Hay fever season is finally upon us, and to combat the runny noses and itchy eyes caused by the pollen in the air many of us will opt to take eye drops, nasal sprays and antihistamines. However, despite these products helping to ease the symptoms of hay fever, what many people do not know is that they can have some very surprising side effects.

Find something that works best for you and your symptoms

Find something that works best for you and your symptoms

Fortunately, Dr Daniel Fenton, from London Doctors Clinic, has broken down the most common side effects of hay fever treatments is giving his advice for how to choose the right treatment for you.

What are the most popular hay fever treatments, and which are the most effective? For example, are antihistamine tablets more effective than nasal sprays?

The most popular hay fever treatments encompass a cocktail of antihistamine tablets, nasal sprays and eye drops.

The tablets you will see on the shelves include Loratidine (Clarityn), Cetirizine (Zirtek), Chlorpheniramine (Piriton) and Diphenhydramine (Benadryl).

They are very effective at providing an all-day benefit against pollen. The first two on the list are fairly long-acting, non-drowsy antihistamines. The latter two are drowsy antihistamines - some people avoid these due to their sedative effects, but should perhaps think twice. They are very effective and quick acting, but last for shorter periods of time, meaning you may need them 2-3 times a day. As a perennial hay fever sufferer, I utilise a non-sedative antihistamine during the day, and a sedative one at night time to help me sleep through the summer nights, with the window ajar and without sneezing all night.

If these fail to help, it is worth speaking with your GP. Fexofenadine (Telfast) is a fantastic antihistamine that is only available on prescription. In my experience is one of the most effective around.

Nasal Sprays are particularly helpful for the rhinitis (runny) or blocked nose symptoms, which antihistamine tablets may not always take care of.

Beconase is always a good start, but mometasone (Nasonex) or Fluticasone based sprays such as Avamys and Dymista, can provide that next step for relief.

The most important thing about nasal sprays is their correct use. They do not work immediately, and their effects are cumulative, meaning the longer you use them, the better the response - be patient.

Adding eye drops to your regime can be really useful to help combat the itchy eyes.

What are the most common side effects of hay fever medications, and why do they occur?

Whilst some antihistamines are marketed as "non-drowsy", some individuals are particularly sensitive, and will still find themselves experiencing some fatigue.

Some lesser known side effects include a dry mouth/throat, dry eyes and blurred vision. Medications that block histamine receptors help allergic conditions, but these types of medications can reduce mucous and aqueous production, which cause dry eye and mouth complaints.

Nasal decongestants are often combined with anticholinergic medications which together contribute to dry eyes, dilated pupils and decreased response to bright light. The dilated pupils interfere with your ability to focus on objects and can, therefore, contribute to blurry vision.

In some individuals, nasal sprays can cause some localised irritation within the nostrils, and cause nose bleeds.

Prolonged use of over the counter decongestant nasal sprays can create a rebound rhinosinusitis if used for too long – in essence, they can make symptoms worse if used for more than 2 or 3 days.

What should you do should you experience any of these symptoms?

If you experience any of these side effects, it is really important to discuss with your GP. There is a multitude of alternative antihistamines, spray and drops that may be more suited to you.

Alternatives even include using medications used in asthma, such as Montelukast, which is excellent for the runny nose component of hay fever. Using well-known antacids, like ranitidine - whilst most people associate their use with acid reflux and heartburn, they actually have a great antihistamine effect.

When all else fails, you may consider the hay fever injection, which is a steroid-based injection. This is not to be taken lightly, as is not without risks, but may be beneficial to the most severe of hay fever sufferers

How do you know which hay fever treatment is best for you?

The truth behind hay fever treatment is that it can be trial and error. You have to take the time to find the right combination of treatments for you. Speaking to your GP to your GP is useful as they will take you through all of the options and recommend, prescribe and administer hay fever medications as needed.

Dr Daniel Fenton is Medical Director at London Doctors Clinic.