Benzocaine

Odourless anaesthetic typically used locally for relief of oropharyngeal pain, can be found as a cutting/bulking agent due to appearance as a white powder, reported to have a bitter taste. A common adulterant in both illicit and licit psychoactive drugs. As a comparatively cheap chemical to produce with anaesthetic effect, it is commonly incorporated as a cutting or bulking agent in drugs of abuse in white powder form. Oral absorption is poor due to low water solubility, however ingestion may result in local anaesthetic effects in the oesophagus.

Numbing of the area relating to the route of exposure is common due to the chemical’s anaesthetic properties – this can often be masked by the drug of abuse it is combined with. Restlessness, confusion, drowsiness, weakness, shivering and muscle twitching leading to convulsions may occur following use. Additionally, hypotension with refractory tachycardia & arrhythmias may occur. Cyanosis (“blue” or “grey” skin) may develop due to methaemoglobinaemia risk. Toxicity may occur from sodium channel blockade