NYSTATIN
Clinical safety rating: safe
Animal studies have demonstrated safety
Nystatin binds to sterols in the fungal cell membrane, primarily ergosterol, altering membrane permeability and causing leakage of intracellular components, leading to fungal cell death.
| Metabolism | Nystatin is not absorbed from the gastrointestinal tract, skin, or mucous membranes after topical or oral administration; systemic metabolism is minimal. |
| Excretion | Nystatin is not absorbed from the gastrointestinal tract after oral administration; virtually 100% of the ingested dose is excreted unchanged in the feces. After topical application, systemic absorption is negligible; any absorbed drug is excreted via bile and feces (<1% renal). |
| Half-life | Due to minimal systemic absorption, a terminal elimination half-life is not clinically relevant. In vitro plasma degradation half-life is approximately 1.5 hours, but this is not applicable in vivo. |
| Protein binding | Not clinically relevant due to negligible systemic absorption. In vitro binding to plasma proteins is not typically reported. |
| Volume of Distribution | Not applicable due to lack of systemic absorption. After oral administration, drug remains in GI tract; Vd cannot be determined. |
| Bioavailability | Oral: <1% systemic bioavailability due to poor absorption from GI tract. Topical: Negligible absorption through intact skin or mucous membranes. Vaginal: Minimal systemic absorption. |
| Onset of Action | Oral: Clinical response usually seen within 24 hours. Topical: Relief of symptoms may occur within 24–72 hours. Vaginal tablets: Improvement noted within 48–72 hours. |
| Duration of Action | Oral suspension: Effect persists as long as contact with mucosa; treatment typically continued for 48 hours after resolution of symptoms. Topical creams: Duration depends on continued application; prolonged use (at least 2 weeks) often needed for vaginal candidiasis to prevent relapse. |
| Molecular Weight | 926.11 |
Oral: 500,000 to 1,000,000 units (5-10 mL suspension) swish and swallow 3-4 times daily; Vaginal: 1 vaginal tablet (100,000 units) once or twice daily; Topical: Apply cream/ointment 2-3 times daily; duration depends on indication.
| Dosage form | CREAM |
| Renal impairment | No dosage adjustment required for renal impairment. Nystatin is not systemically absorbed. |
| Liver impairment | No dosage adjustment required for hepatic impairment. Nystatin is not systemically absorbed. |
| Pediatric use | Oral suspension: Neonates and infants: 200,000 units (2 mL) four times daily; Children: 500,000 to 1,000,000 units (5-10 mL) four times daily. Topical and vaginal: Use same as adult. |
| Geriatric use | No specific dose adjustment; use caution with oral suspension due to aspiration risk in elderly with dysphagia. Use topical formulations as tolerated. |
| 1st trimester | No evidence of fetal harm in animal studies; limited human data suggests safety. |
| 2nd trimester | Generally considered safe; minimal systemic absorption. |
| 3rd trimester | Safe; used for maternal infections near term. |
Clinical note
No significant drug interactions For topical or oral use only not for systemic use.
| Placental transfer | Minimal to none due to poor oral absorption and high molecular weight; not expected to cross significantly. |
| Breastfeeding | Not absorbed systemically via oral/vaginal use; considered compatible with breastfeeding. Avoid topical application to breast if infant may ingest. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Common Effects | cutaneous) |
| Serious Effects |
Hypersensitivity to nystatin or any component of the formulation
| Precautions | Hypersensitivity reactions including angioedema and rash, Irritation of skin or mucous membranes with prolonged use, Discontinue if irritation or sensitization occurs |
| Food/Dietary | No known food interactions. However, avoid eating or drinking for 30 minutes after using oral suspension to maximize mucosal contact time. |
Loading safety data…
| L1 (Safest) |
| Teratogenic Risk | Nystatin is poorly absorbed from the gastrointestinal tract and is not expected to reach significant systemic concentrations. No teratogenic effects have been reported in animal studies. In humans, there is no evidence of fetal harm; it is considered safe for use during all trimesters when administered topically or orally for local antifungal treatment. |
| Fetal Monitoring | No specific maternal or fetal monitoring is required for nystatin use during pregnancy. Standard prenatal care should be continued. |
| Fertility Effects | Systemic exposure is negligible, and no adverse effects on fertility have been reported. Nystatin is not expected to impact reproductive function. |
| Clinical Pearls | Nystatin is a polyene antifungal that binds to ergosterol in fungal cell membranes, causing leakage and cell death. It is not absorbed systemically when given orally or applied topically. For oral thrush, use the suspension as a 'swish and swallow' (hold in mouth for several minutes before swallowing). For cutaneous candidiasis, apply thin layer to affected area twice daily. Consider using nystatin powder for moist intertriginous areas to reduce maceration. Vaginal tablets can be used during pregnancy (category A). Nystatin is ineffective against dermatophytes. |
| Patient Advice | For oral suspension: swish the medication around in your mouth for as long as possible (at least 2 minutes) before swallowing. Do not eat or drink for 30 minutes afterward. · Complete the full course of treatment even if symptoms improve, to prevent recurrence. · Apply topical creams thinly to affected areas; avoid occlusion. · For vaginal tablets: insert one tablet high into the vagina nightly for 14 days. Continue during menstrual period. · Store at room temperature, away from moisture and heat. · Contact your healthcare provider if symptoms worsen or do not improve within a few days. |