So, another response from the British medicines regulator, the MHRA, regarding the benefit vs risk ratio of the antidepressant, Prozac.
It's been painstaking trying to get to the logic behind some of their responses, in fact, it's been suggested that some of their responses to me regarding this issue have been 'obtuse'. It is, however, important that I try to keep this line of communication open with them, if only, to have their responses made public via this blog.
Regular readers will recall that I have been scratching my head regarding the MHRA's stance that one apparent benefit of taking Prozac outweighs the number of adverse events reported by Prozac users or their treating physicians - a list of which can be seen, ironically via the MHRA's own web page, here.
As suspected, the MHRA are now telling me that the list of adverse events reported for Prozac should not be "interpreted as a list of possible side effects to a medicine," furthermore, they add, "It is important to note that causality has not been proven in these reports."
Here is their full response to me - it may help if you read the previous correspondence between myself and the MHRA regarding Prozac's benefit vs risk in order - 1, 2, 3.
So, here's their latest - my response to this follows...
Dear Mr Fiddaman
Many thanks for your email of 25 November 2016.
Most medicinal products that contain one active substance exert their effect through one mechanism of action, in this case through raising the level of serotonin in the brain (which can improve symptoms of depression). In addition, most medicinal products have a range of possible side effects. It should be noted that the frequency of such side effects are considered when evaluating the benefit/risk profile of a product to determine whether it should be granted a marketing authorisation. The frequency of these side effects are also monitored after a marketing authorisation is granted to ensure that the benefit/risk profile of a product is still positive.
The Drug Analysis Print (DAP) for fluoxetine represents a listing of all suspected adverse drug reactions or side effects that have been reported to the MHRA via the Yellow Card Scheme. This includes all reports received from healthcare professionals, members of the public, and pharmaceutical companies. It is important to note that causality has not been proven in these reports; reporters are asked to submit a Yellow Card report even if they only have a suspicion that the medicine may have caused the adverse drug reaction. For this reason it is very important that the information within a DAP is not interpreted as a list of possible side effects to a medicine. The data shown in our DAPs can be very useful in helping to identify possible medicine safety issues. However, this information does not present a complete overview of the potential side effects associated with specific medicines. Conclusions on the safety and risks of medicines cannot be made on the data shown in the DAP alone. Patients should instead refer to the Patient Information Leaflet for the most complete and up to date information on possible side effects.
Best regards
The FOI Licensing Team
--
My response...
Please find my following up questions in bold font below.
(MHRA's statements are in italics.)
Most medicinal products that contain one active substance exert their effect through one mechanism of action, in this case through raising the level of serotonin in the brain (which can improve symptoms of depression).
1. Is this a definitive answer, ie; Are you saying that you (the MHRA) have clinical and scientific evidence that, in this instance, Prozac improves depression by raising the level of serotonin in the brain? If so, could you please forward me the scientific literature that clearly shows this to be true. If this is just a 'common belief' could you please state, for the record, that the evidence of Prozac improving depression by raising the level of serotonin in the brain is inconclusive.
In addition, most medicinal products have a range of possible side effects. It should be noted that the frequency of such side effects are considered when evaluating the benefit/risk profile of a product to determine whether it should be granted a marketing authorisation.
2. Is this based on the clinical trials that last between 8 and 12 weeks?
The frequency of these side effects are also monitored after a marketing authorisation is granted to ensure that the benefit/risk profile of a product is still positive.
3. Monitored by whom? Can you please explain the system of monitoring - ie; does monitoring include reading 'anecdotal reports of adverse events ' on Prozac forums?
The Drug Analysis Print (DAP) for fluoxetine represents a listing of all suspected adverse drug reactions or side effects that have been reported to the MHRA via the Yellow Card Scheme. This includes all reports received from healthcare professionals, members of the public, and pharmaceutical companies. It is important to note that causality has not been proven in these reports.
4. Out of all the adverse events reported for Prozac via the Yellow Card System, how many have been found to show that Prozac was the causality and how many have been shown that Prozac was not the causality?
...reporters are asked to submit a Yellow Card report even if they only have a suspicion that the medicine may have caused the adverse drug reaction. For this reason it is very important that the information within a DAP is not interpreted as a list of possible side effects to a medicine.
5. How do you, the MHRA determine whether or not the adverse events reported via the Yellow Card System are caused by Prozac?
The data shown in our DAPs can be very useful in helping to identify possible medicine safety issues. However, this information does not present a complete overview of the potential side effects associated with specific medicines.
6. Thus far, you, the MHRA have given me just one benefit of Prozac, namely that it "can" improve symptoms of depression by raising the level of the neurotransmitter, serotonin, in the brain. When you suggest that it "can" are you saying that sometimes it can't? Please clarify what you, the MHRA, mean when you claim that it "can" improve symptoms of depression.
Conclusions on the safety and risks of medicines cannot be made on the data shown in the DAP alone. Patients should instead refer to the Patient Information Leaflet for the most complete and up to date information on possible side effects.
7. If a doctor, or patient, for that matter, files an adverse event via the Yellow Card System do you, the MHRA write back to them if you determine that Prozac was the causation? Do you, the MHRA, at any point, visit the reporter to try and gain more information - if so, in the past 12 months, how many times has the MHRA visited a reporter of an adverse event regarding Prozac?
Sincerely,
Bob Fiddaman
No comments: