I am one of those lucky people who do not have allergies and rarely has a cold, so I am not generally up on the latest and greatest over the counter (OTC) remedies for sufferers. However, this is a frequently asked question, so with the help of Divers Alert Network, I hope to shed a little light on this.
I have heard more than one diver complain recently about their allergies, especially in the spring. In an allergy sufferer, an allergen, such as pollen, is inhaled in through the nose, causing the mast cells to release histamine. Histamine release causes a lot of fluids to be produced, resulting in runny nose, tearing eyes, congestion and sneezing, all in an effort to flush that invader out of the body. The bad thing is that once one allergen particle is flushed out, surely another will enter, reigniting the cycle.
Antihistamines are readily available over the counter, but it is important to remember that even OTC medications have unwanted side effects. Side effects of antihistamines include drowsiness, dry mouth, blurred vision and increased heart rate. Increased heart rate can result in greater excitability in a diver, in some cases increasing the risk of panic. Drowsiness can be particularly troublesome for divers, since it can be heightened by nitrogen narcosis. If you are someone who experiences drowsiness when taking antihistamines, you may have better luck with a non-sedating agent, such as Claritin or Allegra.
If OTC antihistamines become ineffective in mitigating the symptoms, some doctors prescribe inhaled steroids. This medication, sprayed up the nose, acts locally and therefore does not have the troublesome side effects of medications that act systemically. The down side, however, is that it takes several days of treatment for them to work, so it requires some preplanning if a diver intends to use them on a dive trip.
Sinus congestion and its accompanying discomfort when diving can be the body’s response to a cold. In an effort to get as much of the body’s infection fighting tools, such as antibodies,and white blood cells, to the site of assault, blood vessels dilate, essentially opening the flood gates so all of our body’s helpers can stream to the site of the infection on a river of fluids. The result is a gunked up head.
Decongestants containing sympathomimetic agents, such as Sudafed (pseudoephedrine), cause the blood vessels in the nose to shrink, thus closing the flood gates and relieving symptoms. However, they can also increase heart rate and blood pressure. Again, the danger with increased blood pressure and heart rate can make a diver feel “jittery” and less able to deal with problems underwater without panic. These types of medication should be taken 30 minutes before diving, and care should be taken to assure that the formulation chosen will act for the full duration of the dive(s). Alternatively, there are nose sprays that are very effective in opening sinus passages that will not cause the jitteriness, but as they cannot be used for more than 3 days in a row, they may not be the solution if a diver is experiencing symptoms while on a dive trip.
It may be necessary to take some medications to save a dive or dive vacation, but caution should be exercised when using them. Ideally, a diver should try a medication and monitor the side effects on dry land before attempting to try it while diving. Even if no side effects are noted during the trial, still remain alert to them on any dive, as the effect of diving on the way medications react in the body are not fully understood. It is also important to investigate any possible interactions between OTC meds and prescriptions taken. For more information, check the Divers Alert Network website, your local pharmacist, or your physician for the best up to date advice.