My wild ride with duloxetine 120mg
Hey all, a few months ago I wrote the comment below to a post in this group and I want to share it again with some updates:
I want to share the digestive and sleep issues I've had during the past 2 years on Cymbalta (duloxetine) with anyone who may be experiencing something similar because I know how frustrating it can be to know what questions to ask and where to find answers. Ofc, this is completely my guesswork and physiology, so don't rely on what I'm sharing to be the same for you, and always talk to your doctor. After many doctors appointments, tests, and research, here's what I figured out (note I had been taking 120mg in the mornings with breakfast):
- Cymbalta (duloxetine) affects serotonin (S) and norepinephrine (N). The increased levels of S and N can have a combined effect, 1 may have a more dominant effect, or they may "take turns" in having a dominant effect
- S is associated with activating bowel movements and nausea (for me it was diarrhoea, gastritis, dramatic weight loss (4kg, ~9lb), nausea) whereas N is associated with constipation (if N levels are increased, then that tenses up the "flight or fight" response and also regaining the weight back plus another 1kg / 2lbs or so)
- About 95% of S is in the gut and N is in the sympathetic nervous system ("flight or fight" system)
- At first, my symptoms were more aligned with the effects from S, but then about 7-8 months later, N seemed to have a more dominant effect, which likely contributed to me developing SIBO at that point due to constipation
- I've had terrible sleep since day 1 of medication, and both artificially increased levels of S and N can negatively effect sleep, especially N since that's supposed to keep you alert
Here's what I've done broken down by what I think are my S-dominant period and N-dominant period:
S-dominant period (first 7-8 months on 120mg Cymbalta (duloxetine)):
- Blood tests - came back normal
- CT scan - mild fecal loading, mild superior mesenteric artery syndrome (likely due to rapid weight loss), all else normal
- Gastroscopy - mild gastritis, all else normal
- Prescribed PPI's, but I didn't take them due to the risks
- I basically gave up and figured things would sort themselves with more time (dumbass me)
N-dominant period (most recent 8 months until now on 120mg Cymbalta (duloxetine)):
- Saw a sleep specialist to rule out any physical or neurological conditions, eg sleep apnea, but I had none of those. She suggested I try CBT-I therapy and sleep hygiene. Did not work for me.
- Appointment with my psych to discuss the effects of duloxetine, re both stomach and sleep issues. Because I was being seen by a GI, he decided to focus on the sleep issues and prescribed me melatonin. Did not work for me.
- MRI - mild fecal loading, all else normal
- SIBO breath test - hydrogen dominant SIBO which is usually causes diahrrea, but in my case I have constipation
- Prescribed antibiotics to take 3 times a day for 2 weeks followed by a 2 week period before taking probiotics (Symprove for 2 weeks then Bio-Kult for another 2 weeks)
- Saw a dietician to support with symptoms and focus on a low FODMAP diet, but she was more concerned with me gaining weight first. I understand that she saw this as more urgent, but as a result, my symptoms continued
- Flexible sigmoidoscopy - everything came back normal
- Second SIBO breath test - again, hydrogen dominant SIBO
- Took the same antibiotics again and followed up with probiotics - this time 6 weeks of Symprove and 6 weeks of I also tried sticking to a low FODMAP diet but it's a pain in the ass because you can't eat garlic and onions which are in everything and there's no easy way to remember what's low or high FODMAP, for example - 2 green vegetables like spinach is low FODMAP but broccoli is high FODMAP. There's no easy rule to know!
- Call with the psych to try a new strategy for the insomnia. At this point it had been 22 months of no sleep every night I’m not kidding. At most I’d have 4 hours of sleep each night but those 4 hours were scattered. He prescribed me zoplicone 7.5mg which is a sedative that should rebalance circadian rhythm. Took it every night for 2 weeks then tapered off for another 2 weeks - ie one night off then on then 2 nights off then 1 on etc. It should be taken for no more than a month. Guess what, that did not work.
Where am I at now? Based on my research, I pushed my psych to agree to lowering my 120mg Cymbalta (duloxetine) dose down to 90mg for 2 weeks before moving to and staying at 60mg. I’m only 3 days into the 90mg and have no side effects (…yet). Maybe the side effects will occur when I drop to 60mg. I take it for depression and anxiety, and apparently there’s no therapeutic benefit to taking more than 60mg for my conditions.
I hope this post helps anyone who may be facing similar experiences. If so, I recommend researching the effects of S and N on digestive and sleep issues and discussing them with your doctor. My psych staunchly believed that Cymbalta (duloxetine) can in no way cause this level of insomnia, but I had to push.