Safety Information

Published: 20 December 2019

Monitoring

Update on suspected adverse reaction reports to lamotrigine after changing brands

 

Background
Products affected
Adverse reaction reports
Information for prescribers
Reporting
References

Update

This communication has been updated to describe new information on the experiences of patients changing brands of lamotrigine and to update the information on the number of deaths reported to the Centre for Adverse Reactions Monitoring (CARM). We do not intend updating this communication further unless the reported patient experiences change significantly.

Background

The funding of lamotrigine 25 mg, 50 mg and 100 mg dispersible tablets changed on 1 October 2019 following a five-month transition period beginning 1 May 2019. This communication provides an updated summary of suspected adverse reactions reported to the Centre for Adverse Reactions Monitoring (CARM) since the transition period started. Medsafe continues to monitor these reports closely.

Products affected

The funded brand of lamotrigine 25 mg, 50 mg and 100 mg dispersible tablets is now Logem.  There were three products funded previously (Arrow-Lamotrigine, Lamictal, Logem).

There are no changes to the funding of lamotrigine 2 mg and 5 mg dispersible tablets.

Lamotrigine is used for the treatment of epilepsy in adults and children from two years of age, and for the treatment of mood episodes in adults with bipolar disorder.

Adverse reaction reports

CARM has received reports from both healthcare professionals and patients. Reports received about patients who have had a change in brand include the following:

• Changes in seizure control in patients taking lamotrigine for epilepsy.  This includes patients who were previously seizure-free and experienced seizures after changing brands, and an increase in seizure frequency in those who were not seizure-free. In addition CARM have received reports of patients experiencing aura-like symptoms that they normally experience before a seizure.
• Changes in mood symptoms in patients taking lamotrigine for bipolar disorder. This includes reports of suicidal ideation or suicide attempt.
• Other reported reactions include headache, hot flushes, memory loss, rash and tiredness.

Sadly, CARM has now received five cases reporting death as an outcome. All five cases are under Coronial investigation because the cause of death in each case is unknown. All reports of death considered by CARM to be related to use of a medicine are discussed by the Medicines Adverse Reactions Committee (MARC) at the subsequent meeting. In addition, the MARC review all reports of death annually to check for any trends that may need addressing.

Unfortunately, each year there are a number of people with epilepsy who die and no other cause of death can be found. This is called sudden unexplained death in epilepsy (SUDEP). Each year, SUDEP affects about 1 in 1,000 adults with epilepsy and 1 in 4,500 children with epilepsy1.

Please note adverse reactions are reported to CARM based on a suspicion that the medicine could have caused the reaction. A causal link between brand changes of lamotrigine and the adverse reactions described here has not been established.

Information for prescribers

Medsafe recommends prescribers follow the UK Medicines and Healthcare products Regulatory Agency’s (MHRA) advice that lamotrigine brand changes must be managed carefully with close patient monitoring, taking into account factors such as seizure frequency and treatment history2. The evidence that lamotrigine has a narrow therapeutic window is inconclusive at present. However, there is information to show that patients find changing brands difficult3.   

PHARMAC has widened acess to their exceptional circumstances process for patients who are taking lamortigine. PHARMAC has also stated they will reimburse some GP visit. More information is available on PHARMAC’s website.

Information for consumers

If you are concerned about changing brands of lamotrigine please talk to your doctor who can make an exceptional circumstances application.

If you have already switched brands and are stable, do not change brand again.

If you have switched and are having problems please see your doctor as soon as possible. PHARMAC have stated that they will reimburse some GP visit co-payments.

Reporting

Please report any suspected adverse reactions to lamotrigine to CARM.

Reports are confidential – any information that is shared with government departments to improve the safety of medicines in New Zealand is anonymised

References

1. Health Navigator. 2017. Epilepsy. URL: www.healthnavigator.org.nz/health-a-z/e/epilepsy/ (accessed 6 November 2019).
2. Medicines and Healthcare products Regulatory Agency. 2017. Antiepileptic drugs: updated advice on switching between different manufacturers’ products. Drug Safety Update 11(4): 5. URL: www.gov.uk/drug-safety-update/antiepileptic-drugs-updated-advice-on-switching-between-different-manufacturers-products (accessed 22 October 2019).
3. Epilepsy Society and Epilepsy Action. 2014. Patient experiences of switching between different versions of anti-epileptic drugs. URL: www.epilepsyresearch.org.uk/wp-content/uploads/2015/02/Patient-experiences-of-switching-between-different-versions-of-AEDs.pdf (accessed 8 November 2019).