The word Autacoids comes from the Greek “Autos” (self) and “Acos” (drug) and the general meaning is self-remedy. They are naturally occurring substances which do not normally circulate and are localized in tissues. Their sites of action are thus restricted to the synthesis area. They have diverse physiological and pharmacological activities with a short duration of action which primarily involve responses to injury. Of general importance are effects on smooth muscle contraction. With respect to vascular smooth muscle, there are both vasoconstrictor and vasodilator autacoids. Vasodilator autacoids can be released during periods of exercise. Their main effect is seen in the skin, allowing for heat loss.

Autacoids are a chemically diverse group of substances which are released in response to various types of stimulation. An imbalance in their synthesis, release or in the transduction system contributes significantly to pathological conditions such as inflammation, allergy, hypersensitivity and ischaemia.

The autacoids comprise histamine, serotonin, angiotensin, neurotensin, NO (nitric oxide), kinins, platelet-activating factor, endothelins and the four families of traditional eicosanoids – the leukotrienes and three types of prostanoids i.e. prostaglandins, prostacyclins, and thromboxanes. Several other natural occurring molecules are sometimes called eicosanoid, including the hepoxilins, resolvins, isofurans, isoprostanes, lipoxins, epoxyeicosatrienoic acids (EETs) and some endocannabinoids. However, not all the substances which can be categorized as autacoids have a direct bearing on our pharmacotherapeutic armamentarium.