Hydroxyamphetamine may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Normethadone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Eszopiclone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Ziprasidone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Lormetazepam is combined with Cetirizine. The risk or severity of adverse effects can be increased when Acepromazine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Alaproclate. The risk or severity of adverse effects can be increased when Butethal is combined with Cetirizine. The risk or severity of adverse effects can be increased when Dyclonine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Levobupivacaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Zopiclone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Carfentanil is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Guanfacine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Milnacipran. The risk or severity of adverse effects can be increased when Carbamazepine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Butamben is combined with Cetirizine. The risk or severity of adverse effects can be increased when Osanetant is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Brompheniramine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Doxepin. The risk or severity of adverse effects can be increased when Ketazolam is combined with Cetirizine. The risk or severity of adverse effects can be increased when Hydromorphone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Butalbital is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Carbinoxamine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Fluticasone propionate. The risk or severity of adverse effects can be increased when Etorphine is combined with Cetirizine. MMDA may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Clemastine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Levodopa. Chlorphentermine may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Brexpiprazole. The risk or severity of adverse effects can be increased when Eltanolone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Oxprenolol is combined with Cetirizine. The risk or severity of adverse effects can be increased when Desflurane is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Felbamate. Cetirizine may increase the central nervous system depressant (CNS depressant) activities of Suvorexant. The risk or severity of adverse effects can be increased when Pimozide is combined with Cetirizine. The risk or severity of adverse effects can be increased when Butorphanol is combined with Cetirizine. The risk or severity of adverse effects can be increased when Quetiapine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Reserpine is combined with Cetirizine. Hydroxyzine may increase the central nervous system depressant (CNS depressant) activities of Cetirizine. The risk or severity of adverse effects can be increased when Gepirone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Protriptyline. The risk or severity of adverse effects can be increased when Lorazepam is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Maprotiline. The risk or severity of adverse effects can be increased when Cetirizine is combined with Vigabatrin. Methamphetamine may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Diphenoxylate is combined with Cetirizine. The risk or severity of adverse effects can be increased when Morphine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Trans-2-Phenylcyclopropylamine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Lidocaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Chloral hydrate is combined with Cetirizine. The risk or severity of adverse effects can be increased when Remifentanil is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Ethotoin. The risk or severity of adverse effects can be increased when Chlordiazepoxide is combined with Cetirizine. Mephentermine may decrease the sedative activities of Cetirizine. The therapeutic efficacy of Betahistine can be decreased when used in combination with Cetirizine. Dronabinol may increase the central nervous system depressant (CNS depressant) activities of Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Amoxapine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Flunarizine. The risk or severity of adverse effects can be increased when Amisulpride is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Carisoprodol. The risk or severity of adverse effects can be increased when Cetirizine is combined with Clonazepam. The risk or severity of adverse effects can be increased when Promazine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Secobarbital is combined with Cetirizine. The risk or severity of adverse effects can be increased when Articaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Triprolidine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Scopolamine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Pipotiazine. The risk or severity of adverse effects can be increased when Hexobarbital is combined with Cetirizine. Perampanel may increase the central nervous system depressant (CNS depressant) activities of Cetirizine. Dextroamphetamine may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Cyclizine. The risk or severity of adverse effects can be increased when Prochlorperazine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Perospirone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Ziconotide. Minocycline may increase the central nervous system depressant (CNS depressant) activities of Cetirizine. Cetirizine may increase the sedative activities of Ropinirole. The risk or severity of adverse effects can be increased when Loprazolam is combined with Cetirizine. The risk or severity of adverse effects can be increased when clomethiazole is combined with Cetirizine. The risk or severity of adverse effects can be increased when Proparacaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Pomalidomide. The risk or severity of adverse effects can be increased when Oxethazaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Alphacetylmethadol is combined with Cetirizine. Cetirizine may increase the central nervous system depressant (CNS depressant) activities of Mirtazapine. The risk or severity of adverse effects can be increased when DPDPE is combined with Cetirizine. The risk or severity of adverse effects can be increased when Diazepam is combined with Cetirizine. Magnesium Sulfate may increase the central nervous system depressant (CNS depressant) activities of Cetirizine. The risk or severity of adverse effects can be increased when Fencamfamine is combined with Cetirizine. Benzphetamine may decrease the sedative activities of Cetirizine. Cetirizine may increase the central nervous system depressant (CNS depressant) activities of Zolpidem. The risk or severity of adverse effects can be increased when Cetirizine is combined with Tetrabenazine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Dimenhydrinate. The risk or severity of adverse effects can be increased when Levorphanol is combined with Cetirizine. 3,4-Methylenedioxyamphetamine may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Ethylmorphine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Pentobarbital is combined with Cetirizine. The risk or severity of adverse effects can be increased when Mepivacaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Perazine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Etoperidone. The risk or severity of adverse effects can be increased when Flunitrazepam is combined with Cetirizine. The risk or severity of adverse effects can be increased when Fludiazepam is combined with Cetirizine. The risk or severity of adverse effects can be increased when Tetracaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Iloperidone. The risk or severity of adverse effects can be increased when Tetrodotoxin is combined with Cetirizine. The risk or severity of adverse effects can be increased when Amobarbital is combined with Cetirizine. The risk or severity of adverse effects can be increased when Ritanserin is combined with Cetirizine. The risk or severity of adverse effects can be increased when Melperone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Fentanyl is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Levocetirizine. The risk or severity of adverse effects can be increased when Buspirone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Meclizine. The risk or severity of adverse effects can be increased when Cetirizine is combined with Trimipramine. The risk or severity of adverse effects can be increased when Benzocaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Amitriptyline is combined with Cetirizine. The risk or severity of adverse effects can be increased when Amperozide is combined with Cetirizine. The risk or severity of adverse effects can be increased when Codeine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Triflupromazine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Olanzapine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Methylphenobarbital is combined with Cetirizine. Midomafetamine may decrease the sedative activities of Cetirizine. Amphetamine may decrease the sedative activities of Cetirizine. The risk or severity of adverse effects can be increased when Halothane is combined with Cetirizine. The risk or severity of adverse effects can be increased when Dihydroetorphine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Tramadol is combined with Cetirizine. The risk or severity of adverse effects can be increased when Isoflurane is combined with Cetirizine. The risk or severity of adverse effects can be increased when Chlormezanone is combined with Cetirizine. The risk or severity of adverse effects can be increased when Gamma Hydroxybutyric Acid is combined with Cetirizine. The risk or severity of adverse effects can be increased when Etidocaine is combined with Cetirizine. The risk or severity of adverse effects can be increased when Barbital is combined with Cetirizine. The risk or severity of adverse effects can be increased when Ethyl loflazepate is combined with Cetirizine.