Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
ELIDEL vs PROTOPIC
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Inhibits T-cell activation by binding to macrophilin-12 (FKBP-12) and inhibiting calcineurin, thereby blocking cytokine transcription.
Tacrolimus, a calcineurin inhibitor, binds to FKBP-12 and inhibits calcineurin, thereby blocking dephosphorylation and nuclear translocation of NFAT, reducing transcription of pro-inflammatory cytokines (e.g., IL-2, IFN-γ) in T-cells.
Atopic dermatitis unresponsive to or intolerant of other topical treatments,Off-label: psoriasis, vitiligo, rosacea, contact dermatitis, lichen sclerosus, cutaneous lupus erythematosus
Moderate to severe atopic dermatitis in non-immunocompromised patients where conventional therapy is inadvisable or ineffective,Prophylaxis of organ rejection in kidney or liver transplantation (systemic use, not topical),Off-label: Treatment of vitiligo, psoriasis, eczema of the face and neck (short-term)
Apply a thin layer of 1% cream to affected areas twice daily.
Apply a thin layer of 0.03% or 0.1% ointment to affected areas twice daily. Discontinue when lesions resolve. For adults, use 0.03% or 0.1%; 0.1% is not indicated for children.
Terminal elimination half-life: 30–45 hours (mean 35 hours) following topical application; clinically, twice-daily dosing ensures therapeutic concentrations.
Terminal half-life ranges from 6–20 hours in pediatric atopic dermatitis patients; prolonged in hepatic impairment (mean 8–35 hours).
Metabolized primarily by CYP3A4; major metabolite O-demethylated pimecrolimus.
Primarily hepatic via CYP3A4; also metabolized by CYP3A5. Topical absorption results in minimal systemic exposure, but systemic metabolism follows oral route.
Renal (negligible, <1% unchanged) and biliary/fecal (approximately 97% as metabolites); less than 1% of the dose is excreted renally as unchanged drug.
Primarily fecal (biliary) elimination of metabolites; <1% of parent drug excreted unchanged in urine.
99% bound to plasma proteins (primarily albumin and alpha-1-acid glycoprotein).
99% bound primarily to albumin and alpha-1-acid glycoprotein.
Vd ~ 10 L/kg (extensive tissue distribution); suggests significant extravascular binding and penetration into tissues.
Vd/F ~ 30–50 L/kg after oral administration, indicating extensive tissue distribution; topical absorption negligible.
Topical: Systemic bioavailability is approximately 4% (range 1–7%) of applied dose; absorption increases with extent of skin lesion and thickness of application.
Systemic bioavailability after topical application is <0.5% in adults with intact skin; increases in compromised skin barrier.
No dose adjustment required for any degree of renal impairment.
No dose adjustment required. Tacrolimus is not significantly renally excreted and systemic absorption is minimal.
No formal studies in hepatic impairment; use caution in severe impairment.
No specific dose adjustment for Child-Pugh class A or B. For severe hepatic impairment (Child-Pugh C), use with caution; consider starting at lower concentration (0.03%) due to potential increased systemic exposure.
Apply a thin layer of 1% cream twice daily for children aged 2 years and older; not indicated for children under 2 years.
Children (2-15 years): Apply 0.03% ointment twice daily. Do not use 0.1% in this age group. For children 2 years and older.
No specific dose adjustment recommended; apply a thin layer of 1% cream twice daily as for adults.
No specific dose adjustment required. Use minimum effective amount; monitor for cutaneous infections.
Long-term safety of topical calcineurin inhibitors has not been established; rare cases of malignancy (e.g., lymphoma, skin cancer) have been reported; use should be limited to short-term and intermittent treatment.
Long-term safety of topical calcineurin inhibitors has not been established. Although a causal relationship has not been established, rare cases of malignancy (e.g., lymphoma, skin cancer) have been reported in patients treated with topical calcineurin inhibitors. Therefore, continuous long-term use should be avoided, and application should be limited to areas of involvement.
Increased risk of infections (e.g., eczema herpeticum, varicella zoster); avoid use on malignant or premalignant skin conditions; lymphadenopathy; photosensitivity; not recommended in patients with Netherton syndrome; potential for systemic immunosuppression; monitor for local irritation.
Increased risk of infections (including herpes simplex, eczema herpeticum); avoid use on malignant or premalignant skin conditions; use with caution in patients with netherton syndrome; may cause photosensitivity; avoid concurrent UV exposure; monitor for lymphadenopathy; not for use in children <2 years (safety not established).
Hypersensitivity to pimecrolimus or any component of the formulation; history of malignancy; application to areas of active infection; Netherton syndrome; immunocompromised patients.
Hypersensitivity to tacrolimus or any component of the formulation; use in patients with known or suspected malignancy at the application site; use in immunocompromised patients (relative).
No known food interactions. Avoid grapefruit juice as it may increase drug levels (CYP3A4 inhibition).
No known food interactions with topical PROTOPIC. However, if absorbed systemically (rare), grapefruit juice may increase tacrolimus levels; avoid excessive consumption of grapefruit juice while using PROTOPIC.
FDA Pregnancy Category C. Systemic exposure is minimal after topical application, but animal studies have shown developmental toxicity. No adequate human studies; risk cannot be excluded. Avoid in pregnancy unless clearly needed.
Pregnancy Category C. Animal studies have shown embryotoxicity and teratogenicity at systemic exposures below human therapeutic levels. No adequate human studies in pregnant women. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus. First trimester: avoid if possible. Second and third trimesters: limited data; systemic absorption minimal with topical use, but theoretical risk remains.
Not recommended. Pimecrolimus is excreted in milk in animal studies; unknown in humans. M/P ratio not available. Potential for serious adverse reactions in nursing infants.
Not known if tacrolimus is excreted in human milk after topical administration. Systemic absorption is minimal (<0.5%), but caution is advised due to potential for infant immunosuppression. M/P ratio: not available. Consider benefit of breast-feeding vs risk of infant exposure.
No dose adjustment necessary; use minimal amount to control symptoms. Systemic absorption is negligible, so pharmacokinetic changes in pregnancy do not alter dosing.
No specific dose adjustments recommended for topical use due to minimal systemic absorption. However, limit application to smallest area and shortest duration needed. Avoid use on large areas, broken skin, or under occlusion to reduce systemic exposure.
Topical calcineurin inhibitor for atopic dermatitis, reserved as second-line therapy for mild-to-moderate eczema due to boxed warning for rare malignancy risk. Apply thin layer only; avoid occlusive dressings. Do not use in immunocompromised patients. Intermittent use is recommended; continuous long-term use safety not established.
PROTOPIC (tacrolimus) is a topical calcineurin inhibitor used for atopic dermatitis. It is steroid-sparing, thus avoiding skin atrophy and tachyphylaxis. Apply as a thin layer to affected areas. Avoid occlusive dressings. Can be used on face, neck, and intertriginous areas where topical steroids are riskier. Monitor for burning/stinging upon application, which often improves with continued use. Warn patients about rare risk of lymphoma and skin malignancy; use only as second-line therapy for short-term and intermittent treatment. Do not use in immunocompromised patients or those with active skin infections.
Apply only to affected skin areas; avoid eyes, mouth, and open wounds.,Use for short durations; do not use continuously for extended periods.,Avoid sun exposure and tanning beds; use sunscreen on treated areas.,Do not cover treated skin with bandages or wraps unless instructed.,Report any signs of infection, skin burning, or new skin growths to your doctor.,This drug is for external use only; wash hands after application unless treating hands.,Do not use if you have a weakened immune system or active skin infection.
Apply PROTOPIC exactly as prescribed; do not use more than directed.,Wash hands after application unless treating hands.,Do not cover treated area with bandages or dressings unless instructed.,Expect mild burning or stinging especially in the first few days; this usually resolves with continued use.,Avoid sun exposure and use sunscreen; protect treated areas from natural and artificial sunlight.,Do not use on infected skin; tell your doctor if you have an infection.,PROTOPIC is for external use only; do not get in eyes, mouth, or nose.,Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding.,Store at room temperature away from moisture and heat.,Report any signs of skin infection, rash, or swollen lymph nodes to your doctor immediately.
No interactions on record
No interactions on record
Common clinical questions about ELIDEL vs PROTOPIC, answered by our medical review team.
ELIDEL is a Topical Calcineurin Inhibitor that works by Inhibits T-cell activation by binding to macrophilin-12 (FKBP-12) and inhibiting calcineurin, thereby blocking cytokine transcription.. PROTOPIC is a Topical Calcineurin Inhibitor that works by Tacrolimus, a calcineurin inhibitor, binds to FKBP-12 and inhibits calcineurin, thereby blocking dephosphorylation and nuclear translocation of NFAT, reducing transcription of pro-inflammatory cytokines (e.g., IL-2, IFN-γ) in T-cells.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between ELIDEL and PROTOPIC depend on the specific clinical indication. These are both Topical Calcineurin Inhibitor agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of ELIDEL is: Apply a thin layer of 1% cream to affected areas twice daily.. The standard adult dose of PROTOPIC is: Apply a thin layer of 0.03% or 0.1% ointment to affected areas twice daily. Discontinue when lesions resolve. For adults, use 0.03% or 0.1%; 0.1% is not indicated for children.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between ELIDEL and PROTOPIC in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. ELIDEL is classified as Category C. FDA Pregnancy Category C. Systemic exposure is minimal after topical application, but animal studies have shown developmental toxicity. No adequate human studies; risk cannot be ex. PROTOPIC is classified as Category C. Pregnancy Category C. Animal studies have shown embryotoxicity and teratogenicity at systemic exposures below human therapeutic levels. No adequate human studies in pregnant women.. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.