Drugs and diving I

People nowadays learned to depend on drugs either routinely or intermittently to control diseases and to be able to cope with every day's life minor illnesses.


Diving environmental conditions such as cold, spatial disorientation, reduced visibility, inability to localize sound direction, narcotic effect of inert gases in the breathing medium, all of these could change dramatically the effect ( desired or undesired) of the drug taken by the diver.
Another way the drug can exert its effect upon a diver is by changing the rate of uptake or elimination of the inert gas , our best example is dehydration that is caused by certain drugs such as diuretics and alcohol increasing the incidence of decompression sickness.


One of the most common drugs is Aspirin, It interferes with blood clotting mechanism and increase bleeding tendency, an effect that is considered disastrous in inner ear embolism or severe inner ear decompression sickness.


Antihypertensive drugs are ingested by a considerable number of divers now , who were divers long before becoming hypertensive patients, this group of divers are middle aged, experienced divers, though having normal life stress, yet successful and very proud, if you are one of this group, please consult a hyperbaric medicine specialist about your medication, for example a common drug group are ß-blockers that is prescribed by cardiologists ,they have minimal side effects and are well tolerated by many patients, ß-blockers can cause inadequate heart response to exercise, an effect that could be critical in emergency dive situations.

Another example is oral contraceptives, the hormones that increase the coagualbility of blood predisposing to decompression sickness, so if you are a dive master, diving every day two or three dives, in a warm weather like Hurghada, you have to be very careful from getting dehydrated that adds to coagulability of blood and less efficient circulation predisposing to decompression sickness.
The List is long, there is too much that we do not know about how drugs can interact with our bodies in the hyperbaric environment
It can not simply become you are taking a drug you do not dive !!!
As drugs (natural or synthetic) have become a part of modern life, we have to understand how they act and use them safely while enjoying our dives.

Dr. Hanaa M. Nessim

Drugs and diving II

This time we will mention Recreational drugs, they are drugs, which may be legal or illegal to consume in the country you are living in, they are taken regularly or occasionally on social events, consumed to change mood or alleviate peer pressure. These drugs include Tobacco, Alcohol, Marijuana, Hashish
(Cannabis) and others.
To start with, the most common in use is Tobacco
The main active principal of tobacco is nicotine, the pharmacological generalized effect of which is raising blood pressure, increasing heart rate and restriction of blood flow to the heart muscle ( Coronary vasoconstriction). This obviously lowers physical fitness. (Can you swim 200 meters towing an unconscious diver?)



Inhalation of tobacco smoke containing nicotine and tar causes bronchospasm
( narrowing of respiratory passages ) as well as more mucus production by the tissue that lines these bronchi adding to more narrowing of Bronchial lumen, this leads to higher possibility of air trapping in lung tissue with the incidence of
pulmonary infection (bronchitis) getting very high, and the possibility
( not remote) of ascent pulmonary barotrauma due to partial air trapping inside the lungs and fatal air embolism.
A whisper for professional divers who are chronic smokers:
How many times last year have you suffered from chronic cough for several days with or without fever (Bronchitis) ?? If more than 2 times and not seasonal, then either quit smoking today or find another job.
To investigate your pulmonary functions, it is recommended to make a
Lung function test during your diving regular medical checks.
Tobacco smoking increases carboxy hemoglobin level to 5-9% in blood , which increases the viscosity of blood with less efficient blood circulation and more likelihood of decompression sickness.
I wish you safe diving.

Dr. Hanaa M. Nessim