All of the muscarinic antagonists are competitive antagonists for the binding of acetylcholine to the muscarinic receptor.
IPRATROPIUM is used in the treatment of chronic obstructive pulmonary disease
(COPD) to produce bronchodilation.
(COPD) to produce bronchodilation.
Muscarinic antagonists are used for urinary frequency, urgency, and urge incontinence caused by bladder (detrusor) overactivity.
The competitive neuromuscular blocking drugs are used to produce skeletal muscle relaxation.
Notice that most of the drug names contain the letters “-cur-”. This should make it easier to recognize the drugs in this group when you see them.
Botulinum toxin blocks the release of acetylcholine at all cholinergic synapses.
Norepinephrine activates both α and β receptors, but activates β1 receptors more than β2 receptors. Because of its relatively low affinity for β2 receptors, norepinephrine is not as useful in the treatment of bronchospasm as epinephrine. Why? Because the smooth muscle of the bronchioles are relaxed by activation of β2 receptors.The main effect of α1 stimulation (with an agonist such as phenylephrine) is vasoconstriction.
At low doses, DOPAMINE causes renal and coronary vasodilation. It also activates β1 receptors in the heart.
The indirect-acting sympathomimetic agents act by releasing previously stored norepinephrine.
AMPHETAMINE and its relatives, dexmethylphenidate and methylphenidate, are central nervous system stimulants used to treat attention deficit hyperactivity disorder in children.