Neuropharmacology – Cholinergic, Anticholinergic & Dopaminergic Drugs (NURS1059)

A comprehensive set of flashcards covering key concepts, drug names, mechanisms, therapeutic uses, adverse effects, antidotes, and nursing considerations for cholinergic, anticholinergic, and dopaminergic agents.

Into which two major parts is the Neuropharmacology unit divided?

Part 1 – Cholinergic, Anticholinergic, Dopaminergic agents; Part 2 – Anti-epileptics, CNS stimulants & depressants, Muscle relaxants

What neurotransmitter is responsible for impulse transmission in the PNS?

Acetylcholine (ACh)

Name the two main types of cholinergic receptors.

Nicotinic receptors and Muscarinic receptors

Where are nicotinic receptors found, and why are they called nicotinic?

Found in both SNS and PNS ganglia and neuromuscular junctions; called nicotinic because nicotine can stimulate them

Where are muscarinic receptors located?

On effector organs (smooth muscle, myocardium, glands) supplied by PNS fibres

What is the general mechanism of action of cholinergic (parasympathomimetic) drugs?

They stimulate or mimic ACh at cholinergic receptors, acting as agonists

Differentiate direct-acting and indirect-acting cholinergic drugs.

Direct-acting bind to and activate receptors; indirect-acting inhibit acetylcholinesterase, thereby increasing ACh levels

Why do most cholinergic drugs have limited CNS penetration?

They carry a positive charge and are lipid-insoluble, so they do not cross the blood-brain barrier easily

List five classic ‘SLUDGE’ signs of cholinergic overdose.

Salivation, Lacrimation, Urinary incontinence, Diarrhea, GI cramps, Emesis

What is the antidote for severe cholinergic toxicity?

Atropine (an anticholinergic agent)

Which direct-acting cholinergic drug is used to treat urinary retention?

Bethanechol (Duvoid, Urecholine)

Which topical direct-acting cholinergic is used for glaucoma?

Pilocarpine

Which short-acting AChE inhibitor is used to diagnose myasthenia gravis?

Edrophonium (Tensilon, Enlon)

Name the longer-acting AChE inhibitor commonly used to manage myasthenia gravis.

Pyridostigmine (Mestinon)

Which AChE inhibitor is an antidote for anticholinergic overdose or organic poisoning?

Physostigmine

Give three cholinesterase inhibitors used in Alzheimer’s disease.

Donepezil, Galantamine, Rivastigmine

What is the primary therapeutic goal of Alzheimer’s cholinesterase inhibitors?

Slow memory loss, preserve cognitive function, and improve daily activity performance

State two common GI adverse effects of cholinergic drugs.

Nausea and diarrhea (often with increased salivation)

Which cardiovascular adverse event is most associated with cholinergic therapy?

Bradycardia (and possible heart block)

Before giving a cholinergic drug, which vital sign trend is especially important to assess?

Heart rate and blood pressure (for bradycardia or hypotension)

How do anticholinergic (parasympatholytic) drugs work?

They competitively block ACh at muscarinic receptors, decreasing PNS activity and allowing SNS effects to dominate

List three therapeutic effects of anticholinergic agents.

Increased heart rate, bronchodilation with decreased secretions, reduced GI motility & salivation (others: mydriasis, urinary retention)

Which natural anticholinergic drug is used for bradycardia and as a pre-anesthetic?

Atropine

Which anticholinergic patch is commonly used for motion sickness?

Scopolamine

Name two inhaled anticholinergics indicated for COPD or asthma.

Ipratropium (Atrovent) and Tiotropium (Spiriva)

Which anticholinergic is prescribed for Parkinson’s disease or antipsychotic-induced EPS?

Benztropine (Cogentin)

Which bladder-selective anticholinergic treats overactive bladder?

Tolterodine (Detrol, Detrol LA)

Describe the classic anticholinergic toxidrome mnemonic.

“Mad as a hatter (confusion), Blind as a bat (mydriasis), Dry as a bone (dry mucous membranes), Red as a beet (flushed), Hot as a hare (anhidrosis)”

What is the antidote for life-threatening anticholinergic toxicity?

Physostigmine (a centrally acting AChE inhibitor)

Give two major contraindications for anticholinergic use.

Glaucoma and GI obstruction/atony (others: allergy, stenosing peptic ulcer, CV instability)

What cardiovascular adverse effect is common with anticholinergics?

Tachycardia or dysrhythmias

Explain the neurotransmitter imbalance in Parkinson’s disease.

Too little dopamine and too much acetylcholine in the motor pathways

State the two-pronged pharmacologic approach to Parkinson’s therapy.

Increase dopamine action (dopaminergic agents) and/or inhibit ACh action (anticholinergic agents)

Why is dopamine itself not administered to treat Parkinson’s?

It cannot cross the blood-brain barrier

What is Levodopa’s mechanism of action?

It is a dopamine precursor that crosses the blood-brain barrier and is converted to dopamine by dopa-decarboxylase

Why is Levodopa combined with Carbidopa in Sinemet?

Carbidopa inhibits peripheral breakdown of levodopa, allowing more to reach the brain and reducing side effects

Name one significant cardiovascular adverse event with Levodopa therapy.

Orthostatic hypotension (increases fall risk)

Which dopamine receptor agonist can delay the need for Levodopa?

Bromocriptine

What is Amantadine’s dual mechanism in Parkinson’s disease?

Releases stored dopamine and inhibits dopamine re-uptake; also has mild anticholinergic effects

Identify two COMT inhibitors used as Levodopa adjuncts.

Entacapone and Tolcapone

List two notable adverse effects of Amantadine.

Confusion/irritability and skin discoloration (also narrow-angle glaucoma risk, on-off phenomenon)

Name two anticholinergic agents used to control Parkinsonian EPS.

Benztropine and Trihexyphenidyl (others: Biperiden, Diphenhydramine)

How should Levodopa be timed in relation to meals?

Preferably on an empty stomach for best absorption

Why must Parkinson’s medications be given at the same times every day?

To maintain consistent plasma levels and minimize ‘wearing-off’ motor fluctuations

What advice should be given about position changes for patients on dopaminergic drugs?

Change positions slowly to reduce risk of orthostatic hypotension

During dopaminergic therapy, which motor changes should be promptly reported?

Onset of involuntary movements or worsening EPS