The most dangerous effects of overdose of tramadol are pupillary  constriction, vomiting, respiratory depression and convulsions. If you  suspect a poisoning should immediately seek medical help. 
First aid for poisoning – the maintenance of adequate pulmonary  ventilation and symptomatic therapy in a specialized department. In mild  cases enough gastric lavage. Application of naloxone is not critical,  since does not resolve all the symptoms of poisoning and can cause  convulsions. Hemodialysis is ineffective. In convulsions appropriate  intravenous diazepam.

