TGA calls for extreme caution after off-label prescription death

Perth man ingests toxic quantity of medication by mistake

The TGA is advising "extreme caution" when dispensing off-label atropine eye drops to treat hypersalivation, following the death of a Perth man who ingested a toxic quantity of the medication.

Caution safety first

The man died in 2014 after ingesting 6-8mL of atropine, which is more than 50-100 times the expected therapeutic dose.

A coronial investigation found the atropine had been prescribed off-label for sublingual administration to treat hypersalivation.

Hypersalivation is not an approved indication for atropine eye drops in Australia.

The coroner found no evidence to suggest the patient — who had been diagnosed with bipolar affective disorder — was suicidal, and therefore ruled the ingestion of a toxic quantity of atropine was accidental.

While “shortcomings” were found in the patient’s care, the coroner said they were not the result of incompetence or a lack of goodwill.

The coroner did note, however, the root cause was a “lack of awareness” that atropine was potentially lethal and also recommended atropine drops not be stored in soft, squeezable bottles.

The TGA has flagged the issue in a medicines safety bulletin posted online.

It says a toxicology evaluation shows that higher systemic exposure to atropine eye drops is expected from sublingual administration compared with taking tablets due to bypassing of first-pass metabolism.

“As a result, toxicity is expected to be seen at lower sublingual doses than oral ones,” the TGA says.

“Extreme caution is recommended if you are considering off-label prescribing of atropine eye drops for hypersalivation.

“You 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, and patients should be closely monitored during treatment.”

More information: Read the TGA's Medicines Safety Update.