Triderm® - (IR): composition and pharmaceutical form
The medicine comes in two topical forms — cream and ointment. One gram of cream or ointment contains 0.5 mg of betamethasone as the dipropionate, 10 mg of clotrimazole and 1 mg of gentamicin as the sulfate.
The cream contains cetostearyl alcohol, which can cause a local skin reaction such as contact dermatitis, and propylene glycol, which may irritate the skin. The choice between cream and ointment depends on the nature of the lesions and is made by the doctor.
How Triderm® - (IR) works
The medicine's action is made up of three parts. Betamethasone dipropionate belongs to the potent corticosteroids: applied to the skin it relieves inflammation and itching quickly and for a long time and constricts the blood vessels. Gentamicin is an aminoglycoside antibiotic with a broad antibacterial spectrum.
Clotrimazole is an imidazole derivative with a broad antifungal spectrum: it acts on the fungal cell wall and inhibits the development of the agents of skin mycoses. Resistance to clotrimazole is rare — it has been described in Candida guilliermondi, whereas repeated exposure of Candida albicans and Trichophyton mentagrophytes produced no resistant strains.
Indications
The cream and the ointment are used for the symptomatic treatment of inflammatory skin diseases that respond to corticosteroids, when they are complicated by a secondary infection caused by organisms sensitive to gentamicin and clotrimazole.
Clotrimazole has proved effective in the topical treatment of fungal involvement of the inguinal folds, the perineum, the feet and glabrous skin: it acts on Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum and Microsporum canis, and also in candidiasis caused by Candida albicans and pityriasis versicolor caused by Malassezia furfur. Sensitive to gentamicin are group A streptococci, Staphylococcus aureus including some penicillinase-producing strains, and gram-negative bacteria — Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris, Klebsiella pneumoniae.
Method of use and dosage
A thin layer of cream or ointment is applied to the affected areas of skin and the surrounding healthy skin twice a day — morning and evening. The medicine must be applied regularly. Improvement, in the form of the redness and itching disappearing, usually comes in the first 3–5 days of treatment.
| Situation | Duration and rules |
|---|---|
| Fungal involvement of the inguinal folds, the perineum and glabrous skin, candidiasis | A 2-week course; if there is no improvement within a week, review the diagnosis |
| Fungal involvement of the feet | A 4-week course; if there is no improvement within two weeks, review the diagnosis |
| The ointment in other indications | The duration depends on the extent and location of the lesions and on the response to treatment; if there is no improvement after 3–4 weeks the diagnosis is reviewed |
| Children under 12 | Use is not recommended |
If symptoms persist after 2 weeks of treating fungal skin involvement and candidiasis, or after 4 weeks of treating mycosis of the feet, the medicine is withdrawn and another treatment is used. Using the product for more than 4 weeks is not recommended.
Contraindications
The medicine is not used in the following cases:
- hypersensitivity to betamethasone dipropionate, clotrimazole or gentamicin, to other corticosteroids, imidazole derivatives, aminoglycoside antibiotics or to any excipient;
- viral skin lesions, for example chickenpox or herpes;
- rosacea and acne vulgaris;
- primary bacterial and fungal skin infections;
- application to wounds and damaged skin;
- application to the skin of the face and in the area of the anus and the genitals;
- perioral dermatitis;
- prolonged use.
Special warnings and precautions
Both systemically acting substances — the corticosteroid and gentamicin — are absorbed through the skin, so systemic undesirable effects are also possible: suppression of adrenal cortex function from betamethasone, and oto- and nephrotoxicity from gentamicin, especially in people with impaired kidney function. Occlusive dressings increase absorption, so applying it to a large body surface, in large amounts and under a dressing should be avoided. If irritation, an allergic reaction or a secondary infection appears, the medicine is withdrawn and appropriate treatment prescribed.
- the product must not be applied in the eyes, around them or on mucous membranes;
- prolonged topical use promotes the growth of strains resistant to gentamicin and other aminoglycosides; cross-allergy to aminoglycoside antibiotics has been described;
- particular caution is needed in psoriasis: topical corticosteroids in this disease can be dangerous because of the rebound when tolerance develops, the risk of generalised pustular psoriasis and general toxic action when skin integrity is broken;
- in children suppression of the hypothalamic-pituitary-adrenal axis occurs more often than in adults because of the greater ratio of skin surface to body weight; Cushing's syndrome, slowed growth, insufficient weight gain and raised intracranial pressure have been described;
- adrenal insufficiency is indicated by a low plasma cortisol and the absence of a response to ACTH stimulation, and raised intracranial pressure by a bulging fontanelle, headache and bilateral papilloedema.
Drug interactions
No interactions of the medicine with other medicinal products are known.
That does not remove the general precautions: any topical products you already apply to the same areas of skin are worth telling the doctor about, since using several preparations at once may increase irritation.
Pregnancy and breastfeeding
There are no data on the safety of use in pregnant women, but corticosteroids and gentamicin are known to be capable of absorption through the skin. Using the medicine during pregnancy is possible only when the expected benefit to the mother outweighs the possible risk to her, the foetus or the newborn. Since animal studies have revealed a teratogenic effect of potent corticosteroids, treatment during pregnancy must be short and limited to a small area of skin.
Whether the active substances are absorbed after topical application in amounts sufficient to pass into breast milk is unknown. The doctor decides together with the patient whether to stop breastfeeding or to forgo the medicine, based on its importance for the mother. The product is not applied to the skin of the breasts while breastfeeding.
Adverse effects
The most frequent are local reactions: burning, redness, weeping and itching. The undesirable effects known for each of the components in topical use are also possible.
- from betamethasone dipropionate — burning, itching, irritation, dryness of the skin, inflammation of the hair follicles, excessive hair growth, steroid acne;
- from betamethasone dipropionate — skin depigmentation, perioral dermatitis, allergic contact dermatitis, maceration of the skin, secondary infections, skin atrophy, striae and miliaria;
- when betamethasone is absorbed into the blood — systemic effects typical of corticosteroids, above all with prolonged use, application to a large surface and in children;
- from clotrimazole — redness, burning, formation of blisters, peeling, oedema, itching, urticaria and general irritation of the skin;
- from gentamicin — skin irritation with redness and itching, which usually does not require stopping treatment;
- hypersensitivity reactions — if they appear, treatment is stopped immediately.
Overdose
Excessive or prolonged topical use of corticosteroids can suppress the hypothalamic-pituitary-adrenal axis and cause secondary adrenal insufficiency, as well as systemic corticosteroid effects including Cushing's syndrome. Excessive or prolonged topical use of gentamicin can lead to the appearance of resistant bacterial strains and also to hearing and kidney damage. Overdose of clotrimazole in topical use is unlikely: after six hours under an occlusive dressing, isotope-labelled clotrimazole was not detectable in the serum of study participants.
Treatment is symptomatic. Acute manifestations of corticosteroid excess are transient; if necessary the electrolyte balance is corrected and, in chronic poisoning, the corticosteroid dose is reduced gradually. If the growth of non-susceptible organisms begins, the medicine is withdrawn and suitable treatment prescribed.
How to get a prescription for Triderm® - (IR) online
Combined topical products with a corticosteroid and an antibiotic are dispensed on prescription: the doctor must confirm that the inflammation really is complicated by infection and determine the length of the course.
During the online consultation the doctor will go through the nature of the lesions and the previous treatment and, if there are no contraindications, issue an electronic prescription — the medicine can be collected at a pharmacy with its code.
