TGA calls for extreme caution after off-label prescription death
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.
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.