Dichloroisoprenaline (DCI), also known as dichloroisoproterenol, was the first
beta blocker
Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack ( secondary prevention). They are ...
ever to be developed. It is non-selective for the
β1-adrenergic and
β2-adrenergic receptors. DCI has low
potency
Potency may refer to:
* Potency (pharmacology), a measure of the activity of a drug in a biological system
* Virility
* Cell potency, a measure of the differentiation potential of stem cells
* In homeopathic dilutions, potency is a measure of how ...
and acts as a
partial agonist
In pharmacology, partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist. They may also be considered ligands which display both agonistic and antagonis ...
/
antagonist
An antagonist is a character in a story who is presented as the chief foe of the protagonist.
Etymology
The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, ri ...
at these
receptor
Receptor may refer to:
*Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse
*Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a n ...
s.
Although DCI was of no clinical value itself, further developments from DCI eventually led to the development of the clinical candidate
pronethalol (withdrawn due to
carcinogenicity) and subsequently
propranolol
Propranolol, sold under the brand name Inderal among others, is a medication of the beta blocker class. It is used to treat high blood pressure, a number of types of irregular heart rate, thyrotoxicosis, capillary hemangiomas, performance an ...
(the first clinically successful beta blocker).
Dichloroisoprenaline is a racemic mixture of enantiomers.
References
Beta blockers
Chloroarenes
Phenylethanolamines
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