Orciprenaline, also known as metaproterenol, is a bronchodilator used in the treatment of asthma. Orciprenaline is a moderately selective β2 adrenergic receptor agonist that stimulates receptors of the smooth muscle in the lungs, uterus, and vasculature supplying skeletal muscle, with minimal or no effect on α adrenergic receptors. The pharmacologic effects of β adrenergic agonist drugs, such as orciprenaline, are at least in part attributable to stimulation through β adrenergic receptors of intracellular adenylyl cyclase, the enzyme which catalyzes the conversion of ATP to cAMP. Increased cAMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from many cells, especially from mast cells. Possible side effects
tremor
nervousness
dizziness
weakness
headache
nausea
tachycardiaRare side effects that could be life-threateningincreased difficulty breathing
rapid or increased heart rate
irregular heartbeat
chest pain or discomfort

Brand names
Alupent
Metaprel
Orcibest


== References ==
In cardiology, ventricular dyssynchrony is a difference in the timing, or lack of synchrony, of contractions in different ventricles in the heart. Large differences in timing of contractions can reduce cardiac efficiency and is correlated with heart failure. Types of dyssynchrony
Three chief presentations of dyssynchrony can occur:
Atrioventricular (AV) dyssynchrony occurs when there is an unfavorable difference in timing between atrial and ventricular contractions. Interventricular dyssynchrony occurs when there is a difference in timing between right ventricular (RV) and left ventricular (LV) Systole. Intraventricular dyssynchrony occurs when the timing in a sequence of activations and contractions of segments of the LV wall becomes abnormal. In all three types, changes in timing lead to changes in the dynamic behavior of the myocardial tissues, leading to mechanical dyssynchrony. All three presentations allow distinct and easily reproducible electrical signatures as illustrated by left and right bundle branch blocks, hemiblocks, etc. The concise measurement of the time and morphology of the QRS interval allows the interventional ability to manipulate this interval with biventricular pacemakers. It is important to distinguish ventricular dyssynchrony from ventricular dyssynergy. Dyssynergy refers to changes in relative strength of contractions, whereas dyssynchrony is a change in relative timing of contractions. Once again the terms inotropy and chronotropy apply to the pathology under examination. Biventricular pacing strongly favors chronotropy over inotropy. Diagnosis
Echocardiography and tissue Doppler echocardiography are both needed to fully diagnose the different types of ventricular dyssynchrony. Treatment
Recent studies suggest that cardiac resynchronization therapy can reduce the incidence of ventricular dyssynchrony and thus increase cardiac efficiency.