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Date of issue: April 2023, Version: 2.0

BZ (Agent 15) is a glycolic anticholinergic compound with structural and pharmacological similarities to atropine and hyoscine. It acts as a competitive inhibitor of the acetylcholinergic (muscarinic) receptor in the cholinergic nervous system. Exposure results in inhibition of the parasympathetic nervous system with development of anticholinergic symptoms. BZ was originally developed as a non-lethal incapacitating chemical weapon by the US army, but is now primarily used in cholinergic nervous system research and pharmaceutical manufacturing.

There are no published data regarding maternal exposure to BZ, or guidelines for the treatment of BZ poisoning during pregnancy. It is therefore not currently possible to offer an evidence-based assessment of the risk that maternal BZ exposure poses to a developing fetus, although maternal toxicity is likely to be a major determinant of fetal risk. Where treatment is required, management of the pregnant patient should be the same as for the non-pregnant patient.

Exposure to BZ at any stage in pregnancy would not usually be regarded as medical grounds for termination of pregnancy. However, other risk factors may be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case specific risk assessments. Given the lack of human pregnancy data and the broad anticholinergic effects of BZ, additional fetal monitoring may be warranted on a case-by-case. Discussion with UKTIS is recommended for all cases of gestational exposure.

This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to NHS health care professionals who are logged in.

If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.

If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.

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