Hay fever treatments – how do I decide the best product?

Oral antihistamines are a good place to start, especially if you have multiple symptoms. They aim to dampen down the overall immune response, which is driven by the release of histamine from mast cells. Starting antihistamines early is key to keeping symptoms under control, ideally a couple of weeks before your particular pollen season.

Once-daily antihistamines are available to buy and contain loratadine or cetirizine. They are similar in effectiveness, but you may find one works better than the other. Both get to work within 1 to 3 hours, cetirizine perhaps slightly faster, and both peak in effectiveness after 8 to 12 hours, but last for at least 24 hours – loratadine possibly longer. At this dose, they are unlikely to make you drowsy.

Older antihistamines are more likely to cause drowsiness – this may be an advantage if symptoms are worse at night, but not if you need to operate heavy machinery or drive long distances. Those containing chlorphenamine (such as Piriton) or promethazine (such as Phenergan) are older types. They work for a shorter amount of time, typically 4 to 6 hours, so you might need to take them several times a day or just when the pollen count is higher, typically early mornings and evenings. Despite this, some people think they work better for their particular hay fever – it's a question of trial and error what works for you.

These are the options available to buy over-the-counter. If they are ineffective, your doctor can prescribe fexofenadine, which is a stronger antihistamine.

You may want to treat a single symptom, such as a stuffy or runny nose, or just itchy or streaming eyes.

Sodium cromoglicate 2% products, such as Opticrom eye drops, are available over-the-counter for those aged 6 and above. This active ingredient is not classed as an antihistamine but works to reduce the release of histamine in the eyes and suppress allergy symptoms there. It’s applied four times a day, and can be used as a standalone treatment or alongside oral antihistamines.

The advantage of sodium cromoglicate is that it’s available to buy over-the-counter. Intranasal or eye drop antihistamines require a prescription, but may be preferred as they last longer, and therefore need applying less often.

Antihistamine eye drops such as Optilast (contains olopatadine) or Azelast (contains azelastine) only need to be applied twice daily, and the same with intranasal antihistamines, such as Rhinolast nasal spray (contains azelastine). Targeted antihistamine products can be prescribed for those aged 6 and over.

Steroid nasal sprays are available over-the-counter and contain either beclomethasone (found in Beconase hay fever spray), fluticasone (in Pirinase nasal sprays) or mometasone (in Clarinaze nasal spray). They are available for those over 18 – children need to have these prescribed after consideration by their doctor.

Both Pirinase and Clarinaze have similar effectiveness and potential for side effects. Both are slightly stronger than Beconase, and are often used once a day, instead of twice a day. It's down to personal preference and cost – the newer Pirinase and Clarinaze are usually more expensive.

Steroid nasal sprays take one to two weeks to build up to maximum effect, and they need to be taken regularly. You can start them a couple of weeks before you anticipate the pollen season starting, and they can be taken throughout, for up to 3 months. They are considered safe for adults and only a minute amount of steroid is absorbed into the body, so they do not carry the risks of taking steroid tablets.

While you wait the few days for a steroid nasal spray to get to work, you may seek short-term relief. A nasal decongestant such as Otrivine nasal spray or Vicks Sinex soother can relieve a blocked nose or sinuses within minutes. Nasal decongestant sprays don’t dampen down the immune response like steroids do, but instead they temporarily shrink blood vessels in the nasal passages, relieving the feeling of a stuffy nose. These should not be used for more than 7 days, as continual use can cause rebound congestion once you stop.

A decongestant tablet such as Sudafed (contains pseudoephedrine) can also rapidly clear the nasal passages. However, a tablet is more likely to interact with other medicines, and some may experience a racing pulse or palpitations, or increased wakefulness, as it has an adrenaline-like effect on the body.