Ingenol mebutate - hypersensitivity reactions, herpes zoster and eye injury

Ingenol mebutate, marketed in Australia as Picato gel, is indicated in actinic keratosis. Its mechanism of action is to induce local lesion cell death and to promote an inflammatory response by production of proinflammatory cytokines and chemokines to infiltrate the immunocompetent cells. This mechanism in itself causes application site pain, pruritus, irritation, infection and oedema.

 

The TGA investigated safety concerns relating to ingenol mebutate following reports of severe allergic reactions, herpes zoster, ophthalmic injury and local skin reactions in the United States. Some of the cases were associated with the medicine not being used in accordance with its directions for use.

 

The TGA investigation found that the risk of local skin reactions was well-communicated in the Product Information(link is external) (PI). However, the PI did not address the potential adverse events of hypersensitivity/anaphylaxis, herpes zoster reactivation or ophthalmic injury.

 

Based on this, the TGA worked with the sponsor to update the Precautions and Adverse Effects sections of the PI for ingenol mebutate with appropriate information.

 

The Consumer Medicine Information(link is external) (CMI) for ingenol mebutate instructs patients to 'follow carefully all directions given to you by your doctor or pharmacist'. With this in mind, provide your patients clear instructions regarding application of this medicine and consider providing them a copy of the CMI.

Reference

TGA Medicines Safety Update, Volume 8, Number 2, April-May 2017