Opinions from a couple of dive medicine experts on the atenolol:
1. Dr. Jules Eden:
"The common medical consensus is no you can't. The reason for this is that beta blockers such as atenolol or propranolol really reduce the heart's response to exercise. This wouldn't be too bad on terra firma but underwater it can create problems of fluid collection in the lungs called pulmonary oedema. There is also a risk of getting short of breath due to the drugs having a side effect of narrowing the bronchi of the lungs.
But having said that some diving doctors feel that if you can pass an exercise test and show that the medication has none of the above effects on you then you can be passed as fit."
2. Dr. Ern Campbell:
"Patients taking beta adrenergic blocking drugs may also have unique problems with exercise. These patients may have significant inability of the heart to respond to exercise; therefore, measurement of heart rate does not provide the index of exercise work load which is generally found in the patients who have normal autonomic responsiveness .
When stress testing a patient on beta blockade, a relative maximum heart rate can be achieved by comparing the perceived exercise score with the heart rate when the patient has significant fatigue. Heart rate response to exercise however, does not indicate a poor physiologic response in this case. There is some suggestion that beta adrenergic blockade will inhibit maximum exercise performance.
Diving should not provoke maximum work demand. However, it is important to advise divers taking beta blockers to avoid extreme exercise since their maximum capacity may by inhibited by beta blockade. Exercise testing should be done while taking the beta blocker and in the presence of the usual therapeutic regimen."
As you can see, both are conservative about diving while on a beta blocker.
Adverse reactions can include:
Serious Side Effects
Depression, shortness of breath, wheezing, slow heartbeat (especially less than 50 beats per minute), chest pain or tightness, swelling of the ankles, feet, and lower legs.
Common Side Effects
Decreased sexual ability; decreased ability to engage in usual physical activities or exercise; dizziness or lightheadedness, especially when rising suddenly from a sitting or lying position; drowsiness, fatigue, or weakness; insomnia.
Less Common Side Effects
Anxiety, irritability; constipation; diarrhea; dry eyes; itching; nausea or vomiting; nightmares or intensely vivid dreams; numbness, tingling, or other unusual sensations in the fingers and toes; abdominal pain; nasal congestion.
The possible adverse reactions involving compromised exercise tolerance, dizziness & signs/symptoms that could be confused with DCS seem of especial concern to the diver. If a diver experienced any of these features, they would want to inform their physician of such & seek renewed clearance to dive.
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. Seek clearance to dive from your physician.
Best regards.
DocVikingo
