Minocycline and agranulocytosis
Health professionals are advised that the Product Information (PI) for minocycline is in the process of being updated to include information about agranulocytosis, a rare but potentially life-threatening adverse event.
Minocycline is a tetracycline antibiotic that may be used to treat acne that is resistant to other antibiotics, as well as various other susceptible infections.
It is marketed in Australia under the tradename Minomycin and the generic brand Akamin.
Cases of agranulocytosis have been reported to the Therapeutic Goods Administration (TGA) following treatment with minocycline. As at 25 August 2021, the TGA had recorded reports of 4 cases for minocycline involving agranulocytosis. One case had a positive de-challenge while another was a fatal case reported as tetracycline-induced agranulocytosis. In the other 2 cases, minocycline-induced agranulocytosis could not be ruled out, as the cases were confounded by other medicines known to cause agranulocytosis.
Agranulocytosis is a serious condition that occurs when there is an extremely low number of granulocytes (a type of white blood cell) in the blood. Signs and symptoms of agranulocytosis include fever, chills, weakness, sore throat, sores in the mouth or throat, bleeding gums, bone pain, low blood pressure, fast heartbeat, and trouble breathing. People with this condition are at very high risk of serious infections due to their suppressed immune system.
Agranulocytosis is a rare but serious condition with a reported incidence ranging from 1 to 5 cases per million population per year. An association with medication use can be found in about 70% of cases.
Information for prescribers
Prescribers should be aware of the potential risk of agranulocytosis associated with minocycline and the importance of early recognition and monitoring of full blood count and liver function tests during treatment.
Prior to treatment with minocycline, patients should be made aware of the risk, including signs and symptoms, and what to do in the event of suspected agranulocytosis.
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:
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.
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Medicines Safety Update is written by staff from the Pharmacovigilance and Special Access Branch.
Editor: Dr Catherine Brogan
Deputy Editor: Mr Michael Pittman
Contributor: Mr David Phuong and Ms Renae Mura