Emla Overdosage

Systemic toxicity is very unlikely with normal use of Emla. In the event of toxicity, the symptoms are expected to be similar to those seen after local anaesthesia treatment ie, excitatory central nervous system (CNS) symptoms and in severe cases, CNS depression and myocardial depression.
Rare cases of clinically significant methaemoglobinaemia have been reported (see Adverse Reactions). Prilocaine in high doses can increase the methaemoglobin level.
Topical administration of prilocaine 125 mg for 5 hrs caused moderate methaemoglobinaemia in a 3-month old child. Topical administration of lidocaine 8.6-17.2 mg/kg caused very serious intoxication in infants.
Severe neurological symptoms (convulsions, CNS depression) require symptomatic treatment eg, assisted ventilation and anticonvulsant therapy.
In the event of methaemoglobinaemia, methyl thionine is the antidote. On account of a slow systemic absorption, a patient with symptoms of toxicity should be kept under observation for several hours following any treatment of these symptoms.