Essential tremor and beta blockers

[The Laconic]

I was diagnosed with essential tremor today. I'm totally fine it, since I had expected much worse. But I'll be controlling it with beta blockers for the rest of my life.

So the questions are: is this going to limit my diving? Is diving on beta blockers safe? (I'm taking low doses of propranolol now, 5-10 mg as needed, but checking out some alternatives like atenolol.) Do I need to drop the cave diving and stick to good old Caribbean open water diving? Should I take it up with DAN? I'm in Chicago, and don't expect we have too many experts in dive medicine around here.

Any well-informed advice is appreciated.

 

[Duke Dive Medicine]

Hi Laconic,

In general, beta blockers are not a hard stop for diving, but your individual physical condition and reaction to the medication need to be evaluated. Get in touch with the hyperbaric unit at Swedish Covenant. They have physicians there who can perform fitness-to-dive evaluations. They're also the primary chamber in your area for diving injuries.

Best regards,
DDM

 

[Beau640]

warning: I am not a dive medicine doctor but I am an emergency medicine physician.

Duke Dive Medicine is the best around and I'd listen to their recommendations. Essential tremor in general is a pretty common condition and propranolol is usually the first line treatment. It's mechanism of action can cause slower heart rates and reduced blood pressure although the dose for essential tremor tends to be low and doesn't usually cause issues. I would take duke dive medicine's advice and be evaluated to ensure you don't have reduced exercise tolerance and are not having periods of decreased heart rate or low blood pressure which could adversely effect you while diving.

 

[DocVikingo]

Hi The Laconic,

5-10 mg indeed does seem to be a very small dose of propranolol, although the meaning of "as needed" in the OP is not clear to me. To the best of my knowledge beta blockers, including propranolol, are generally not intended to be taken on an as-needed basis, including with essential tremor which is chronic and most often progressive. They are occasionally so prescribed for anxiety attacks or for tremor reduction during specific activities. Perhaps the doctor is planning on observing response to such a regimen and altering the dosage as the clinical picture directs.

In any event, at 5 mg-10 mg, even if taken several times a day, efficacy would be questionable and side effects (such as reduced exercise tolerance) not normally anticipated. Even at considerably higher doses (initial dosage typically is 40 mg twice daily; optimum reduction of tremor is usually attained at 120 mg per day; in some persons, it may be necessary to up it to 240 mg-320 mg per day) only about 50-70% of patients report significant reduction in tremors, although some do get remarkable relief, others report no meaningful benefit. Side effects are dose- dependent and can include a number of GI problems (e.g., vomiting, diarrhea, stomach cramps), tiredness, dizziness, sleep problems, and sexual drive and performance issues. As with all drugs, a beta blocker should be given an adequate topside trial to assess for problematic side effects before attempting scuba. The patient should of course monitor for such and report any apparent adverse reactions to the treating source.

Turning to the matter of alternative drugs, specifically atenolol (also a beta blocker). As far as I am aware atenolol does not offer any significant increase in efficacy or safety, although it does appear that patients subjectively prefer propanolol. If one is interested in an alternative med, primidone (an anitconvulsant), either singly or in combination with propanolol, has been shown be effective in tremor reduction, although its side effects profile closely resembles that of propanolol and therefore may also be problematic.

As for return to diving at present, easy recreational diving not involving high levels of exertion would not appear to be contraindicated provided that tremors and any side effects of propanolol do not meaningfully interfere with the requirements of safe diving. Return to technical scuba, such as cave diving, strikes me as a different ball game, and a formal fitness to dive work up would seem prudent.

Regards,

DocVikingo

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such.

 

[The Laconic]

In any event, at 5-10 mg, even when taken several times a day, efficacy would be questionable and side effects (such as reduced exercise tolerance) not normally anticipated.

Perhaps my tremors are milder than I'd thought, or perhaps they're just on their way to getting worse. 5 mg twice a day (and then a couple of beers after work--normal consumption, an incidental benefit) is enough to stave them off on most days, together with cutting my caffeine intake by more than half. Some days I have to tack on another 10 mg. I've been easing into it because I wasn't happy jumping in at even a 10 mg dose (fogginess, cold hands and feet). But I haven't noticed any side effects at all now that I'm adjusted to these doses. Primidone was far worse--I took one dose and could barely function at work--although I've been told not to rule it out in the future.

I've been exercising in the meantime. I don't know whether I have reduced tolerance or whether I've just always hated it this much.

An evaluation at Swedish Covenant sounds prudent before cave diving. Thanks everyone!

 

[DocVikingo]

...5 mg twice a day (and then a couple of beers after work--normal consumption, an incidental benefit) is enough to stave them off on most days, ....

I've long been impressed at how much relief many patients with essential tremor can get from modest ETOH consumption, and I recommend it fairly often under appropriate circumstances. Too bad it's not a very practical solution when one is working, driving, diving, etc.

Cheers,

DocV

 

[high/baric]

I find it a little surprising how relaxed the attitudes towards propranolol are on these forums. Although I do not do fitness to dive evaluations routinely, it is my understanding that regular use of non-selective beta-blockers is a contraindication to diving. Not only do they adversely affect physical performance, but being non-selective they also have considerable affinity to beta2 receptors and can cause (clinically) significant broncospasm. I must admit that some of the diving physicians I know and have heard this from can be a bit strict (such as considering color blindness a contraindication to all types of SCUBA diving for the fear that such a person could ultimately become interested in deep rebreather diving and confuse indicator lights on the machine due to his condition). The latest edition of Diving and Subaquatic Medicine recommends respiratory function testing to rule out possible broncospasm with patients on any beta blockers. Then again the dosage you have been prescribed is modest and probably can be used on an as-needed basis. I'd be interested to know what your physician ultimately thought about cave diving, if you don't mind sharing.

 

[Beau640]

They cause bronchospasm in people that have reactive airway disease. If you don't have a history of copd or asthma they shouldn't be a problem from a respiratory standpoint.

Again, like I had said before, another reason to see a physician first just to ensure you'll be safe diving on them.

 

[Duke Dive Medicine]

I find it a little surprising how relaxed the attitudes towards propranolol are on these forums. Although I do not do fitness to dive evaluations routinely, it is my understanding that regular use of non-selective beta-blockers is a contraindication to diving. Not only do they adversely affect physical performance, but being non-selective they also have considerable affinity to beta2 receptors and can cause (clinically) significant broncospasm. I must admit that some of the diving physicians I know and have heard this from can be a bit strict (such as considering color blindness a contraindication to all types of SCUBA diving for the fear that such a person could ultimately become interested in deep rebreather diving and confuse indicator lights on the machine due to his condition). The latest edition of Diving and Subaquatic Medicine recommends respiratory function testing to rule out possible broncospasm with patients on any beta blockers. Then again the dosage you have been prescribed is modest and probably can be used on an as-needed basis. I'd be interested to know what your physician ultimately thought about cave diving, if you don't mind sharing.

We do not consider them an absolute contraindication, but anyone on beta blockers who wants to dive should first be evaluated by a physician who is trained in examination of divers. Exercise tolerance tends to improve over time in most people, but individual response to the medication needs to be evaluated in the context of expected/possible levels of exertion, including reacting to emergencies or unanticipated situations like higher-than-expected currents.

Best regards,
DDM