Electronic Letters to:
|
|
eLetters: Electronic letters published:
-
![[Read eLetter]](/icons/misc/sectionDOWN.gif)
Flumazenil is contraindicated in mixed tricyclic and benzodiazepine overdose
- Richard M Lynch, Richard M Lynch (8 January 2002)
-
Tricyclic antidepressant overdose
- Cathy Kelly, Catherine Kelly (8 January 2002)
|
|
|||
|
Richard M Lynch, Specialist Registrar A&E A&E Department, Hull Royal Infirmary, UK, Richard M Lynch
Send letter to journal:
rlynch{at}tinyworld.co.uk Richard M Lynch, et al.
|
Dear Editor I read with interest Kerr et al’s highly informative article, Tricyclic antidepressant overdose: a review.[1] However, I would like to highlight an important point which the authors have not mentioned. In cases of mixed overdose, of tricyclic antidepressants and benzodiazepines, flumazenil (Anexate) is contraindicated. It has produced convulsions and ventricular arrhythmias in the presence of tricyclics.[2] The mechanism for this interaction is thought to be unmasking of tricyclic antidepressant-induced seizures as a consequence of flumazenil antagonising the anti-epileptic effect of concomitantly ingested benzodiazepines.[3] This interaction has resulted in a number of deaths.[2,3] In patients presenting following overdose, it is not always easy to obtain a clear and accurate history regarding what substances have been ingested. The administration of flumazenil as a diagnostic aid in these patients is potentially dangerous and should be avoided, particularly if Tricyclic antidepressants have been taken. References |
|||
|
|
|||
|
Cathy Kelly, Consultant Physician Scottish Poisons Information Bureau, Catherine Kelly
Send letter to journal:
cathy.kelly{at}luht.scot.nhs.uk Cathy Kelly, et al.
|
Dear Editor, Kerr et al[1] point out in their review that despite the introduction of newer antidepressant agents in recent years, a large number of prescriptions for tricyclic antidepressants are still issued. Data from our unit suggests that overdose with selective serotonin re-uptake inhibitors (SSRIs) has now become more common than with tricyclic antidepressants. Despite this, there were 4981 accesses to information on dothiepin or amitriptyline on TOXBASE last year, suggesting that tricyclic poisoning remains a substantial problem. [2] The authors also suggest that advice given from National Poisons Information Service (NPIS) centres may differ. TOXBASE, the clinical toxicology database of the UK NPIS, provides information on drug toxicity and advice on clinical management after overdose. It is the recommended first point of access to poisons information by all centres of the NPIS and has been available on the internet since August 1999.[3] All new drug entries, and revisions of existing entries, are circulated to the directors of all the NPIS centres for comments before going live on the system. In many cases there is a paucity of evidence on which to base treatment and in these cases the advice given is based on consensus of the NPIS centre directors. Evidence-based treatment is clearly referenced in recent entries. In complicated or difficult cases, advice beyond that given on TOXBASE may be required and discussion with an NPIS centre is encouraged. We hope the more widespread use of TOXBASE on the internet will standardise the advice given. We also anticipate that the introduction of a single telephone number for enquiries, 0870 6006266, which will route the caller to the nearest NPIS centre will reduce any confusion, which in the past has been caused by clinicians ringing different centres about the same case. The inevitable differences in emphasis given by callers will affect advice received. We continue to encourage calls about unusual or complex cases, particularly multiple ingestions of potentially toxic amounts. If there appears to be inconsistent advice from TOXBASE and an NPIS centre, we encourage discussion with us (spib{at}luht.scot.nhs.uk) so that the matter can be brought to the attention of the NPIS directors. References |
|||
