There have been several reports to RxISK of young men committing suicide on doxycycline. This led us to investigate further. The evidence seems clear – doxycycline can cause someone to commit suicide. We have no idea how often this happens but that it happens is certain.
The first report came from a mother in Australia who reported the death of her teenage son, who had been put on doxycycline for a minor dermatitis affecting his face. RxISK.org takes people through a causality algorithm to establish whether there is a link between their treatment and the adverse event. This algorithm expands on standard causality algorithms in the field such as the Naranjo algorithm. It gives a RxISK score. In this case the algorithm generated a score of 6 which points to a likely link between the treatment and the adverse event.
One of the goals behind RxISK is to get the person involved or a concerned family member to take a RxISK report to a doctor, pharmacist or someone else to get a conversation going and to intervene early. In this case, it is too late to prevent an injury but there are important conversations that families still need to have with their doctor or others. If there is agreement between doctor and the family member or the healthcare team that the drug has caused a problem in this case, this is the best evidence there is that the drug likely did cause the problem.
In this case the doctor had been consulted before the RxISK report had been written. The doctor had already written to the Australian drugs regulator, the Therapeutic Goods Administration (TGA). Although her letter did not blame the drug, it offered no other explanation for this death other than the effect of the drug. Her question was ‘did the TGA have any evidence doxycycline could cause suicide?’
In fact the true RxISK score in this case should probably have been a great deal higher than the 6 reported here that pointed to a likely link. It should have been 9 or greater, which points strongly to a link. The reason it should have been higher is that several years beforehand, this young man’s elder brother had also been prescribed doxycycline as an anti-malarial pill. He stopped the drug after experiencing a lot of anxiety, insomnia and feeling ‘not right’.
The family did not make the connection between an anti-malarial drug one son had and the treatment for dermatitis another was put on some years later. If we take this earlier reaction into account, we have evidence for a challenge, de-challenge and re-challenge which would make for compelling evidence for a link between the treatment and the adverse event.
Challenge, de-challenge and re-challenge offers the kind of conclusive evidence for causality that many of us once applied to Christmas tree lightbulbs. Attempts to start the Christmas tree lights after they have been put away for a year often failed. Until the recent replacement of bulbs by LEDs, the next step was to unscrew each bulb in turn and if the lights came on when a particular bulb was unscrewed and went off again when that bulb was screwed back in this was taken as conclusive evidence that this bulb was the cause of the problem.
Challenge, de-challenge and re-challenge operates the same way and it appears very clear in the case of this family.
In response to the letter from the family doctor, Dr Hammett of the TGA noted that there had been no reports of completed suicides in Australia, other than this young man’s case. He conceded that there had been 15 or so reports of anxiety reactions. He also noted that there was nothing in the academic literature worldwide suggesting that this drug causes suicide.
This is a standard regulatory response to any questions like this from a doctor, or journalist, or family member. The first point is that regulators will never say a drug has caused a problem. They are still prepared to say that in the case of a limbless baby that the thalidomide its mother was on might have prevented a miscarriage rather than caused limblessness. When a young person hangs themselves on an SSRI, it is commonly because they are troubled by thoughts of self-harm and test their feelings out by putting their head in a noose which unfortunately can press on the carotid bodies on either side of their neck, cause them to slip out of consciousness and hang themselves in a manner that leaves them almost kneeling. In these cases regulators might raise the possibility that this is auto-erotic asphyxiation gone wrong.
The second thing a regulator will do is contain their search within national boundaries. Had the regulators in this case broadened the search out beyond Australia they would have found compelling evidence from the FDA database on RxISK.org. FDA have 16 reports of completed suicides on doxycycline since 2004, 18 reports of suicidal ideation and 17 reports of suicide attempts. Of the 16 suicides, 3 come from Australia.
Had the TGA gone further they might have found a petition on Change.org Doxycycline Causes Suicide in Teens that was put in place by Tara McCarthy after the death of her son Damien. Over 3,800 people have signed up to this requesting that the drug be more appropriately labelled.
On another information site making FDA data on adverse events available, eHealthMe.com, under the heading of suicide attempt there are 111 reports of suicide attempts from the FDA database. The difference in the number of reports between here and RxISK stems primarily from the fact that eHealthMe somewhat confusingly also includes data on doxycycline where doxycycline is not the only drug in the mix. In the case of someone given doxycycline for acne, and also given Roaccutane which is well known to cause suicide, eHealthMe files the event under doxycycline making it difficult to get a clear picture.
But aside from the figures, there is more compelling evidence that turns up on Google. Here are two narrative reports that appear uncomplicated by secondary drug intake.
A Mr Davies reported:
“I am a 42 year old male father of two. I started taking Doryx pills for a ruptured cyst several months ago and it did reduce the size and swelling. I have never thought about suicide before but within a few weeks of starting this medicine I have had the idea just pop into my head. I am not sure why – I am healthy and well-off and have a great relationship with my children and friends. I stopped taking the medicine for several months and have not had any ‘thoughts’ since.
Recently I began taking it again after checking the side effects and not finding depression or suicidal tendencies among them. After a couple of days back on it I again started having these thoughts. This prompted me to query Doryx plus suicide on Google and I found this page and a few others that mention others having similar experiences”.
RxISK aims at being the natural home for narratives like this and putting a megaphone in the hands of people who have experiences like this by giving them data on other cases but also engaging them with their doctor, pharmacist or local healthcare community.
A woman called Carrie also reports that:
“My 14 year old daughter just attempted suicide after several months on doxycycline for acne. She now says she has had suicidal ideation since shortly after starting the medication several months ago. Her dose of doxycycline was doubled a few weeks before her suicide attempt. She herself says she was not sad, she had no other signs of depression and does not understand why she felt compelled to kill herself. She gets good grades, is involved with clubs and friends and demonstrates appropriate affection. The timing with doxycycline is just too coincidental to not be connected.”
My personal interest in the issue of doxycycline and suicide was stimulated in the first instance by a colleague who reported very similar reactions. He took doxycycline for malaria prophylaxis when visiting South America some years ago. He noticed that he became anxious and irritable and had a change in personality. He did not connect this change to the drug at the time. He began to suspect the drug when he returned to the UK and stopped taking it.
A year later he visited China and again took doxycycline for malaria prophylaxis. When the same reaction happened a second time he was very clear that the doxycycline was causing the problem. Again the problem cleared up once he was in a position to stop the treatment.
Another report was filed with RxISK on yet another young man, who in this instance was put on doxycycline for mild acne. He took a first course in a low dose for over a year. He later reported to his parents that he had not liked its effects and felt better off it. This looks far more clear retrospectively than it looked at the time to his family. Six months later he went back on doxycycline but this time round was accidentally placed on double the dose and some weeks later committed suicide. His mother compiled a RxISK report but ended up with a much lower score than she should have for two reasons. One was because she was unaware of comparable reactions elsewhere.
The second was she filed the report to indicate her son had not increased the dose when in fact he had. She was right that the package was still labelled doxycycline 50 mg but in fact the pharmacist has accidentally dispensed 100 mg tablets. The aggravation of a problem with an increase in dose is almost as conclusive as the Christmas tree light bulb effect.
There is a compelling case that doxycycline can cause people to commit suicide.
At RxISK we are interested in any ideas anyone has as to the mechanism through which it causes suicides. In addition to any other problems doxycylcine may cause, we welcome other reports of suicidal or violent reactions or other strange behaviors linked to it. We are particularly interested in what your experience is like from the inside if anything like this has happened to you.
We are equally interested in any comments about why doxycycline cannot cause suicide and how someone might be mistaken into thinking that it could.
This story makes clear why report to RxISK.
Reporting to companies alone is pointless. They will bin, distort or degrade even compelling reports to the status of anecdotes.
Reporting to regulators alone, or companies and regulators alone, is also pointless. Regulators will never attempt to establish whether the drug did cause a problem in your case. There is nothing any regulator will ever do to help explain anything to a family or an affected individual. Their job is to regulate the wording of advertisements not to look after the public health in general or get involved in your case in particular.
(We would welcome any reports from anyone who has had anything useful back from a regulator).
The ideal is to report to RxISK and use a RxISK report to engage your doctor in the issue. If both you and your doctor think the drug has caused the problem, regardless of what companies or regulators might say, there is a chance of a successful intervention in a developing problem or getting closure after an injury has happened but there is also the possibility of mobilizing people to make treatment safer. Your doctor can give you more support than anyone. But equally, do not underestimate how much you can do for your doctor – your case may take her back to kind of ideals that brought her into medicine in the first place.