The most frequent adverse effects reported with loratadine are nervous system effects. Adverse nervous system effects occurring in pediatric or adult patient receiving loratadine in clinical trials include hypoesthesia, asthenia, dizziness, dysphonia, hypertonia, migraine, paresthesia, tremor, vertigo, agitation, amnesia, anxiety, confusion, decreased libido, depression, impaired concentration, irritability, morbid dreaming, headache and sedation.