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(Date of issue: March 2016, Version: 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.


Acetazolamide is a carbonic anhydrase inhibitor indicated in the treatment of glaucoma, the abnormal retention of fluids and epilepsy. Unlicensed indications also include altitude sickness prophylaxis and the management of idiopathic intracranial hypertension.

Animal studies have identified increased risks of limb and axial skeletal anomalies following administration of doses of acetazolamide approximately 70 times the recommended human dose during gestation. The available human exposure data mainly consist of case reports/series and a small number of cohort studies which detail the outcomes of more than 1,000 acetazolamide-exposed pregnancies. However, only 83 of these pregnancies have been exposed in the first trimester. The congenital malformation data are therefore highly limited, and although there is no signal that acetazolamide is a major human teratogen, the data are too limited and the number of first trimester exposed infants is too small to exclude a more subtle effect on the developing fetus.

Data concerning the risk of spontaneous abortion, low birth weight, preterm delivery and neurodevelopmental impairment are both limited and confounded. Additional controlled studies are required before reliable conclusions regarding the risk of these outcomes can be provided. A number of neonatal complications, including dehydration, lethargy, breathing difficulties, metabolic acidosis, hypoglycaemia, hyperbilirubinaemia, hypocalcaemia, hypomagnesaemia and neonatal death have been described in exposed infants. However, the contribution of the underlying maternal illness, concomitant exposures and other clinical risk factors to these events is currently unclear. Nonetheless, metabolic acidosis is a recognised adverse effect of acetazolamide treatment and as case reports have described acidosis in neonates following exposure in later pregnancy, neonatal monitoring may be advised where use has occurred in the weeks before delivery. No studies have been located which investigate the risk of cancer following intrauterine acetazolamide exposure.
Exposure to acetazolamide at any stage in pregnancy would not usually be regarded as medical grounds for termination of pregnancy or any additional fetal monitoring. 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.

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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 or to ensure you are using the most up-to-date version.