Nifedipine and pulmonary oedema when used in pregnancy

Health professionals are advised that the Product Information (PI) for nifedipine has been updated to provide new information about the risk of acute pulmonary oedema when used as a tocolytic agent (inhibiting myometrial smooth muscle contractions) for the treatment of preterm labor in pregnancy.

Nifedipine is a calcium channel blocker that is marketed in Australia under several brand names, including Adalat, Adefin, Addos and APO-Nifedipine.

Nifedipine is indicated for:

• the management of chronic stable angina pectoris and vasospastic angina pectoris (Prinzmetal's angina, variant angina) due to coronary heart disease
• the treatment of hypertension.

Nifedipine is contraindicated in pregnancy and during lactation. However, the Therapeutic Goods Administration (TGA) has received four adverse event reports involving off-label use in pregnancy.

The 'Fertility, pregnancy and lactation' section of the nifedipine PI (section 4.6) has been updated to include the following information:

'Acute pulmonary oedema has been observed when calcium channel blockers, among others nifedipine (primarily in [immediate release] formulation), have been used as a tocolytic agent during pregnancy, especially in cases of multiple pregnancy (twins or more), with the intravenous route and/or concomitant use of beta-2 agonists.'

The TGA recommends that off-label use only be considered when other options are unavailable, exhausted, not tolerated or unsuitable. Prescribers should discuss the risks and benefits of the proposed treatment with the patient and/or their carers so that they are capable of providing informed consent. Additionally, the treatment, including its effectiveness and potential adverse events, should be closely monitored.

What to report? You don't need to be certain, just suspicious!

The TGA encourages the reporting of all suspected adverse reactions to medicines, including vaccines, over-the-counter medicines, herbal, traditional or alternative remedies.

We particularly request reports of:

• all suspected reactions to new medicines (look for the Black Triangle in PI and CMI documents - this symbol identifies medicines that are new or being used differently)
• all suspected medicines interactions
• suspected reactions causing death, admission to hospital or prolongation of hospitalisation, increased investigations or treatment, or birth defects.

Reports may be submitted:

• online at www.tga.gov.au
• by fax to 02 6232 8392
• by email to ADR.Reports@tga.gov.au

For more information about reporting, visit www.tga.gov.au or contact the TGA's Pharmacovigilance and Special Access Branch ADR.Reports@tga.gov.au.

Disclaimer

Medicines Safety Update is aimed at health professionals. It is intended to provide practical information to health professionals on medicine safety, including emerging safety issues. The information in Medicines Safety Update is necessarily general and is not intended to be a substitute for a health professional's judgment in each case, taking into account the individual circumstances of their patients. Reasonable care has been taken to ensure that the information is accurate and complete at the time of publication. The Australian Government gives no warranty that the information in this document is accurate or complete, and shall not be liable for any loss whatsoever due to negligence or otherwise arising from the use of or reliance on this document.

© Commonwealth of Australia 2021

This work is copyright. You may reproduce the whole or part of this work in unaltered form for your own personal use or, if you are part of an organisation, for internal use within your organisation, but only if you or your organisation do not use the reproduction for any commercial purpose and retain this copyright notice and all disclaimer notices as part of that reproduction. Apart from rights to use as permitted by the Copyright Act 1968 or allowed by this copyright notice, all other rights are reserved and you are not allowed to reproduce the whole or any part of this work in any way (electronic or otherwise) without first being given specific written permission from the Commonwealth to do so. Requests and inquiries concerning reproduction and rights are to be sent to the TGA Copyright Officer, Therapeutic Goods Administration, PO Box 100, Woden ACT 2606 or emailed to tga.copyright@tga.gov.au.

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For correspondence or further information about Medicines Safety Update, contact the TGA's Pharmacovigilance and Special Access Branch at ADR.Reports@tga.gov.au.

Medicines Safety Update is written by staff from the Pharmacovigilance and Special Access Branch.

Acting Editor: Dr Catherine Brogan

Deputy Editor: Mr Michael Pittman

Contributor: Mr David Phuong