Morphine and Nocturnal Bradycardia

[Gibbel]

By using a small dose of morphine (3 tablets of 10 mg morphine sulfate), I have managed to taper off pramipexole, which had led to severe augmentation. It has been a tough process, almost without sleep for months.

I have now slowly titrated up on pregabalin, and I currently take 300 mg a couple of hours before bedtime, along with 1 tablet of morphine (10 mg morphine sulfate). While my night-time symptoms (I only have symptoms at night) are not completely gone, they have lessened significantly, allowing me to occasionally get 3–4 hours of sleep in the early morning.

However, I no longer dare to take the morphine tablet, as I’ve read that even a low dose of morphine can affect heart rhythm, which I already experience at night (nocturnal bradycardia). I am now 99.9% sure that as a result, I had a TIA (transient ischemic attack) about four weeks ago, likely caused by the morphine. The symptoms were identical to a cerebellar stroke I experienced five years ago: sudden, very intense nausea with vomiting, as if struck out of the blue. This was followed by severe nausea over the following weeks, during which I couldn’t eat anything and could only drink buttermilk with protein powder. (A nurse told me during my hospitalization five years ago that the “nausea center” is located in the cerebellum.)

My doctor, whom I visited 14 days after the sudden vomiting and persistent severe nausea, thought it might just be a common side effect of morphine. She did not respond to my suspicion of a possible TIA!

Now, after four weeks, the nausea has completely subsided, and I can eat normally again. However, my sleep remains limited.

Does anyone have advice on potential medication? Should I try increasing the pregabalin dose (I am 83 years old)? I am only willing to take the very small dose of morphine (1 tablet of 10 mg morphine sulfate) and feel uneasy about even that. Are there any opioids or similar medications that do not affect heart rhythm?

I take a sufficient dose of iron every other night and follow various good advice on diet, exercise, etc. Any advice would be greatly appreciated.

Gibbel

[SueJohnson]

Congratulations on getting off pramipexole! All opioids have generally the same side effects so changing to another one won't work. I would increase the pregabalin by 25 mg every couple of days. The usual maximum is 450 mg although you can go up as high as 600 mg.

[SueJohnson]

On the pregabalin, I assume you have been on it for at least 3 weeks and you have been off the pramipexole for several weeks and the withdrawal symptoms have settled. If not then wait until that occurs before increasing the pregabalin.

[Joolsg]

Buprenorphine works in a slightly different way to morphine. It is therefore less likely to cause respiratory depression and may not affect your heart rhythm.However, opioids can cause severe nausea. I certainly experienced a week of severe nausea when I first took Buprenorphine.

You could discuss it fully with your doctor. It might settle the night time RLS and give you more sleep.