Metronidazole and the subjective nature of reality

Written Friday, 1st September, 2006

The last 5 days have been some of the worst days of my life.

It all started with that incompetent dentist I've been whining about. As I've already mentioned, I had have an emergency root canal on Sunday morning to relieve the pain from an abscess under one of my teeth. With the treatment, I gratefully accepted a 3-day course of antibiotics to cure the infection that caused the abscess.

Grumpy, in pain, and exhausted from the lack of sleep, I did nothing at all on Sunday. I felt particularly annoyed because it was supposed to be the first day of my vacation proper, and I had planned to spend the days off happily coding away on one or another of various personal projects. But now I felt in no fit state to do so.

Over the next couple days, my mood did not improve. I stayed indoors, off instant messenger, doing nothing and talking to no-one except my flatmate when he came in. I declined offers of friends and family. None of this was really unusual; I occasionally do this kind of thing.

But I felt unwell. Obviously I was physically unwell with the pain in my teeth, but I also felt generally unwell and, well, grumpy. Upset. I chided myself for overreacting to a little pain and inconvenience and expense. "I've got nothing really to complain about, and it's all my own fault anyway," I though to myself, "don't go whining to everybody about how your teeth are making you depressed, they'll just joke about it and tell you to get a sense of perspective. Just avoid people until you get better."

So that's what I did. Except I *didn't* get better. My tooth got slowly better, but too slowly. It was now Tuesday and I was still in pain. Reading the directions that came with the antibiotics, they specified a 3-day course for "dental infection" and a 7-day course for "acute dental infection". Well, if this wasn't acute, I didn't know what was. I'd had an abscess and been on antibiotics for them before, and that course had been 5 days. So as I had the pills anyway, I decided to lengthen the dose, as I know that an insufficient dose of antibiotics is worse than none.

And my mood got worse. I lay around watching old science fiction tv and reading comic books -- my comfort actions, as any friend of mine will tell you. I achieved none of my personal projects, I just sat there, dwelling on the pain and expense of my teeth, and feeling overwhelmed at the futility of doing anything. I couldn't face seeing anybody or doing anything. The thought of returning to work made me cringe. I just wanted to hide in a dark hole somewhere forever, and have nobody bother me.

All of this was a total overreaction, obviously, to what had actually happened. In retrospect, I recognize those sorts of feelings. The last time I had them was when I was 16, when I used to cry myself to sleep to the sound of radiohead, unhappy with my sexuality. Back then I did any number of stupid online tests all of which said I was clinically depressed. Every little thing seemed like the straw to break the camel's back. Every little setback loomed huge. It happens to every teenager, and like every teenager, I grew out of it. I should have questioned why I was feeling this way now, but it didn't occur to me.

Back from work one of those evenings, my flatmate idly mentioned that a colleague of his had been late for work because someone had thrown themselves under a train at Clapham Junction. We joked at the general "tut-tut" response this elicts from most Londoners, annoyed at the delay to their journeys. But it set me off: for the first time since I was sixteen, I thought about suicide.

I thought a lot about suicide when I was fifteen and sixteen. I had planned to commit suicide on my 16th birthday. The property where we lived featured a very high cliff-like retaining wall ending in concrete, and my school had a fourth-floor classroom with (in one of those features only a third-world school could get away with) an entirely open balcony with a low wall, also conveniently over a concrete basketball court. No shortage of methods presented themselves; it would be easy. I even dropped hints of the plan to friends. There was no point to my life, I thought at the time. All nature designed me to do is reproduce, and I wasn't going to do that, so why bother?

On the actual day of my birthday, in typical teenage fashion, I was too distracted by birthday presents to even remember that I'd planned to do something. Subsequently, I came up with a pretty neat justification for my lack of action.

First, note that a big reason for my depression was that my discovery of my sexuality had radically altered my perception of my place in the world. I suddenly went from being the golden child to (in my mind; I'd not told anyone yet) the family outcast, and from being a fine upstanding member of society to a pervert (internalized homophobia; isn't it wonderful?).

So what I told myself was: okay, I did commit suicide. I'm dead now. Therefore, the yardstick to measure anything that happens after this time is not relative to the theoretical rich whiteboy I'd thought I was, but to zero. Relative to no life at all, any sort of life at all wasn't just acceptable, it was great. So it didn't matter how bad things got: they were still better than they'd been on my 16th birthday, when I died.

The same dark thoughts were still buzzing around in my head on Friday morning as I packed to go on vacation with the family, to Bilbao. Everything was incredibly frustrating to me now. I'd got the flight date wrong -- I was coming back Sunday, not Monday. I couldn't find my clothes. My tooth still hurt. I didn't have a bag the right size. I was broke from paying for the dentist. All these petty little things that ordinarily I would brush aside without a second thought seemed huge, unbearable. I considered cancelling, backing out of the vacation entirely. The only thing that stopped me was I couldn't think of a good reason to do so -- my tooth? Feeling anti-social? Pretty silly reasons to waste a couple hundred quid on cancelled flights and reservations. It would just be ridiculous.

As I walked down Clapham High Road to the tube, for the first time I thought: why am I so unhappy? Is it really just the dentistry? The money? Frustration at not having achieved anything in my week off? Was I not over my ex, who I'd unexpectedly bumped into a few weeks before? But that had seemed to go so well at the time, and was in any case weeks ago. What was making me unhappy now? I couldn't think of anything. It just seemed, even to me, that I was totally overreacting to minor setbacks. I continued to toy with backing out -- it was only a short trip, after all. I crossed the little triangular park outside Stockwell station and waited at the lights to cross.

The junction outside Stockwell tube always has heavy traffic, and is a major bus route, so the lights are quite a wait if you miss them. The first stream of traffic passed from the east, and I watched idly, thinking only how unable to face a vacation I felt. The ridiculousness of being "unable to face" a vacation didn't occur to me.

The lights changed, and there was that five second lull you get as the north-bound traffic accelerated away from the lights. I could see a double-decker in the queue. And the thought crossed my mind: by the time it passes here, it'll be going fast enough. It only take six steps to be out in front of it, and it'll all be over.

I closed my eyes, held my breath, and waited until I felt the rush of air as the bus went past.

At the airport, I mentioned to my mother how upset I'd been feeling. She suggested that perhaps my antibiotics were to blame.

What? How can a substance built to kill bacteria make you unhappy? But I pulled out my phone, and googled for something along the lines of "antibiotics that cause depression" (I can't remember the exact term now) and found a list of drugs suspected to cause depression. And there at the bottom of the list was metronidazole, what I'd been taking for the last five days.

So that's it? I nearly threw myself under a bus because I was taking some stupid orange pills? How fragile and subjective our grip on reality is.

I write this on Friday night. Tomorrow I may stop taking the pills. I'll write and tell you what happens.

Written Sunday, September 3rd.

Saturday things got steadily better -- I had a great morning and afternoon. Towards the evening I thought I could feel my tooth getting worse, so I chickened out and took the pills again, and my mood seemed reasonably unchanged, so I took another before bed (the stated dosage is 3 per day, so 2 should be okay). But this morning things seemed crap again, so I didn't take one this morning, and 15 hours after my last dose the world seems fine again.

It seems crazy to me now that I was thinking about suicide just two days ago. My life is great! What the hell was I complaining about? So that's why I wrote it down then, as I knew the memory would fade. But that seems to be the effect these drugs have on me. Metronidazole turns up repeatedly, along with other antibiotics on lists of drugs that cause depression, such as the antibiotics used to treat acne, which are being reviewed for public use because of the link to depression after even the manufacturers began to list depression as a possible side effect.

In the states metronidazole is sold as Flagyl, and depression is sometimes listed by the retailer as a side-effect, and sometimes not. The leaflet that came with my own dose certainly doesn't. But the link to metronidazole specifically turns up in at least two medical studies as well as (obviously anecdotal, but still not to be dismissed) voluntary reports by patients.

Of course, since my teeth were painful as well as infected, I was also taking nurofen. Ah, glorious nurofen. Everybody takes that. Except nurofen is ibuprofen, and also lists depression as a side effect. Now a little suspicious, I did some googling, but no, you can't just find crazy people on the Internet claiming everything causes depression -- neither aspirin nor piriton, which I've taken in the past for headaches and hayfever respectively, for example, show any such link.

This is me. I don't even drink alcohol because the whole concept of a substance altering my mental state is repulsive to me. To discover that I've been happily swallowing not one but two substances, at the same time, which had such a profound effect on my mental state is shocking to me. To have it laid so bare that our whole grasp of reality is so totally subjective is also deeply scary. To say nothing of annoying, since I've blown a week of vacation in a (prescription) drug-fueled haze of crushing depression.

So kids, what have we learned? Well, I think that "dentists don't ever know what the fuck they're doing" is probably a good one. "Don't exceed the stated dose" might also feature, except I was following the directions, they just failed to mention all the side-effects. The best one is probably "deeply question your mental state before doing anything significant", I think. But I'm back to normal now, so you don't have to worry about me holding up the traffic anytime soon.