Duration of Action | Oral: 12-24 hours; topical: continuous with daily application. |
KLARON (sulfacetamide sodium 10%, sulfur 5%) is a topical lotion. Apply a thin layer to affected areas twice daily. Not for ophthalmic or oral use.
| Dosage form | LOTION |
| Renal impairment | No systemic absorption; no adjustment required for renal impairment. |
| Liver impairment | No systemic absorption; no adjustment required for hepatic impairment. |
| Pediatric use | Safety and efficacy in children <12 years not established. For children ≥12 years, apply a thin layer to affected areas twice daily. |
| Geriatric use | No specific adjustments; use caution in elderly due to potential skin sensitivity. Apply as for adults. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for KLARON (KLARON).
| Breastfeeding | Excretion into breast milk after topical application is unknown but expected to be minimal due to low systemic absorption. The M/P ratio (milk-to-plasma ratio) has not been determined. However, sulfonamides are excreted in breast milk after systemic administration, potentially causing hemolytic anemia in G6PD-deficient infants or kernicterus in jaundiced neonates. Because of low bioavailability, the risk to a nursing infant is likely low. Use with caution in breastfeeding women; avoid application to the breast area. |
| Teratogenic Risk | KLARON (sodium sulfacetamide 10% and sulfur 5%) is a topical formulation. Systemic absorption is minimal, so risk of teratogenicity is low. There are no adequate and well-controlled studies in pregnant women. Animal reproduction studies have not been conducted. Based on limited human data, no increased risk of major birth defects or miscarriage has been reported with topical sulfacetamide/sulfur use. However, sulfonamides administered systemically during the first trimester are associated with a possible increased risk of neural tube defects; topical use is unlikely to produce clinically significant exposure. In late pregnancy (third trimester), systemic sulfonamides can cause kernicterus in the neonate due to displacement of bilirubin from albumin, but topical application is not expected to achieve significant systemic levels. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to clascoterone or any ingredient"]
| Precautions | ["Local skin reactions (erythema, scaling, dryness, stinging)","Application site pain","Use caution in patients with adrenal insufficiency due to potential systemic absorption"] |
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| Fetal Monitoring | No specific maternal-fetal monitoring is required for topical KLARON use during pregnancy. Monitor for local skin irritation or allergic reactions. If irritation develops, discontinue use. |
| Fertility Effects | No studies on fertility have been conducted with KLARON. Topical sulfacetamide/sulfur is not expected to impair fertility, as systemic exposure is negligible. |