Haloperidol, marketed under the trade name Haldol among others, is a typical antipsychotic medication. It may be used by mouth or injection into a muscle or a vein. When taken during pregnancy it may result in problems in the infant. It should not be used in people with Parkinson's disease. It was made from pethidine (meperidine). It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. It is the most commonly used typical antipsychotic. The yearly cost of the typical dose of haloperidol is about £20–800 in the United Kingdom. The annual cost in the United States is around $250. In 2016 it was the 243rd most prescribed medication in the United States with more than 2 million prescriptions.