Q&A

What is the difference between direct acting and indirect acting cholinergic agonists?

What is the difference between direct acting and indirect acting cholinergic agonists?

Examples of direct-acting cholinergic agents include choline esters (acetylcholine, methacholine, carbachol, bethanechol) and alkaloids (muscarine, pilocarpine, cevimeline). Indirect-acting cholinergic agents increase the availability of acetylcholine at the cholinergic receptors.

What is the action and side effects of cholinergic receptor agonists?

In medicine, the use of cholinergic agonists is limited because of their propensity to cause adverse effects in any organ under the control of the parasympathetic nervous system; adverse effects include blurred vision, cramps and diarrhea, low blood pressure and decreased heart rate, nausea and vomiting, salivation and …

What is the effect of a cholinergic agent?

These drugs suppress all the actions of the parasympathetic system, which results in drying up of the secretions of the body (e.g., saliva, tears, sweat, bronchial secretions, and gastrointestinal secretions); relaxation of the smooth muscle in the intestine, bronchi, and urinary bladder; an increase in the heart rate; …

What are cholinergic agonists used for?

Drugs that bind to and activate cholinergic receptors. A stimulatory alkaloid found in tobacco products that is often used for the relief of nicotine withdrawal symptoms and as an aid to smoking cessation.

Is indirect-acting irreversible cholinergic drug?

Cholinomimetics can be classified as: Direct-acting (receptor agonists), acting on muscarinic and nicotinic, and Indirect-acting (cholinesterase inhibitors), which, in turn, can be reversible or irreversible. Direct-acting cholinomimetics are drugs that act directly by stimulating cholinergic receptors.

What are the side effects of cholinergic agonists?

Cholinergic agonists may cause the following side effects:

  • Bone marrow suppression.
  • Sore throat.
  • Blurred vision.
  • Increased sweating and salivation.
  • Increased urinary frequency.
  • Rash.
  • Fever.
  • Dry mouth.

What is the difference between cholinergic and anticholinergic drugs?

Cholinergic agents allow you to see due to the production of fluid that moisturizes the eyes and you can salivate because of the production of mucus. You can also urinate and defecate. Anticholinergic agents decrease all the activities mentioned above.

Is Ibuprofen a cholinergic agent?

They both contain a non-steroidal anti-inflammatory drug (NSAID), ibuprofen (IBU) and pyridostigmine (PO), a cholinesterase inhibitor that acts as a cholinergic up-regulator (CURE).

What are the indications for cholinergic drugs?

Cholinergic drugs stimulate the parasympathetic nervous system by copying the action of Ach. They are given for Alzheimer’s disease, glaucoma, paralytic ileus, urinary retention, and myasthenia gravis.

What is the muscarinic effect?

: of, relating to, resembling, producing, or mediating the parasympathetic effects (such as a slowed heart rate and increased activity of smooth muscle) produced by muscarine muscarinic receptors — compare nicotinic.

How does an indirect acting cholinergic agonist work?

Indirect-Acting Cholinergic Agonists: how it works Do not react directly with ACh receptor sites React chemically with acetylcholinesterase in the synaptic cleft to prevent it from breaking down Ach As a result, ACh released from the presynaptic nerve accumulates, stimulating the ACh receptors for a longer time than expected

How does short acting cholinergic agent edrophonium work?

Edrophonium is a short acting agent work for around 10 min hence used only for diagnosis. Acetylcholinesterase inhibitors increase acetylcholine levels neuromuscular junction thereby increase the binding and activation of nicotinic acetylcholine receptors improving muscle contraction and hence muscle strength.

How are indirect acting cholinomimetics related to ACH-ASE?

INDIRECT ACTING CHOLINOMIMETICS (CHOLINESTERASE INHIBITORS) These drugs inhibit acetylcholinesterase and bytyrylcholinesterase, leading to increased acetylcholine at cholinoreceptors. Quaternary alcohols (e.g. erdrophonium) bind electrostatically to ACh-ase.

How does neostigmine work as a cholinergic agent?

Acetylcholinesterase inhibitors increase acetylcholine levels neuromuscular junction thereby increase the binding and activation of nicotinic acetylcholine receptors improving muscle contraction and hence muscle strength. Neostigmine is more selective for nicotinic receptors hence indicated for myasthenia gravis.