When allergies flare up, it can be tempting to take an extra cetirizine tablet if the symptoms do not settle. But more frequent use does not necessarily mean better relief and can increase the risk of side effects.Dr Amit Saraf, director, Department of Internal Medicine, Jupiter Hospital, Thane, says cetirizine is generally taken once a day at the recommended dose.“Taking an extra dose occasionally does not necessarily cause serious harm in a healthy adult, but repeatedly taking it more often than advised can increase the risk of side effects, particularly excessive drowsiness, dizziness and impaired alertness,” he says.The appropriate dose and duration can also vary depending on a person’s age, kidney function and other medicines they may be taking. “If allergy symptoms are not settling, it is better not to increase the frequency simply because symptoms persist. Persistent symptoms may need a different treatment approach,” Dr Saraf adds.DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.Can cetirizine make you sleepy?“The most common side effect is drowsiness or fatigue, although cetirizine is considered less sedating than older antihistamines,” says Dr Saraf.Some people may also experience dry mouth, headache, dizziness or gastrointestinal symptoms. The potential for sleepiness is particularly important for people who drive, operate machinery or have jobs that require sustained concentration. Someone may not realise how strongly the medicine affects their alertness until after taking it.Story continues below this ad“If someone develops marked sedation or unusual symptoms after taking it, they should speak to their doctor rather than continuing to increase the dose,” Dr Saraf says. How frequently should you have Cetirizine (Photo: Representational/Magnific)Does cetirizine stop working if you take it regularly?There is a common concern that taking an antihistamine regularly can make it stop working. However, Dr Saraf says there is no strong reason to conclude that cetirizine routinely becomes ineffective simply because someone has used it for a long time.“There is no strong reason to say that cetirizine routinely ‘stops working’ because a person has taken it for a long time,” he explains.The bigger concern, he says, is taking any medicine continuously without checking whether it is still necessary or whether the underlying allergy requires a different treatment strategy.Story continues below this adThere is also another consideration for people who have been taking cetirizine every day for a prolonged period. Some people can develop intense itching within days of stopping it, although this withdrawal reaction appears to be uncommon.“Long-term daily use has also been linked to a rare withdrawal reaction: some people develop intense itching within days of stopping cetirizine after prolonged use,” says Dr Saraf.ALSO READ | Medication and blood sugar: Why same drug can affect people’s glucose levels differentlyWho should be more careful with cetirizine?Not everyone processes medicines in exactly the same way. Older adults and people with reduced kidney function need particular caution because cetirizine is cleared mainly through the kidneys.“It may accumulate when kidney function is impaired,” Dr Saraf explains. People who are already taking other medicines that cause drowsiness should also be cautious because the sedating effects may add up.Story continues below this adThose who drive or operate machinery should pay attention to how cetirizine affects their alertness before doing so.“Frequent use in children, pregnant women or people with significant kidney disease should ideally be discussed with a doctor rather than managed through repeated self-medication,” Dr Saraf says.DISCLAIMER: This article is based on information from the public domain and/or the experts we spoke to. Always consult your health practitioner before starting any routine.