Usage
Tacalcitol is prescribed for the topical treatment of mild to moderate plaque psoriasis in adults and children over 12 years of age. It falls under the pharmacological classification of antipsoriatics and, more specifically, is a vitamin D analog. Tacalcitol works by binding to vitamin D receptors in skin cells (keratinocytes), which inhibits excessive cell proliferation and promotes cell differentiation. This helps to normalize the rate of skin cell production and reduce inflammation associated with psoriasis.
Alternate Names
Tacalcitol is also known by the brand name Curatoderm®.
How It Works
Pharmacodynamics: Tacalcitol exerts its antipsoriatic effect by binding to and activating vitamin D receptors in keratinocytes. This leads to a reduction in cell proliferation, normalization of keratinocyte differentiation, and suppression of inflammatory responses within the skin.
Pharmacokinetics: When applied topically, less than 0.5% of tacalcitol is absorbed through the skin, minimizing systemic effects. The absorbed drug is extensively bound to plasma proteins, primarily vitamin D binding protein. It is metabolized primarily to 1-α, 24, 25 (OH)3 vitamin D3 and excreted mainly in the urine.
Mode of Action: Tacalcitol’s mode of action involves binding to the vitamin D receptor, a nuclear transcription factor that modulates the expression of genes involved in cell growth, differentiation, and inflammation. It inhibits the proliferation of keratinocytes by regulating cell cycle progression and promoting differentiation towards a more normal phenotype. This reduces the excessive thickening and scaling characteristic of psoriatic plaques. Additionally, Tacalcitol modulates immune responses in the skin, further contributing to its anti-inflammatory effects.
Elimination: Tacalcitol is primarily metabolized in the liver and excreted in the urine.
Dosage
Standard Dosage
Adults:
Apply a thin layer of Tacalcitol 0.004% ointment or lotion to affected areas once daily, preferably at bedtime. The maximum daily dose is 10 grams of ointment or 10 mL of lotion (equivalent to 200 mcg of tacalcitol). The maximum weekly dose is 280 mcg (e.g. 40g of ointment plus 30 ml of lotion per week). Treatment duration may range from several weeks to 18 months, depending on the severity and location of the lesions.
Children (over 12 years):
Similar dosing as adults, but the treated skin area should not exceed 15% of the body surface area. Pediatric use in children under 12 is not recommended due to limited safety and efficacy data.
Special Cases:
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Elderly Patients: Use with caution, similar to adults, monitoring for potential hypercalcemia.
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Patients with Renal Impairment: Use with caution in patients with severe renal impairment. Monitor serum calcium levels.
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Patients with Hepatic Dysfunction: Use with caution in severe hepatic impairment.
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Patients with Comorbid Conditions: No specific dose adjustment is necessary for patients with comorbid conditions like diabetes or cardiovascular disease, but careful monitoring is advised.
Clinical Use Cases
Tacalcitol is not systemically administered and therefore not indicated for clinical settings like intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. It is exclusively for topical application in the treatment of psoriasis.
Dosage Adjustments
Dose adjustments may be necessary in patients with renal or hepatic impairment based on individual patient factors and clinical judgment. Regular monitoring of serum calcium levels is recommended.
Side Effects
Common Side Effects:
- Itching
- Burning sensation at the application site
- Skin irritation (redness, dryness)
Rare but Serious Side Effects:
- Hypercalcemia (high blood calcium)
- Allergic reactions (rash, swelling, difficulty breathing)
- Worsening of psoriasis
Long-Term Effects:
Potential long-term effects of tacalcitol are not well-established. Regular monitoring for hypercalcemia and skin irritation is recommended.
Adverse Drug Reactions (ADR):
Clinically significant ADRs include hypercalcemia and hypersensitivity reactions, which require prompt medical attention.
Contraindications
- Hypersensitivity to tacalcitol
- Hypercalcemia or other disorders of calcium metabolism
- Severe renal or hepatic impairment
- Generalized pustular or erythrodermic psoriasis
Drug Interactions
- Other vitamin D analogs or supplements: Concurrent use may increase the risk of hypercalcemia.
- Thiazide diuretics: May increase the risk of hypercalcemia.
- UV therapy: Tacalcitol can enhance the effects of UV therapy and shorten the treatment duration.
Pregnancy and Breastfeeding
Tacalcitol’s safety during pregnancy has not been fully established. It is generally considered safe to use during breastfeeding due to low systemic absorption, but the infant’s skin should not come into contact with treated areas.
Drug Profile Summary
- Mechanism of Action: Binds to Vitamin D receptors in keratinocytes to inhibit proliferation and induce differentiation, reducing inflammation and scaling.
- Side Effects: Itching, burning, skin irritation, rarely hypercalcemia and allergic reactions.
- Contraindications: Hypersensitivity, hypercalcemia, severe renal/hepatic impairment, pustular/erythrodermic psoriasis.
- Drug Interactions: Other Vitamin D analogs, thiazide diuretics, UV therapy.
- Pregnancy & Breastfeeding: Use with caution during pregnancy; generally safe during breastfeeding with precautions.
- Dosage: Apply thinly once daily, maximum 10g ointment/10ml lotion daily.
- Monitoring Parameters: Serum calcium levels, especially in patients with renal impairment.
Popular Combinations
While Tacalcitol can be combined with other treatments, it is often used as monotherapy. Combination with topical corticosteroids may be used for short periods under strict medical supervision.
Precautions
- General Precautions: Avoid contact with eyes. Do not apply to broken skin.
- Pregnant Women: Use only if clearly needed after consulting with a physician.
- Breastfeeding Mothers: Safe with precautions – avoid applying to nipples and ensure infant’s skin does not contact treated area.
- Children & Elderly: Use with caution, especially in those with renal impairment. Monitor calcium levels.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Tacalcitol?
A: Adults and children over 12: Apply a thin layer of 0.004% ointment/lotion once daily to affected areas, maximum 10g/10ml daily.
Q2: What are the common side effects?
A: Itching, burning, skin irritation.
Q3: Is Tacalcitol safe during pregnancy?
A: Safety not fully established, consult a doctor.
Q4: Can I use Tacalcitol while breastfeeding?
A: Generally considered safe with precautions (avoid nipples, infant contact).
Q5: How does Tacalcitol work?
A: Binds to vitamin D receptors to inhibit keratinocyte proliferation and promote differentiation.
Q6: What skin conditions is Tacalcitol used for?
A: Plaque psoriasis.
Q7: Can Tacalcitol be used on the face?
A: Yes, but avoid contact with eyes.
Q8: How long does it take for Tacalcitol to work?
A: Improvement is usually seen within a few weeks, but full effects can take several months.
Q9: Are there any drug interactions I should be aware of?
A: Yes, other vitamin D analogues, thiazide diuretics, and UV therapy.
