Betablockers

[gozumutti]

I take betablockers as an anti-migraine treatment. Is there any info on the effects of betablockers and diving?

gozumutti

 

[John Reinertson]

This has been covered at some diving medicine conferences. Beta blockers can exacerbate asthma in people prone to bronchospasm. If you're not in this group, it's not a major factor. Beta blockers can reduce athletic performance somewhat. If you're fit, you'll still have adequate athletic reserve to respond appropriately to an emergency.

It's worth noting that while some diving requires very little athletic effort, a diving emergency can require a good deal of athletic emergency and it behooves us all to prepare for it with good general fitness. This is not to say I take my own advice as well as I should, but the idea is sound.
I know of no other problems offhand with beta blockers. Scubamed.com has some info on it and I'm sure there's a section in Dr Campbell's web site on it. If I were diligent, I would have checked Dr campbell's site first and I could then quote him appropriately.... again I don't always take my own advice.

John Reinertson

 

[gozumutti]

Thank you Dr. John, I will check out scubamed.com

gozu

 

[scubadoc]

As usual, John has stated the case well for/against beta blockers and diving. I suspect that the dangers of diving on beta blockers are real in those individuals who have severe heart problems or hypertension who require these large doses of the drug. In these cases the inability of the heart muscle to respond with an increase in the pulse rate to supply the myocardium with oxygen might be all that's needed to tip the scales into a situstion of acute pulmonary edema (heart failure). These people probably should not be diving to start with.

However, there are many who are taking the medication in smaller doses and for other reasons (as you are) who probably are not in any danger at all.

If concerned, you can always check out your ability to respond to stress or exercise by getting a treadmill test while on the medication.

Beta blockers also can cause a condition similar to Reynaud's Syndrome - decreased blood supply to the ends of the fingers and as Dr. Reinertson has stated, can worsen asthmatics due to bronchospasm.

In addition to it's beneficial effects on the heart and hypertension, beta blockers possess numerous mechanisms that may contribute to its efficacy in preventing migraine headaches. Beta-blockade can prevent arterial dilation, inhibit renin secretion, and block catecholamine-induced lipolysis. Blocking lipolysis decreases arachidonic acid synthesis and subsequent prostaglandin production. Inhibition of platelet aggregation is due to this decrease in prostaglandins and blockade of catecholamine-induced platelet adhesion. Other actions include increased oxygen delivery to tissues and prevention of coagulation during epinephrine release. Some of these actions can be seen to appear beneficial to divers.

Fred Bove, MD, imminent cardiologist, diver, and author of 'Diving Medicine' feels that the problem is over-stated, will rarely interfere with diving but that divers should be advised that extreme exercise response will be inhibited.

As with numerous other situations concerning various conditions, medications and diving - cautionaries need to be given but tempered with a good dose of reality - since we really don't have good RCTs to back up our advice.

scubadoc

***BillP's Disclaimer
http://www.scubaboard.com/showthread.php?threadid=570

 

[gozumutti]

Dear scubadoc

Thank you for all the info. I have concluded, from your comments, those of John Robertson and those on the scubamed site, that I need have no worries.

My heart is in good shape, the beta-blockers are only for migraine, and I take the the tablets with the lowest dosage available and HALVE those....this should not interfere with diving, from what I have gathered here.

Thanks again for the information.

gozumutti