Yes, taking 30 20mg Ceterizine Hcl tablets is an overdose. It is unwise to ever take more than the recommended dose of any medication, as this can cause adverse side effects.
I would also not recommend taking Cetirizine recreationally, as this can be very dangerous!
Risks of overdose
Ceterizine Hcl is an antihistamine which essentially treats the symptoms of hayfever such as a runny nose and sneezing and is available over the counter.
However, if the recommended dosage is exceeded individuals are likely to experience side effects such as extreme drowsiness, restlessness, nervousness and increased anxiety.
Side effects of Cetirizine
As mentioned previously, taking too many Cetirizine can result in extreme drowsiness. It is best not to drink alcohol when taking it or to take other medicines without consulting a doctor first.
It is particularly important to check with a doctor before taking this medication if you take other medications which are likely to make you drowsy too.
In the worst case scenario, an overdose could cause respiratory failure which could lead to serious complications, or even death!