In Spain you used to say Petarda ir Petardo to people not able to use the brain properly, for example, if you drive under the effects of drugs or a lot of alcohol you are a petardo, if you say something without good judgement you are a petardo todo.
Synonyms of petarda are tonta tonto cateto
Used in Spain as well
"Que tía más petarda! Deberia usar mejor su cerebro"