Carbamate teratogenicity

Carbamate esters of zinc, zineb, and ziram are carcinogenic and teratogenic in animals, but this is attributed to the action of the carbamate esters and not to zinc (Elinder 1986). Results of studies with small mammals showed zinc to be cocarcinogenic with 4-nitroquinoline-N-oxide on oral cancer, and with N-ethyl-N-nitrosourea on brain cancer (Leonard and Gerber 1989). 

Woo, Y.-T. (1983) Carcinogenicity, mutagenicity and teratogenicity of carbamates, fhiocarbamates and related compounds an overview of structure-activity relationships and environmental concerns. Environ. Carcinog. Ecotoxicol. Rev., Cl (1), 97-133. 

A number of benzimidazoles exist as prodrugs their anthelminthic activity is due to the fact that they are metabolized in the animal body to the biologically active benzimidazole carbamate nucleus. Due to their relatively slower excretion rates, the newer insoluble benzimidazoles have fairly long withdrawal periods for edible tissues and milk in contrast to the less effective and more rapidly excreted thiabendazole analogues. Strict compliance with withdrawal periods is always necessary because of the potentially toxic and teratogenic effects of some of the benzimidazoles and their metabolites. 

Several related analogues of the benzimidazoles are also anthelmintics including the imidazopyridine (5), tioxidazole (6), and the prodrugs, thiophanate (7) and febantel (8). However, although the benzimidazoles and related anthelmintics have proved a rich source of drugs, there is now evidence of widespread resistance to them, particularly in sheep parasites. Moreover, some benzimidazole carbamates are suspect in respect of teratogenicity and mutagenicity. 

Carbamate pesticides are used as (1) insecticides, (2) fungicides and (3) herbicides. Insecticides are generally derived from carbamic acid fungicides, from thiocarbamic acid. The herbicide carbamates are a more complex class of compounds. Tables 21 and 22 list some commercial carbamate pesticides in approximate order of decreasing toxicity. It should be noted that the relative classification of highly and moderately toxic is no measure of the relative carcino-, muta- or teratogenicities of these carbamates, since it is based solely on acute LD q data (Morgan, ref. 20). 

In addition to the most popular chlorophenoxy herbicides, the group includes a variety of other chemical classes—e.g., amides, bipyridyls, carbamates, dinitrophenols, substituted ureas and triazines. Most of the chemicals tested are animal teratogens, as are many of the fungicides in this miscellaneous group (ref. 185. p. 578 and 586). 

Questionable carcinogen with experimental carcinogenic and tumorigenic data. An experimental teratogen. Other experimental reproductive effects. Human mutation data reported. See also ZINC COMPOUNDS and CARBAMATES. Severe irritant to eyes, nose, and throat. When heated to decomposition it emits very toxic fiimes of NOx and SOx. 

SAFETY PROFILE A poison via intraperitoneal route. Moderately toxic via subcutaneous route. Experimental teratogenic effects. Questionable carcinogen with experimental neoplastigenic data. Mutation data reported. See also CARBAMATES. When heated to decomposition it emits toxic fumes of NO. ... 

SAFETY PROFILE Many carbamates are poisons or moderately toxic, and some are carcinogenic, teratogenic, or mutagenic. 

Carbaryl, semicarbazide hydrochloride, n-propyl carbamate, Maneb, Zineb, Ferbam, and Thiram are experimental teratogens. 

SAFETY PROFILE Human poison by unspecified routes. Moderately toxic to humans and experimentally by ingestion. Experimental poison by intravenous, intraperitoneal, and subcutaneous routes. An experimental teratogen. Human systemic effects by ingestion coma, blood pressure decrease, regional or general arteriolar constriction, dyspnea, cyanosis, respiratory depression, nausea or vomiting, and allergic skin dermatitis. Experimental reproductive effects. Mutation data reported. Implicated in aplastic anemia. Used as a tranquilizer. When heated to decomposition it emits toxic fumes of NOx. See also CARBAMATES. 

SAFETY PROFILE Mildly toxic by ingestion. An experimental teratogen. When heated to decomposition it emits toxic fumes of SO and NOx. A fungicide used to control athlete s foot. See also ESTERS and CARBAMATES. 

Phosphoric acid esters and carbamates Nausea convulsions elevated blood pressure rapid heartbeat impaired vision diarrhoea pulmonaiy oedema asthma attacks loss of consciousness respiratory paralysis teratogenic Very good absorption through the lungs, digestive system and skin Insecticides warfare agents... 

A highly toxic substance by ingestion, and possibly by most other routes of exposure moderately toxic by inhalation and skin contact cholinesterase inhibitor toxic effects are similar to those of other carbamate pesticides and include excessive salivation, lacrimation, slow heart rate, blurred vision, twitching of muscle and lack of coordination, nausea, weakness, diarrhea and abdominal pain oral intake of probably 1.5-3 g could be fatal to adult humans a teratogenic substance, producing adverse reproductive effects in experimental animals. 

Mildly toxic in rodent by ingestion, inhalation, and absorption through skin large doses can produce effects of carbamate poisoning teratogenic and mutagenic effects reported carcinogenic potential not known mild skin irritant. 

---