<unk>  sold under the brandname Intropin among others, is a medication most commonly used in the treatment of very low blood pressure, a slow heart rate that is causing symptoms, and, if epinephrine is not available, cardiac arrest. In newborn babies it continues to be the preferred treatment for very low blood pressure. In children epinephrine or norepinephrine is generally preferred while in adults norepinephrine is generally preferred for very low blood pressure. It is given intravenously or intraosseously as a continuous infusion. Effects typically begin within five minutes. Doses are then increased to effect. Common side effects include worsening kidney function, an irregular heartbeat, chest pain, vomiting, headache, or anxiety. If it enters into the soft tissue around the vein local tissue death may occur. The medication phentolamine can be given to try to decrease this risk. It is unclear if<unk> is safe to use during pregnancy or breastfeeding. At low doses<unk> mainly triggers<unk> receptors and β1-adrenergic receptors while at high doses it works via α-adrenergic receptors.<unk> was first synthesized in a laboratory in 1910 by George Barger and James Ewens in England. It is on the World Health Organization's List of Essential Medicines. In human physiology<unk> is a neurotransmitter as well as a hormone.
Dopamine 
Octopamine
Norepinephrine
Norepinephrine 
Catecholamine
Synephrine
Beta-Endorphin
Prolactin-releasing peptide