Australia’s drug regulator has issued a safety warning over the medicine Phenergan and related products containing the antihistamine drug promethazine.
The Therapeutic Goods Administration said the over-the-counter products should not be given to children under six due to concerns of serious side effects including hyperactivity, aggression and hallucination. Breathing can also become slow or shallow, which can be fatal.
When high doses are given, young children may also experience difficulties in learning and understanding, including reversible cognitive deficit and intellectual disability, the TGA said.
The latest alert follows international and Australian concerns about the medicine in young children, which is commonly used to manage conditions such as hay fever and allergies, travel sickness and for short-term sedation.
What is promethazine?
Promethazine is a “first generation” antihistamine that has been sold over the counter at pharmacies in Australia for decades for a range of conditions.
Unlike many other drugs, first generation antihistamines can cross the blood-brain barrier. This means they affect brain chemistry, resulting in people feeling drowsy and sedated.
In adults this may be useful to bring on sleep. But in children, these drugs can have serious side effects on the nervous system, including those listed in this week’s safety alert.
We’ve known about this for a while
We’ve known about the serious side effects of promethazine in young children for some time.
Advice about 20 years ago in the United States was not to use the drug in children under two years of age. In 2022, the Australian Advisory Committee on Medicines issued its own recommendation to increase the age to six. New Zealand issued a similar warning and advice in May this year.
Over the past ten years, 235 cases of severe side effects to promethazine in both children and adults have been reported to the TGA. From the 77 reported deaths, one was a child under six.
The reported side effects for both adults and children included:
- 13 cases of accidental overdose (which resulted in 11 deaths)
- eight cases of hallucination
- seven cases of slow or shallow breathing (which resulted in four deaths)
- six cases of lowered consciousness (which resulted in five deaths).
The TGA’s safety alert comes after an internal investigation by the manufacturer of Phenergan, Sanofi-Aventis Healthcare. This investigation was prompted by the 2022 advice from the Advisory Committee on Medicines. The company has now updated its information for consumers and health professionals.
What can you use instead?
For allergies or hay fever in young children, non-sedating antihistamines such as Claratyne (loratadine) or Zyrtec (cetirizine) are preferred. They offer relief without the risks of sedation and the other worrying side effects of promethazine.
For cold or cough symptoms, parents should be reassured these typically get better with time, fluids and rest.
Saline nasal sprays, adequate hydration, a humidifier, or elevating the child’s head can alleviate congestion associated with hay fever. Oral phenylephrine products, marketed for nasal congestion, should be avoided, as evidence shows they are ineffective, but nasal spray formulations of the drug are fine to use.
For fever or discomfort, paracetamol remains a safer choice.
What else can I do?
If you have a bottle of Phenergan or a related product, avoid tipping the medicine down the sink or throwing the bottle in the bin, as this can harm the environment. Instead, return it to the pharmacy for safe and responsible disposal.
A pharmacist can also advise on choosing the most appropriate treatments for your child, and knowing when to seek medical attention.
If your child has concerning side effects from taking promethazine, or any other medicine, call the Poisons Information Centre immediately on 13 11 26. In an emergency in Australia, call 000.
Nial Wheate in the past has received funding from the ACT Cancer Council, Tenovus Scotland, Medical Research Scotland, Scottish Crucible, and the Scottish Universities Life Sciences Alliance. He is a fellow of the Royal Australian Chemical Institute, a member of the Australasian Pharmaceutical Science Association and a member of the Australian Institute of Company Directors. Nial is the chief scientific officer of Vaihea Skincare LLC, a director of SetDose Pty Ltd (a medical device company) and was previously a Standards Australia panel member for sunscreen agents. Nial regularly consults to industry on issues to do with medicine risk assessments, manufacturing, design, and testing.
Associate Professor Tina Hinton has previously received funding from the Schizophrenia Research Institute (formerly Neuroscience Institute of Schizophrenia and Allied Disorders). She is currently a Board member of the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists.
Jasmine Lee does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
This article was originally published on The Conversation. Read the original article.
