Over-the-counter antihistamines

Some products cause marked sleepiness, while products labelled non-drowsy can still affect certain people. Read the active ingredient and directions rather than relying only on the brand name.

Antihistamine tablets may help sneezing, itching and a runny nose. Eye drops or nasal products act at a specific site and may suit symptoms limited to the eyes or nose. Combination cold-and-allergy remedies can contain an antihistamine plus other medicines that are not suitable for everyone.

Sedating antihistamines can impair reaction time, concentration and coordination. This matters before driving, operating machinery or doing safety-sensitive work, and alcohol can worsen the effect. A pharmacist can check the ingredient against your medicines and medical conditions.

Follow the package directions, use the supplied measuring device for liquids and avoid taking two remedies containing the same antihistamine. Check before use in a young child, during pregnancy or breastfeeding, or if you have glaucoma, difficulty passing urine, liver or kidney problems.

Review what is triggering the symptoms as well as treating them. Repeated exposure to pets or house dust mites may call for a broader management plan. If one correctly used product does not help, seek pharmacist or clinician advice instead of increasing the dose yourself.

Get urgent help for swelling of the tongue or throat, breathing difficulty, wheezing, faintness or collapse. An oral antihistamine is not a substitute for adrenaline and emergency care when anaphylaxis is suspected.

Arrange a routine assessment when symptoms keep returning, disrupt sleep, have no clear trigger, or remain troublesome despite correct use. New palpitations, severe dizziness, confusion, trouble urinating or pronounced drowsiness after a dose also warrant prompt medical advice.

Bring a list of prescription medicines, supplements and other cold or allergy products. Ask whether the chosen ingredient may make you sleepy, whether a local eye or nasal treatment is more appropriate, and how long to try it before your symptoms should be reassessed.