We are all (hopefully) familiar with the air travel rules. Get to the airport two hours before your flight, don't have any liquids in your hand luggage over 100ml, and leave your knives at home.
But do you know what medicines you should and shouldn't take when you're on a plane?
According to pharmacist Nial Wheate in an article for The Conversation, taking certain medications when flying could be putting your health at risk.
Air travel can be pretty unpleasant, because you're cramped, the oxygen levels are lower than normal, and you can easily get dehydrated because of the lack of moisture in the air.
Aeroplane conditions can increase the risk of deep vein thrombosis (DVT), which is a type of blood clot that occurs in deep veins around the body, often the legs. In severe cases, this can result in blocked blood flow to the heart, lungs, or brain, causing a heart attack, aneurysm, or stroke.
The chance of developing a clot on a flight is about 1 out of every 5944 flights, so the risk is very small. But it's worth keeping in mind the medicines that also increase this risk, so you can avoid them where possible.
Some contraceptive pills for women carry a slight increased risk for developing blood clots, although it is small. Estrogen and other hormone-based fertility treatments can also increase the risk.
Wheate said that if you're at an increased risk already, then anti-platelet medication might be a good choice for you, such as warfarin or aspirin. Platelets are the components of blood which create blood clots, usually to stop bleeding.
Many people struggle to sleep on planes. They are uncomfortable and cramped, unless you're a business or first-class passenger.
This means sleeping pills are a popular option for getting enough shut-eye, especially if you're travelling long distances.
Unfortunately, this might also increase your risk of DVT. Knocking yourself out with a pill means you don't move around as much. It also lowers oxygen levels in the blood. Both of these increase the risk of DVT.
Smokers, obese people, pregnant women, or those who have recently had an operation are thought to be most at risk of DVT.
Wheate wrote that some people opt for antihistamines instead of sleeping pills, because they make you drowsy. In fact, parents often give antihistamines to their children to settle them down.
However, this is not recommended as it can sometimes have the reverse effect, and make children hyperactive. They might also cause depressed breathing, which isn't ideal when you're already experiencing lower oxygen levels.
Some people really hate air travel. The idea of flying through the air, thousands of feet from the ground, fills them with anxiety. Sometimes it is so bad, they have to be prescribed anti-anxiety medication just to make it through the journey.
According to therapist and airline captain Tom Bunn, who specialises in flight phobia, anti-anxiety medications on flights are inadequate, and come with a high long-term cost.
He wrote in a blog post for Psychology Today that anti-anxiety medications prevent anxious fliers from getting used to flying, they increase sensitivity to plane noises and movements, they impact the person's memory, and are addictive. Mixing the medication with alcohol can also be dangerous.
One study, published in the journal Behaviour Research and Therapy, found that people taking anti-anxiety drugs may feel more relaxed psychologically. But physiologically, their heart and breathing rates were much higher than people who took a placebo.
A week later, the same subjects were put on another flight without medication. 71% of those who had taken the anti-anxiety medication before had significantly increased anxiety, a desire to leave the plane, and panic. The group who had been given the placebo reported less anxiety on the second flight.
Instead, Bunn suggests anti-anxieties on flights simple numb the panic, but don't help much in the long-term. Rather, you have to tolerate some of the anxiety to be able to get rid of it.