PREDSULFAIR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PREDSULFAIR (PREDSULFAIR).
PREDSULFAIR is a combination of prednisolone (corticosteroid) and sulfacetamide (sulfonamide antibiotic). Prednisolone suppresses inflammation by inhibiting phospholipase A2, reducing prostaglandin and leukotriene synthesis. Sulfacetamide inhibits bacterial dihydropteroate synthase, blocking folate synthesis.
| Metabolism | Prednisolone is primarily metabolized in the liver via CYP3A4. Sulfacetamide is metabolized via acetylation and glucuronidation. |
| Excretion | PREDSULFAIR is a fixed-dose combination of prednisolone and sulfafurazole. Prednisolone is primarily metabolized hepatically; inactive metabolites are excreted renally (<30% unchanged). Sulfafurazole is acetylated and glucuronidated; parent drug and metabolites are excreted renally (≥90%, with 15-30% unchanged). Biliary/fecal elimination is minimal for both components (<5%). |
| Half-life | Prednisolone: 2.1–3.5 hours (plasma); biological half-life 12–36 hours (duration of HPA axis suppression). Sulfafurazole: 3–6 hours (normal renal function), prolonged to 12–24 hours in renal impairment. |
| Protein binding | Prednisolone: 70–90% bound to corticosteroid-binding globulin (CBG) and albumin; binding decreases at higher doses. Sulfafurazole: 40–60% bound to albumin; binding decreases in uremia. |
| Volume of Distribution | Prednisolone: Vd 0.5–1.0 L/kg, indicating extensive distribution into tissues. Sulfafurazole: Vd 0.2–0.4 L/kg, primarily confined to extracellular fluid. |
| Bioavailability | Oral: Prednisolone ~80–100% (immediate-release); sulfafurazole ~90–100%. Ophthalmic: corneal penetration ~2–10% for prednisolone; sulfafurazole limited to topical effect with minimal systemic absorption. |
| Onset of Action | Oral: Prednisolone anti-inflammatory effect within 2–4 hours; peak plasma levels at 1–2 hours. Ophthalmic: Onset within 30–60 minutes for ocular inflammation. Sulfafurazole bacteriostatic effect begins within 2–4 hours after oral administration. |
| Duration of Action | Prednisolone: Anti-inflammatory effect persists 12–36 hours after single oral dose; ophthalmic effect 4–6 hours. Sulfafurazole: Antimicrobial effect for 6–12 hours depending on dose and renal function. |
Prednisolone 0.5-1 mg/kg orally once daily, maximum 60 mg/day; Sulfasalazine 500 mg orally twice daily, increased by 500 mg weekly to maintenance 2-3 g/day in divided doses.
| Dosage form | OINTMENT |
| Renal impairment | eGFR >50 mL/min: no adjustment; eGFR 10-50 mL/min: reduce sulfasalazine dose by 50%; eGFR <10 mL/min: contraindicated (sulfasalazine). Prednisolone no adjustment. |
| Liver impairment | Child-Pugh A: caution with prednisolone; avoid sulfasalazine. Child-Pugh B: reduce prednisolone dose by 50%; avoid sulfasalazine. Child-Pugh C: contraindicated. |
| Pediatric use | Prednisolone: 1-2 mg/kg/day orally in divided doses, maximum 60 mg/day. Sulfasalazine: 30-50 mg/kg/day orally in 2-4 divided doses, maximum 2 g/day. |
| Geriatric use | Start at lowest effective dose; monitor for osteoporosis, hyperglycemia, and immunosuppression with prednisolone; sulfasalazine: increased risk of hematologic toxicity; monitor CBC and renal function regularly. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PREDSULFAIR (PREDSULFAIR).
| Breastfeeding | Prednisolone enters breast milk in low concentrations (~5-25% of maternal dose, M/P ratio ~0.3-0.5). Peak milk level 1-2 hours after dose. Delaying breast-feeding for 4 hours after dose reduces exposure. Likely safe at doses <20 mg/day; with higher doses, monitor infant for adrenal suppression. |
| Teratogenic Risk | Prednisolone crosses the placenta but is largely inactivated by placental 11β-HSD2. First trimester exposure (≤15 mg/day) is not associated with major malformations; risk of cleft palate increases with doses >15 mg/day (absolute risk ~1-2%). Second/third trimester: possible intrauterine growth restriction, preterm birth, adrenal suppression in neonate. High doses (>30 mg/day) increase risk of premature rupture of membranes. |
■ FDA Black Box Warning
Sulfonamides are associated with severe adverse reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias. Prolonged use of corticosteroids may result in elevated intraocular pressure, glaucoma, cataracts, and secondary ocular infections.
| Serious Effects |
Hypersensitivity to sulfonamides or corticosteroids. Epithelial herpes simplex keratitis (dendritic keratitis), vaccinia, varicella, mycobacterial ocular infections, fungal diseases of the eye, and untreated parasitic infections.
| Precautions | Prolonged use may lead to increased intraocular pressure, glaucoma, cataract formation, delayed wound healing, and secondary infections. Sulfonamide components may cause hypersensitivity reactions including Stevens-Johnson syndrome. Use with caution in patients with glaucoma, corneal thinning, or known sulfonamide allergy. Bacterial resistance may develop with prolonged use. |
Loading safety data…
| Fetal Monitoring | Monitor maternal blood pressure, blood glucose, weight gain, signs of infection. Fetal ultrasound for growth and amniotic fluid volume. Neonatal assessment for adrenal insufficiency (e.g., cortisol levels) if mother received >15 mg/day in late pregnancy. |
| Fertility Effects | No direct impairment of fertility. Chronic high doses may cause menstrual irregularities or suppress HPA axis, potentially affecting ovulation; reversible upon dose reduction. |