Dibutyl square ester (sadbe)

Author: Prof. Dr. med. Peter Altmeyer

Last updated on: 29.10.2020

Synonym(s)

SADBE; Squaric acid dibutyl ester

Obligatory contact sensitizing, therapeutically effective hazardous substance without approval as a drug (orphan drug).

Topical immunotherapy of alopecia areata, especially severe forms including alopecia areata totalis

Dermatology

Physiological swelling of the mammary glands in about half of all boys during puberty. S.a.u. Gynecomastia.

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Not for pregnant women or mothers who are breastfeeding (contraindicated for formal drug law reasons).

Cave! There are no commercial products. The attending physician bears full responsibility for the therapy and its NW!

One-time application of a 2% SADBE solution on one side of the head to create a contact sensitization: 2-7 days after application, a (desired) burning and itching as well as an eczema reaction occurs. Patients must be instructed not to wash the hair for at least 48 hours after application and to observe sun protection measures of the treated localities.
Next application of a highly diluted SADBE solution (0.001%) 14 days after sensitization, then once a week. Slowly increase the concentration. Titration to a dosage (individually very different) that causes an inflammatory reaction with redness and itching the next day and heals with scaling. Treatment once/week for initially 6-12 months, possibly years. Effect begins after approx. 10 applications. Accompanying therapy with steroid-free creams (e.g. Dermatop base cream etc.). Cave! Treatment should be carried out on one side of the skin to prevent spontaneous remission.

Application of a 2% SADBE solution to an area of 1 cm2 on the inner forearm to trigger a local inflammatory reaction (repeat once if necessary; failure in 1-3% of patients).
Application of a 0.1% SADBE solution to warts to be treated (exception: 2% SADBE solution on the soles of the feet!) and covering with adhesive bandage for at least 48 hours. After the local reaction has subsided, keratolysis (e.g. Guttaplast plaster) and curettage. Repeat the therapy every 1-4 weeks with increasing SADBE dosages, depending on the strength of the local reaction: 0.25%; 0.5%, 1.0%; 2.0%; 3.0%; 4.0%; maximum 6%.

Severe, sometimes generalized scattering contact allergic eczema; urticaria; erythema exsudativum multiforme; depigmentations.

Children under 10 years of age (contraindicated for formal drug law reasons; studies in children are not known)

Dibutyl square ester is thermolabile and must be stored frozen (< -20 °C).

Buckley DA et al (2001) The therapeutic use of topical contact sensitizers in benign dermatoses. Br J Dermatol 145: 385-405
Morita K et al (2002) Seventeen cases of alopecia areata: combination of SADBE topical immunotherapy with other therapies. J Dermatol 29: 661-664
Rokhsar CK et al (1998) Efficacy of topical sensitizers in the treatment of alopecia areata. J Am Acad Dermatol 39: 751-761
Shapiro J (1993) Topical immunotherapy in the treatment of chronic severe alopecia areata. Dermatol Clin 11: 611-617
Silverberg NB et al (2000) Squaric acid immunotherapy for warts in children. J Am Acad Dermatol 42: 803-808
Tosti A et al (2003) Lentiginous eruption due to topical immunotherapy. Arch Dermatol 139: 544-545