This medicine is called: LMX4, Lidocaine 4%w/w Cream Each gram of cream contains 40mg of the active ingredient lidocaine. LMX4 is a type of medicine called a local anaesthetic, used to numb an area of the body. LMX4 temporarily numbs the surface of the skin. It can be used to provide pain relief when a needle is inserted into the skin for clinical purposes, such as into a vein (venipuncture or venous cannulation). It may also be used to numb the skin prior to administration of painful topical treatments on larger surface areas of intact skin.