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(Date of issue: February 2018, Version: 1.2)

This is a UKTIS monograph for use by health care professionals. For case-specific advice please contact UKTIS on 0344 892 0909. To report an exposure please download and complete a pregnancy reporting form. Please encourage all women to complete an online reporting form.


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 exposure to BZ poses to a developing fetus, although maternal toxicity is likely to be a major determinant of 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. Additional fetal monitoring may be warranted on a case-by-case basis; discussion with UKTIS is recommended for all cases of gestational exposure.

This document is regularly reviewed and updated. Only use full UKTIS monographs downloaded directly from TOXBASE.org to be sure you are using the most up-to-date version. The summaries of these monographs are openly available on UKTIS.org.

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 health care professionals at www.toxbase.org.

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.

Disclaimer: Every effort has been made to ensure that this monograph was accurate and up-to-date at the time of writing, however it cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes of the measures recommended. The final decision regarding which treatment is used for an individual patient remains the clinical responsibility of the prescriber. This material may be freely reproduced for education and not for profit purposes within the UK National Health Service, however no linking to this website or reproduction by or for commercial organisations is permitted without the express written permission of this service. This document is regularly reviewed and updated. Only use UKTIS monographs downloaded directly from TOXBASE.org or UKTIS.org to ensure you are using the most up-to-date version.