Cantharidin Chemical formula
Synonyms: Cantaridina. Hexahydro-3aα,7aα-dimethyl-4β,7β-epoxyisobenzofuran-1,3-dione.
Cyrillic synonym: Кантаридин.

💊 Chemical information

Chemical formula: C10H12O4 = 196.2.
CAS — 56-25-7.

💊 Adverse Effects and Treatment

The adverse effects of cantharidin, a protective exudate produced by blistering beetles (see under Cantharides above), are a result of its irritant and vesicant properties and may occur after exposure to preparations of cantharidin or to the beetle itself. Cantharidin produces blistering of mucous membranes. After ingestion of cantharidin there is burning pain in the throat and stomach, difficulty in swallowing, nausea, vomiting, haematemesis, abdominal pain, diarrhoea (sometimes bloody), tenesmus, renal pain, frequent micturition, dysuria, priapism, haematuria, proteinuria, renal failure, severe hypotension, and circulatory failure. Severe gastrointestinal disturbances can produce significant morbidity. Oral doses of cantharidin ranging from 10 to 80 mg have been lethal, although there have been reports of survival after doses up to 175 mg. Cantharidin is lipid soluble and oral bioavailability is increased in the presence of fatty substances. Dermatological exposure may produce dermatitis, blisters, and ulceration, although symptoms may not appear until several hours later. Significant dermal exposure can give rise to systemic toxicity. Keratoconjunctivitis, iritis, and oedema may result from contact with the eyes or surrounding tissues. Cantharidin has been abused as a sex stimulant. Treatment of cantharidin poisoning is largely supportive. Emesis must be avoided following oral ingestion because of the severe irritant effect of cantharidin on mucous membranes. Activated charcoal has been tried, although it is not certain whether it binds to cantharidin.


1. Hundt HKL, et al. Post-mortem serum concentration of cantharidin in a fatal case of cantharides poisoning. Hum Exp Toxicol 1990; 9: 35–40
2. Polettini A, et al. A fatal case of poisoning with cantharidin. Forensic Sci Int 1992; 56: 37–43
3. Karras DJ, et al. Poisoning from "Spanish fly" (cantharidin). Am J Emerg Med 1996; 14: 478–83
4. Tagwireyi D, et al. Cantharidin poisoning due to "Blister beetle" ingestion. Toxicon 2000; 38: 1865–9.

💊 Uses and Administration

Cantharidin is obtained from cantharides or mylabris (see under Cantharides, above). Cantharidin has vesicant activity and a solution of 0.7% in flexible collodion is applied for the removal of warts and molluscum contagiosum. Preparations of cantharides and cantharidin have also been used externally as rubefacients and counter-irritants. Owing to the intensely irritating nature of cantharidin it should not be taken internally. Also it should not be applied over large surfaces because of the risk of absorption. Preparations of cantharides and cantharidin were formerly promoted for hair loss but their use in cosmetic products is now prohibited in the UK by law.

Molluscum contagiosum.

1. Silverberg NB, et al. Childhood molluscum contagiosum: experience with cantharidin therapy in 300 patients. J Am Acad Dermatol 2000; 43: 503–7
2. Moed L, et al. Cantharidin revisited: a blistering defense of an ancient medicine. Arch Dermatol 2001; 137: 1357–60
3. Ross GL, Orchard DC. Combination topical treatment of molluscum contagiosum with cantharidin and imiquimod 5% in children: a case series of 16 patients. Australas J Dermatol 2004; 45: 100–2
4. Hanna D, et al. A prospective randomized trial comparing the efficacy and adverse effects of four recognized treatments of molluscum contagiosum in children. Pediatr Dermatol 2006; 23: 574–9.

💊 Preparations

Proprietary Preparations

Canad.: Canthacur; Cantharone. Multi-ingredient: Canad.: Canthacur-PS; Cantharone Plus.
Published February 05, 2019.