Ibopamine is a
sympathomimetic
Sympathomimetic drugs (also known as adrenergic drugs and adrenergic amines) are stimulant compounds which mimic the effects of endogenous agonists of the sympathetic nervous system. Examples of sympathomimetic effects include increases in hea ...
drug, designed as a
prodrug
A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the drug ...
of
epinine (deoxyepinephrine or ''N''-methyldopamine), used in
ophthalmology
Ophthalmology ( ) is a surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders.
An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a medic ...
.
It induces
mydriasis
Mydriasis is the dilation of the pupil, usually having a non-physiological cause, or sometimes a physiological pupillary response. Non-physiological causes of mydriasis include disease, trauma, or the use of certain types of drugs.
Normally, as ...
.
It also has been investigated for use in the treatment of
congestive heart failure
Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, a ...
.
It acts on
D1 and
α-adrenergic receptor
The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...
s as an
agonist
An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...
.
Ibopamine was first prepared by Casagrande and co-workers.
Instilled at 2% concentration, ibopamine exhibits several functions at ocular level such as pre- and post-operative mydriatic activity, D1 dopaminergic activity, etc.
Pharmacokinetics
Due to the esterases existing in the aqueous humour and ocular tissues, ibopamine can be rapidly hydrolysed to epinine which is the active molecule responsible for the mydriatic effect. The epinine, an analogue of dopamine, can stimulate dopamine receptors and to a lesser degree adrenergic receptors. Thus it is believed that epinine is the pharmacologically active moiety. It has been shown that the half-life of ibopamine is short to about 2 minutes in the aqueous humour owing to the fast hydrolysis. So ibopamine can not be found in the aqueous humor after instillation.
Pharmacodynamics
After being hydrolysed to epinine, ibopamine is able to stimulate the alpha-adrenergic and D1 dopaminergic receptors, thereby exhibiting mydriatic effects. In some randomized clinical trials, the D1 dopaminergic activity of ibopamine led to an increased production of aqueous humour and intraocular pressure (IOP) in primary open-angle glaucoma (POAG) patients.
Toxicology
At systemic and local levels, ibopamine has been proved to be of low toxicity. It is well tolerated since no obvious changes to the haematological and behavioural parameters have been observed after administration. Ibopamine eye drop at 2% concentration, containing 1 mg of the compound, did not show any significant systemic side-effects and tachyphylaxis phenomena whereas the oral dosage is higher than 400 mg per day.
Clinical Use
A fast and short-lasting mydriasis can be induced by ibopamine without systemic side-effects.
See also
*
Epinine
References
{{Dopamine receptor modulators
Alpha-1 adrenergic receptor agonists
Alpha-2 adrenergic receptor agonists
Beta-adrenergic agonists
D1-receptor agonists
D2-receptor agonists
Dopamine agonists
Isobutyrate esters
Phenethylamines
Prodrugs