Usage
Selenium sulphide is prescribed for the treatment of seborrheic dermatitis (dandruff), tinea versicolor (a fungal skin infection), and pityriasis capitis. Its pharmacological classification is antifungal agent. Selenium sulphide slows the growth of skin cells, including fungal cells like Malassezia yeasts, reducing the scaling and inflammation seen in these conditions.
Alternate Names
While “selenium sulphide” is the generic name, it’s marketed under brand names like Selsun Blue, Selsun, Head & Shoulders Intensive Treatment, and others. There are no significant international variations in the name.
How It Works
Pharmacodynamics: Selenium sulphide works by slowing the turnover of epidermal cells, which helps to reduce scaling and flaking associated with dandruff and other skin conditions. It also has some antifungal properties, which are particularly helpful in managing conditions like tinea versicolor. The exact mechanism of action is unclear but it is believed that it may also block certain enzymes important for epithelial tissue growth.
Pharmacokinetics: Primarily applied topically, selenium sulphide has minimal systemic absorption when used as directed on intact skin. However, absorption can increase if applied to broken or inflamed skin. The limited absorbed drug is excreted primarily through the kidneys. The exact metabolic pathways are not well-defined. There’s no significant receptor binding, enzyme inhibition, or neurotransmitter modulation known for topical selenium sulphide.
Dosage
Standard Dosage
Adults:
- Dandruff/Seborrheic Dermatitis: Apply 5-10 mL of 2.5% lotion or 2.25% shampoo twice weekly for 2 weeks initially, then reduce to once a week, every 2 weeks, or even monthly for maintenance, as needed. 1% preparations are available over-the-counter and can be used more frequently if necessary.
- Tinea Versicolor: Apply 2.5% lotion to affected areas once daily for 7 days.
Children:
- Dandruff/Seborrheic Dermatitis: Children older than 2 years can use the 1% lotion or shampoo once or twice weekly. The 2.5% lotion should only be used under a physician’s recommendation and supervision.
- Tinea Versicolor: Children older than 2 years can use the 2.5% lotion once daily for 7 days.
Special Cases:
- Elderly Patients: No specific dosage adjustments are typically necessary.
- Patients with Renal Impairment: No specific dosage adjustments are typically necessary due to minimal systemic absorption.
- Patients with Hepatic Dysfunction: No specific dosage adjustments are typically necessary due to minimal systemic absorption.
- Patients with Comorbid Conditions: Use with caution on broken or inflamed skin.
Clinical Use Cases
Selenium sulphide is not indicated for intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its use is limited to topical treatment of dermatological conditions.
Dosage Adjustments
No specific adjustments are routinely necessary, but use cautiously on broken or inflamed skin.
Side Effects
Common Side Effects
- Skin irritation (burning, itching, stinging)
- Dry skin
- Oily or dry hair/scalp
- Temporary hair loss
- Hair discoloration
Rare but Serious Side Effects
Severe skin reactions (blistering, peeling) should prompt discontinuation of the medication and medical attention. Although systemic absorption is minimal, high exposure can lead to headache, nausea, vomiting, garlic odor of the breath, and metallic taste.
Long-Term Effects
No specific long-term side effects are typically associated with topical use as directed.
Adverse Drug Reactions (ADR)
Severe allergic reactions are rare.
Contraindications
Hypersensitivity to selenium sulphide. Avoid application to broken or inflamed skin.
Drug Interactions
Avoid concurrent use of other topical medications on the same area unless directed by a physician.
Pregnancy and Breastfeeding
- Pregnancy: Topical selenium sulphide is generally considered safe for treating dandruff on the scalp during pregnancy. However, its safety for treating tinea versicolor during pregnancy hasn’t been established due to potential systemic absorption.
- Breastfeeding: Excretion in breast milk is unknown. Use with caution.
Drug Profile Summary
- Mechanism of Action: Slows epidermal cell turnover, some antifungal activity.
- Side Effects: Skin irritation, hair discoloration, dry skin, increased hair loss.
- Contraindications: Hypersensitivity to selenium sulphide.
- Drug Interactions: Avoid concurrent use of other topical medications on the same area.
- Pregnancy & Breastfeeding: Consult a physician. Use with caution when treating tinea versicolor in pregnant or breastfeeding women.
- Dosage: See section above.
- Monitoring Parameters: Monitor for local skin reactions.
Popular Combinations
Selenium sulphide is not typically used in combination with other drugs for topical applications.
Precautions
- Avoid contact with eyes and mucous membranes.
- Rinse thoroughly after application.
- Discontinue if irritation occurs.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Selenium Sulphide?
A: Please refer to the detailed dosage guidelines outlined above, covering standard dosage, children and special cases.
Q2: How does Selenium Sulphide work?
A: Selenium sulphide inhibits cell growth in the epidermis, reducing cell turnover, flaking, and scaling. It has antifungal properties, specifically against Malassezia yeasts.
Q3: Is Selenium Sulphide safe to use during pregnancy or while breastfeeding?
A: While generally safe for dandruff on the scalp during pregnancy, its safety hasn’t been fully established for treating tinea versicolor due to potential absorption. Consult a physician before using during pregnancy or while breastfeeding.
Q4: What are the common side effects of Selenium Sulphide?
A: Common side effects include skin irritation (burning, itching, stinging), dry skin, oily or dry hair/scalp, temporary hair loss, and hair discoloration.
Q5: How long does it take for Selenium Sulphide to work?
A: Improvement in dandruff and seborrheic dermatitis is typically seen within a few weeks of regular use. Tinea versicolor usually responds within 7 days of treatment.
Q6: Can Selenium Sulphide be used on the face?
A: It’s generally advised to avoid using selenium sulphide on the face due to the risk of irritation, especially around the eyes and mucous membranes.
Q7: Are there any drug interactions with Selenium Sulphide?
A: Avoid using other topical medications on the same area as selenium sulphide unless advised by a physician, as it can affect absorption or effectiveness.
Q8: What should I do if I experience an allergic reaction to Selenium Sulphide?
A: Discontinue use immediately and seek medical advice. Allergic reactions can manifest as skin rash, itching, hives, or swelling of the face, lips, tongue, or throat.
Q9: Can Selenium Sulphide permanently discolor hair?
A: Hair discoloration is usually temporary and can be minimized by thoroughly rinsing the hair after each application.
Q10: Is Selenium Sulphide safe for children?
A: The 1% preparations are generally considered safe for children over 2 years old. The 2.5% products may be used in children under physician supervision, if deemed necessary.
