|Department of Health|
|MEDICINES CONTROL AGENCY|
|Market Towers 1 Nine Elms Lane London SW8 5NQ|
|TEL: 020 7273 0400|
|FAX: 020 7273 0675||.Ref: OG 02/47|
|07 January 2003|
Dear Mr Medawar,
Electric head symptoms on withdrawal of paroxetine
Thank you for your letter of 11 December on the subject of the electric head symptoms experienced by some patients on withdrawal of paroxetine. I will answer your questions in turn:
1. How is the phenomenon presently coded in the ADROIT system?
We have a term Electric shock sensation on the ADROIT medical dictionary.
2. Please would you supply us with a copy of any document (or extracts thereof) giving advice on coding or classification to those responsible for entering Yellow Card, data specifically relating to SSRI etc withdrawal reactions, on to the ADROIT database?
I attach a copy of the Standard Operating Procedure relating to classification of withdrawal reactions on the ADROIT database. Please note that is not to be disclosed.
3. In the MCA/CSM statement on SSRIs in Current Problems in Pharmacovigilance (September 2000, 12), it is stated: "there have been isolated reports of more serious symptoms on withdrawal such as severe electric shock sensations..." Please could you explain the basis on which this assessment of magnitude ("isolated") was made, indicating also the numbers of reports received that were considered "severe" or not?
Isolated is a descriptive term and is not associated with a particular frequency. The sentence was added to the article in Current Problems in Pharmacovigilance because of the existence of well-documented literature reports of severe electric shock sensations and other serious reactions on withdrawal of SSRIs. At the time of this article there were 40 spontaneous reports on the ADROIT database which listed the term electric shock sensation in association with drug withdrawal reactions.
4. There is no reference to electric shock sensations in either the Seroxat SPC (which warns of "dizziness, sensory disturbance ...and confusion following abrupt withdrawal"); nor in the Patient Information Leaflet (which refers to "tingling sensations."). Please could you explain why not, and whether the MCA/CSM has ever proposed to companies holding licenses for SSRI and related antidepressants that this characteristic of withdrawal should be referred to in product warnings?
We agree that the wording in the SPC and PIL should be more specific than the present term sensory disturbances and the addition of more specific terms in relation to electric shock sensations is currently under review.
5. Please could you say whether the MCA/CSM have made or will now undertake some assessment of the neurological implications and clinical significance of this electric head phenomenon? If any assessment has been done, please would you indicate what enquiries were made (e.g. to companies holding licenses for SSRI and related antidepressants) and what if any conclusions have been drawn?
We do not have evidence of long term neurological or clinical implications of the electric shock sensations that are experienced on withdrawal of SSRIs. The present expert Working Group on SSRIs includes neurological expertise and as stated above, the wording in the SPC and PIL is currently under review.
Yours sincerely DR J M RAINE, Director, Post-Licensing Division
CLICK HERE TO READ ON