Insomnia is a common side effect of hay fever, so if you need a little extra help getting to sleep during pollen season, your doctor might ask you to take a drowsy antihistamine before you go to bed. At therapeutic doses, no clinically significant interactions have been demonstrated with alcohol (for a blood alcohol level of 0.5 g/L). Nevertheless, precaution is recommended if alcohol is taken concomitantly. Every medication is different, so taking them together will pose different risks that your doctor will know all about. The apparent volume of distribution is 0.50 l/kg. Plasma protein binding of cetirizine is 93 ± 0.3 %. Cetirizine does not modify the protein binding of warfarin. Always be sure to follow your doctor's instructions and read all information provided to avoid such symptoms. Do hay fever tablets work?

After discontinuation of cetirizine, pruritus (intense itching) and/or urticaria have been reported. Carcinogenesis and mutagenesis: In a 2-year carcinogenicity study in rats, cetirizine was not shown to be carcinogenic at dietary doses up to 20 mg/kg (approximately 15 times the maximum recommended daily oral dose in adults). In a 2-year carcinogenicity study in mice, cetirizine administration lead to an incidence of benign liver tumors in males at a dietary dose of 16 mg/kg (approximately 6 times the maximum recommended daily oral dose in adults). The clinical significance of these findings during long-term use of cetirizine is unknown at this time . In a placebo-controlled study, cetirizine given at the high daily dose of 60 mg for seven days did not cause statistically significant prolongation of QT interval. diarrhoea – drink plenty of water or other fluids if you have diarrhoea. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor. If you are giving cetirizine liquid medicine to a child, make sure you follow the dosing instructions on the bottle carefully so that you measure out the correct dose for the age of your child.If your hay fever symptoms are really bad, you may occasionally need short-term relief. If this is the case, your GP may prescribe a short course of steroid tablets lasting between five to 10 days. Loratadine is a non-drowsy antihistamine, whereas Piriton contains Chlorphenamine, a drowsy antihistamine. Although there's currently no cure for hay fever, you can make certain tweaks to your lifestyle to help ease hay fever symptoms. Antihistamine tablets and liquids are available over the counter from a pharmacy without the need for a prescription. Antihistamine nasal sprays are only available on prescription. Antihistamines can be used on their own for mild cases of hay fever, or with other products. Your GP or pharmacist can advise you on what treatments are most suitable for you. Let’s start with non-drowsy. Here’s a list of antihistamines that are considered to be non-drowsy and which medications you can find them in:

If you forget to give a dose to a child who is taking cetirizine twice a day, you can give the missed dose if it's within 4 hours of when they should have had it. However, this is something only your doctor should suggest and is never something you should decide to do without speaking to them first.

Log in/register

Cetirizine, a human metabolite of hydroxyzine, is a potent and selective antagonist of peripheral H 1-receptors. In vitro receptor binding studies have shown no measurable affinity for other than H 1-receptors. There are also several treatment options available to help you manage your symptoms throughout hay fever season. Clinical studies have shown that cetirizine at the recommended dosage has minor undesirable effects on the CNS, including somnolence, fatigue, dizziness and headache. In some cases, paradoxical CNS stimulation has been reported. Cetirizine is known as a non-drowsy antihistamine. It's much less likely to make you feel sleepy than some other antihistamines. One method that's suitable for some people is immunotherapy treatment. This involves gradually introducing you to small amounts of your particular allergen and monitoring your reaction in a controlled environment.