Anticholinergics (Atropine)
High-yield Verified · Oct 2026Block acetylcholine at muscarinic receptors on glands, smooth muscle, the heart and the brain — a competitive block that more acetylcholine can overcome, which is why an acetylcholinesterase inhibitor that enters the brain, physostigmine, reverses antimuscarinic delirium.
Nursing view → administration, monitoring and patient teaching
Compare: Autonomic receptors compared — muscarinic, nicotinic, adrenergic and dopamine →
Drugs
Mechanism
Competitively block muscarinic acetylcholine receptors, inhibiting parasympathetic tone — increasing heart rate and AV conduction, dilating pupils, reducing secretions and GI/urinary smooth-muscle tone, and (CNS-penetrant agents) affecting the brain.
Competitive blockade, tissue by tissue
Antimuscarinics competitively block acetylcholine binding at muscarinic receptors on exocrine glands, cardiac muscle and smooth muscle, including smooth muscle that responds to acetylcholine without cholinergic innervation. They cause minimal blockade at nicotinic sites, and there are no muscarinic receptors at the neuromuscular junction — so these drugs do not paralyze skeletal muscle.
The effect follows the receptor. M2 receptors in the SA and AV nodal cells slow the heart, so blocking them raises the heart rate. M3 receptors on gastrointestinal, urinary, airway and vascular smooth muscle and on exocrine glands drive peristalsis, bladder contraction and salivary, gastric and bronchial secretion; blocking them slows the gut, relaxes the bladder, dries secretions and dilates the bronchi. M1, M4 and M5 receptors in the CNS explain the confusion and cognitive impairment. Blockade in the eye dilates the pupil and causes photophobia.
Sweat glands are the odd one out: they are driven by sympathetic nerves, yet through postganglionic muscarinic receptors — so an antimuscarinic stops sweating, and the patient overheats. Atropine’s first effect on the heart can be paradoxical: small doses slow the rate before the characteristic tachycardia develops as vagal control is paralyzed.
Same receptor, different tissue preferences
The drugs do not block every tissue equally. Atropine acts more potently and longer than scopolamine on the heart, intestine and bronchial muscle, but more weakly on the iris, ciliary body and certain secretory glands. Scopolamine is the stronger drug at the eye and glands, and in the brain it blocks cholinergic transmission from the vestibular nuclei to higher centers and from the reticular formation to the vomiting center — the basis of its use against motion sickness.
Oxybutynin has only about one-fifth of atropine’s anticholinergic activity on detrusor muscle in animal tests, but four to ten times its antispasmodic activity, and it has no blocking effect at the neuromuscular junction or autonomic ganglia; its antimuscarinic activity lies mainly in the R-isomer. Benztropine combines anticholinergic and antihistaminic effects, but only the anticholinergic effect is established as therapeutic in parkinsonism. Trihexyphenidyl’s mechanism is not completely understood: it appears to inhibit parasympathetic efferent impulses directly, and at higher doses it may directly inhibit cerebral motor centers, with research pointing to dopamine and M1 receptors.
Glycopyrrolate blocks the same peripheral receptors as atropine — glands, smooth and cardiac muscle, the SA and AV nodes — but its vagal-blocking effect lasts 2 to 3 hours and its antisialagogue effect up to 7 hours, longer than atropine’s.
Tertiary versus quaternary: who gets into the brain
CNS effects depend on whether the drug can cross lipid membranes. Atropine and scopolamine are highly non-polar tertiary amines that penetrate lipid barriers easily; scopolamine crosses the blood–brain barrier and the placenta. Glycopyrrolate carries a highly polar quaternary ammonium group and, unlike atropine, is completely ionized at physiological pH, which limits its passage across the blood–brain barrier — so CNS side effects are less frequent than with tertiary amines.
Brain entry also changes what the CNS effect is. In clinical doses atropine does not depress the CNS but may stimulate the medulla and higher cerebral centers, whereas scopolamine causes drowsiness. Trihexyphenidyl reaches high concentrations in the brain, helped by intralysosomal uptake, and oxybutynin has reported CNS effects (hallucinations, agitation, confusion, somnolence).
The same rule governs the reversal agents. Physostigmine crosses the blood–brain barrier and so can treat CNS signs of antimuscarinic overdose; neostigmine, a quaternary ammonium anticholinesterase, does not cross it and acts only on peripheral effects (acetylcholinesterase inhibition itself is covered on the cholinergic agonists page).
Mydriasis versus cycloplegia
Two muscarinic targets in the eye give two separate effects. Blocking the iris sphincter lets the sympathetically driven radial dilator muscle act unopposed, so the pupil widens (mydriasis). Blocking the ciliary muscle paralyzes accommodation (cycloplegia), which reduces near vision — the effect needed for an accurate refraction, because the patient can no longer influence the measurement.
The drops differ in how much of each they give. Tropicamide is short-acting: it works in 15 to 30 minutes and lasts about 3 to 8 hours, and its weaker strength produces mydriasis with only slight cycloplegia — useful for a fundus examination. Cyclopentolate produces both mydriasis and cycloplegia; it acts rapidly but more briefly than atropine, with maximal cycloplegia in 25 to 75 minutes and recovery of accommodation in 6 to 24 hours, though mydriasis can take several days to clear in some people. Heavily pigmented irides may need more doses.
Dilating the pupil can transiently raise intraocular pressure, so untreated narrow-angle glaucoma or anatomically narrow angles may close. Reversing the dilation is hard: pilocarpine gives conflicting, sometimes only partial responses, and the α-blocking drop dapiprazole, which relaxes the dilator muscle, has been removed from the market by the FDA for reasons unrelated to safety.
Comparing the drugs
Where each drug acts and whether it reaches the brain
| Drug | Main site of action | CNS entry and effect | Distinguishing point |
|---|---|---|---|
| Atropine | Heart, intestine and bronchial muscle (more potent there than scopolamine) | Enters; in clinical doses may stimulate the medulla rather than depress the CNS | Small doses can first slow the heart |
| Scopolamine | Iris, ciliary body and secretory glands (stronger there than atropine); vestibular pathways | Crosses the blood–brain barrier; causes drowsiness | Transdermal; continued absorption from skin after removal |
| Glycopyrrolate | Glands and vagal reflexes | Quaternary — limited passage; fewer CNS effects | Antisialagogue effect up to 7 h, longer than atropine’s |
| Oxybutynin | Bladder (detrusor) smooth muscle | CNS effects reported (hallucinations, agitation, confusion, somnolence) | Strong direct antispasmodic effect; active metabolite N-desethyloxybutynin |
| Benztropine | Used for parkinsonism and drug-induced extrapyramidal disorders | — | Also antihistaminic; anticholinergic activity about atropine’s in isolated ileum |
| Trihexyphenidyl | Parasympathetic efferents; at higher doses cerebral motor centers (dopamine and M1 implicated) | High brain concentration (intralysosomal uptake) | Euphoriant; misuse potential |
| Tropicamide | Iris sphincter and ciliary muscle (eye drop); the weaker strength mainly dilates | Rarely systemic — low muscarinic affinity and receptor occupancy in plasma | Mydriasis with little cycloplegia at the weaker strength |
| Cyclopentolate | Iris sphincter and ciliary muscle (eye drop) | CNS disturbances, especially in young children and with stronger solutions | Mydriasis plus cycloplegia; shorter than atropine |
All are competitive muscarinic antagonists; the columns show tissue preference, brain entry and one distinguishing feature.
— = not stated in the listed sources.
Pharmacokinetics and time course
| Drug | Route | Metabolism and elimination | Time course |
|---|---|---|---|
| Atropine | IV | Largely enzymatic hydrolysis in the liver; 13–50% unchanged in urine | Elimination half-life more than doubled under age 2 and over 65 |
| Scopolamine | Transdermal patch | Metabolized and conjugated; under 5% unchanged in urine | Detectable within 4 h, peak by about 24 h; half-life 9.5 h after removal |
| Glycopyrrolate | IV, IM; oral solution | Mostly unchanged in urine (and bile); elimination severely impaired in renal failure | IV half-life about 0.83 h; IV onset within 1 minute |
| Oxybutynin | Oral, transdermal | CYP3A4 (liver and gut wall); under 0.1% unchanged in urine | Oral bioavailability about 6%; IV half-life about 2 h |
| Benztropine | Oral | — | — |
| Trihexyphenidyl | Oral | Hydroxylation of the alicyclic groups | Onset 60 min, peak 2 h; half-life about 5–10 h (up to 33 h reported) |
| Tropicamide | Eye drop | — | Acts in 15–30 min; lasts about 3–8 h; full recovery may take 24 h |
| Cyclopentolate | Eye drop | — | Maximal cycloplegia in 25–75 min; accommodation recovers in 6–24 h |
— = not stated in the listed sources.
Pharmacokinetics
- Charge and the blood–brain barrier — glycopyrrolate, atropine, scopolamine
- Glycopyrrolate’s quaternary ammonium group is completely ionized at physiological pH and limits its passage across lipid membranes; atropine and scopolamine are non-polar tertiary amines that penetrate easily. CNS side effects are correspondingly less frequent with glycopyrrolate.
- First-pass metabolism to an active metabolite — oxybutynin
- Oxybutynin is metabolized mainly by CYP3A4 in the liver and gut wall. By mouth, first-pass metabolism leaves about 6% bioavailability and makes the active N-desethyloxybutynin dominate (metabolite-to-parent AUC 11.9:1 after a single oral dose). The transdermal system bypasses this first pass — skin has little CYP3A4 — and the ratio falls to 1.3:1.
- Hepatic hydrolysis and age — atropine
- Much of a dose is destroyed by enzymatic hydrolysis, particularly in the liver, and 13–50% is excreted unchanged. Atropine crosses the placenta, protein binding is about 44%, and organophosphate pesticides inhibit its metabolism. The elimination half-life is more than doubled in children under 2 and in adults over 65.
- Renal elimination — glycopyrrolate
- About 85% of a labeled IV dose is recovered in urine within 48 hours, and over 80% of an IM dose appears in urine and bile as unchanged drug. In uremic patients the mean elimination half-life was 46.8 minutes versus 18.6 minutes in controls, and 3-hour urine excretion fell from 50% to 0.7% — elimination is severely impaired in renal failure.
- Transdermal depot — scopolamine
- Behind the ear, plasma levels are detectable within 4 hours and peak by about 24 hours. Scopolamine bound in the skin keeps being absorbed after the system is removed, and levels then fall with a half-life of 9.5 hours. It neither induces nor inhibits the main CYP enzymes in vitro.
- Brain uptake — trihexyphenidyl
- Well absorbed by mouth (onset about 60 minutes, peak about 2 hours), it reaches high brain concentrations helped by intralysosomal uptake, is metabolized by hydroxylation, and has an elimination half-life of about 5–10 hours, with up to 33 hours reported.
- Eye drops reach the circulation — tropicamide, cyclopentolate
- Drops are absorbed systemically through the nasolacrimal drainage, so pressing on the lacrimal sac for 2–3 minutes after instillation is used to reduce systemic absorption. Tropicamide’s low muscarinic affinity and very low plasma receptor occupancy mean systemic effects are rare; cyclopentolate’s CNS reactions are more common in young children and with stronger solutions.
- CNS effects outlast cardiac effects
- In overdose, most ingested anticholinergics act within 2 hours; their CNS effects can last more than 8 hours while cardiovascular effects are generally much shorter, and some topical agents, such as hyoscine, can act for over 24 hours.
Uses & drug choice
- Symptomatic bradycardia; pre-op drying of secretions; organophosphate/cholinergic-crisis antidote (atropine)
- Oxybutynin for overactive bladder and urge incontinence
- Motion sickness / postoperative nausea (scopolamine); Parkinsonism & drug-induced EPS (benztropine)
- Glycopyrrolate injection to reduce secretions and block cardiac vagal reflexes in anesthesia, and to protect against the muscarinic effects of neostigmine or pyridostigmine when neuromuscular blockade is reversed; also an adjunct for peptic ulcer
- Glycopyrrolate oral solution (Cuvposa) for chronic severe drooling in children 3–16 years with neurologic conditions such as cerebral palsy; glycopyrrolate tablets as an adjunct for peptic ulcer symptoms
- Tropicamide and cyclopentolate eye drops to dilate the pupil (mydriasis) and paralyze accommodation (cycloplegia) for eye examinations
- Trihexyphenidyl as an adjunct for all forms of parkinsonism and for drug-induced extrapyramidal disorders
Adverse effects
- Dry mouth and dry skin
- M3 blockade in exocrine glands removes acetylcholine’s drive for salivary and other secretions.
- Blurred vision and photophobia
- Blocking the iris sphincter dilates the pupil (mydriasis, with photophobia), and blocking the ciliary muscle paralyzes accommodation, which reduces near vision.
- Tachycardia
- M2 blockade in the SA and AV nodal cells removes vagal slowing, so the heart rate rises. With atropine, small doses can first slow the rate before the tachycardia develops.
- Constipation, ileus and intestinal obstruction
- M3 blockade on gastrointestinal smooth muscle reduces peristalsis and smooth-muscle tone, so constipation can progress to ileus.
- Urinary retention, especially with prostatic enlargement
- M3 blockade reduces bladder (detrusor) contraction; oxybutynin’s relaxation of bladder smooth muscle is the therapeutic version of the same effect. With prostatic hypertrophy, atropine may lead to complete urinary retention.
- Decreased sweating, flushing, hyperthermia and heat stroke
- Sweat glands are sympathetic but use postganglionic muscarinic receptors, so antimuscarinics stop sweating and remove the main way to lose heat. Therapeutic atropine doses can also dilate skin vessels in the blush area (atropine flush) and cause atropine fever in infants and small children.
- Confusion, delirium and other CNS effects
- Blocking M1, M4 and M5 receptors in the CNS causes confusion and disorientation — mainly with drugs that cross the blood–brain barrier (tertiary amines), and less with quaternary glycopyrrolate.
- Acute angle-closure glaucoma
- Mydriasis can transiently raise intraocular pressure, and in untreated narrow-angle glaucoma or anatomically narrow angles the dilated iris can close the angle.
- CNS and cardiopulmonary reactions to eye drops in children
- Drops are absorbed systemically through the nasolacrimal drainage; young children and the elderly are the most susceptible to the systemic effects, which is why lacrimal-sac pressure after instillation is used.
Toxicity & antidote
The toxidrome is the tissue map taken to excess: red as a beet (flushing), dry as a bone (anhidrosis), blind as a bat (mydriasis), mad as a hatter (altered mental status), hot as a hare (fever), full as a flask (urinary retention), plus decreased bowel sounds and tachycardia. Delirium, hallucinations, agitation, picking at clothing and staccato speech are typical; seizures can occur. It can look like sympathomimetic toxicity, but the absence of sweating points to an anticholinergic cause. CNS effects can outlast cardiovascular effects by many hours.
Antimuscarinic block is competitive and surmountable: it can be overcome by raising acetylcholine at the receptor — for example with an anticholinesterase that stops acetylcholine’s enzymatic breakdown. Physostigmine is an acetylcholinesterase inhibitor active in both the central and peripheral nervous systems, so the extra acetylcholine outcompetes the antagonist in the brain as well as at the periphery and the delirium clears. Neostigmine, which does not cross the blood–brain barrier, can only treat peripheral effects. (How acetylcholinesterase inhibitors work is on the cholinergic agonists page.)
Supportive care is usually enough, and IV benzodiazepines are first-line for agitation. Physostigmine is reserved for severe cases with both peripheral and central signs that are refractory to benzodiazepines, and generally for pure anticholinergic poisoning: its own excess causes bradycardia, hypersalivation, vomiting and seizures, so atropine is kept at the bedside, and with tricyclic antidepressants cardiac arrest is possible, so the label allows it only under continuous ECG monitoring. Wide-complex dysrhythmias (as with diphenhydramine) are treated with IV sodium bicarbonate, and in trihexyphenidyl overdose phenothiazines are contraindicated because their antimuscarinic action can deepen the toxicity.
Interactions
Contraindications
- Angle-closure glaucoma with the scopolamine patch, or uncontrolled narrow-angle glaucoma with oxybutynin — Labeled contraindications — pupil dilation blocks aqueous outflow, raising intraocular pressure and risking acute angle-closure.
- Narrow-angle glaucoma with atropine or benztropine, or with tropicamide or cyclopentolate eye drops (cyclopentolate: untreated narrow-angle glaucoma or anatomically narrow angles) use caution — Pupil dilation can precipitate acute angle-closure — a warning for these drugs (atropine’s label lists no contraindications, and the eye drops list only hypersensitivity).
- Urinary or gastric retention with oxybutynin (oral oxybutynin also: other severely decreased GI motility conditions) — Labeled contraindications — relaxing bladder and GI smooth muscle worsens retention.
- Benztropine in children under 3 years — Labeled contraindication because of its atropine-like effects; older children need caution.
- Trihexyphenidyl in narrow-angle glaucoma — Labeled contraindication — blindness after long-term use has been reported; the label calls for a gonioscope evaluation before starting and close eye-pressure monitoring.
- Glycopyrrolate by mouth, or injected for peptic ulcer, with glaucoma, obstructive uropathy (e.g. prostatic hypertrophy), GI obstruction or paralytic ileus, severe ulcerative colitis or toxic megacolon, or myasthenia gravis — Labeled contraindications (the lists differ slightly by product) — these conditions put the patient at risk of anticholinergic toxicity; the oral-solution and injection labels also list unstable cardiovascular status in acute hemorrhage. For its anesthesia uses, the injection lists only hypersensitivity.
- Glycopyrrolate oral solution (Cuvposa) with solid oral potassium chloride — Labeled contraindication — glycopyrrolate slows GI transit, so potassium chloride tablets can be held up against the gut lining and injure it; the tablet label also advises against the combination.
- Benign prostatic hyperplasia, pyloric obstruction, or paralytic ileus (atropine, benztropine, and others) use caution — Relaxing bladder/GI smooth muscle can turn partial obstruction or retention into complete obstruction — a warning rather than a listed contraindication for these drugs (for oral glycopyrrolate they are labeled contraindications).
- Older adults (Beers list — caution); hot environments use caution — Elders are sensitive to confusion, falls, and retention; impaired sweating causes heat illness.
- Tachyarrhythmias / myasthenia gravis (except atropine for specific uses) use caution — They further increase heart rate and oppose the ACh needed at the neuromuscular junction (for oral glycopyrrolate, myasthenia gravis is a labeled contraindication).
High-yield
- Quats stay out — quaternary glycopyrrolate (and neostigmine) cross the blood–brain barrier poorly: mainly peripheral effects
- Tertiaries travel — tertiary atropine and scopolamine cross it: central effects too (physostigmine crosses it as well)
The same rule picks the reversal agent: neostigmine for peripheral effects only, physostigmine when the delirium is central.
- Cyclopentolate — mydriasis plus cycloplegia (ciliary muscle paralyzed): for refraction
- Tropicamide — short-acting; the weaker strength gives mydriasis with little cycloplegia: for a fundus view
Pupil size comes from the iris sphincter; focusing comes from the ciliary muscle.
Practice questions
Q1A 2-year-old has a dilated eye examination with cyclopentolate drops. Forty minutes later he is restless, ataxic and hallucinating, with a flushed face and a fast pulse.
Which step during instillation would most have reduced the risk of this reaction?
- A.Using the stronger solution so that fewer drops are needed
- B.Using atropine drops instead, since they wear off faster
- C.Instilling a second drop straight away so the pupil dilates faster
- D.Pressing over the nasolacrimal (lacrimal) sac for 2–3 minutes after each drop
- E.Following each drop with a drop of pilocarpine
Show answer
D. Pressing over the nasolacrimal (lacrimal) sac for 2–3 minutes after each drop — Drops that drain through the nasolacrimal system are absorbed systemically, and infants and young children are especially prone to cyclopentolate’s CNS effects (ataxia, restlessness, hallucinations). The label calls for pressure over the nasolacrimal sac for two to three minutes after instillation to minimize absorption, and for observing infants closely for at least 30 minutes. Pilocarpine, given afterward, gives conflicting and sometimes only partial reversal of the dilation. CNS disturbances are more likely with the stronger solutions, and to minimize absorption the label uses a single drop of the weakest solution per eye before the sac pressure; cyclopentolate also acts for a shorter time than atropine, not a longer one.
Q2An 80-year-old woman taking oxybutynin is brought in confused and agitated after also taking an over-the-counter sleep aid. Her skin is hot, dry and flushed, her pupils are dilated, her bladder is distended and her bowel sounds are quiet. She remains severely agitated despite IV benzodiazepines.
The drug chosen to reverse her delirium works because it:
- A.Is a quaternary amine that blocks nicotinic receptors
- B.Directly stimulates M1 receptors without crossing the blood–brain barrier
- C.Binds and inactivates the antimuscarinic drug in plasma
- D.Is an α2 agonist that lowers central sympathetic outflow
- E.Inhibits acetylcholinesterase in the brain, raising acetylcholine enough to overcome a competitive block
Show answer
E. Inhibits acetylcholinesterase in the brain, raising acetylcholine enough to overcome a competitive block — This is the antimuscarinic toxidrome; the absence of sweating separates it from sympathomimetic toxicity. Antimuscarinic block is competitive and surmountable — overcome by raising acetylcholine with an anticholinesterase. Physostigmine is an acetylcholinesterase inhibitor active in both the central and peripheral nervous systems; it is used in severe cases with central and peripheral signs that are refractory to benzodiazepines. A quaternary anticholinesterase such as neostigmine does not cross the blood–brain barrier and treats only peripheral effects.
Q3At the end of surgery, an anesthesiologist gives neostigmine to reverse a nondepolarizing neuromuscular blocker and gives glycopyrrolate in the same syringe rather than atropine.
Which property of glycopyrrolate most explains the choice?
- A.Its quaternary ammonium group limits passage across the blood–brain barrier, so CNS effects are fewer
- B.It blocks nicotinic receptors at the neuromuscular junction
- C.It is a selective M3 agonist on bronchial smooth muscle
- D.It is metabolized by plasma cholinesterase within minutes
- E.It inhibits acetylcholinesterase in the CNS
Show answer
A. Its quaternary ammonium group limits passage across the blood–brain barrier, so CNS effects are fewer — Glycopyrrolate blunts neostigmine’s muscarinic effects (bradycardia, secretions, bronchoconstriction) while neostigmine restores neuromuscular transmission; the two are given together because their onsets are similar. Its highly polar quaternary group limits passage across the blood–brain barrier, so CNS side effects are lower than with tertiary atropine. Antimuscarinics cause minimal nicotinic blockade, and glycopyrrolate is mostly eliminated unchanged by the kidney.
Q4A 25-year-old has cyclopentolate drops for a refraction. Afterwards her pupils are wide and she cannot read her phone held close to her face, though distant objects are clear.
Her difficulty reading is due mainly to blockade of muscarinic receptors on which structure?
- A.The iris dilator muscle
- B.The ciliary muscle
- C.The lacrimal gland
- D.The retinal photoreceptors
- E.The iris sphincter muscle
Show answer
B. The ciliary muscle — Blocking the ciliary muscle paralyzes accommodation (cycloplegia), which reduces near vision — the effect a refraction needs. Blocking the iris sphincter instead dilates the pupil (mydriasis), leaving the sympathetically driven dilator unopposed; that explains the wide pupils and light sensitivity, not the loss of near focus. Accommodation usually recovers within 6 to 24 hours after cyclopentolate.
Q5A 70-year-old man with overactive bladder is switched from oral oxybutynin tablets to the oxybutynin transdermal system. His plasma level of the active metabolite falls relative to the parent drug.
Which explains the change?
- A.The skin converts oxybutynin to an inactive glucuronide
- B.The metabolite is excreted unchanged by the kidney after transdermal dosing
- C.Transdermal delivery bypasses first-pass CYP3A4 metabolism in the gut wall and liver
- D.The patch inhibits CYP2D6
- E.Transdermal oxybutynin is a quaternary amine
Show answer
C. Transdermal delivery bypasses first-pass CYP3A4 metabolism in the gut wall and liver — Oxybutynin is metabolized mainly by CYP3A4 in the liver and gut wall. After an oral dose, first-pass metabolism leaves about 6% bioavailability and a metabolite-to-parent (N-desethyloxybutynin) AUC ratio of 11.9:1. Transdermal administration bypasses first-pass gastrointestinal and hepatic metabolism — skin has little CYP3A4 — and the ratio falls to 1.3:1. Less than 0.1% of a dose is excreted unchanged.
Sources
- Anticholinergic Medications — antimuscarinic effects, toxidrome, contraindications — StatPearls (NCBI)
- Muscarinic Agonists / cholinergic pharmacology (atropine as antidote) — StatPearls (NCBI)
- Atropine — indications, paradoxical bradycardia, no absolute contraindications, overdose and physostigmine — StatPearls (NCBI)
- Anticholinergic Toxicity — toxidrome mnemonic, physostigmine — StatPearls (NCBI)
- Atropine Sulfate Injection — indications, small-dose slowing, glaucoma/urinary retention/pyloric warnings (FDA label) — FDA / DailyMed
- Oxybutynin Chloride Tablets — contraindications, heat prostration (FDA label) — FDA / DailyMed
- Transderm Scōp (scopolamine) — motion sickness/PONV, angle-closure glaucoma contraindication (FDA label) — FDA / DailyMed
- Benztropine Mesylate Tablets — parkinsonism/EPS, heat stroke, precautions (FDA label) — FDA / DailyMed
- Oxytrol (oxybutynin transdermal) — overactive bladder, contraindications (FDA label) — FDA / DailyMed
- Anticholium (physostigmine) — antidote for the anticholinergic syndrome (DailyMed label) — FDA / DailyMed
- Oxybutynin — adverse effects, Beers Criteria (as reported by StatPearls) — StatPearls (NCBI)
- Scopolamine — contraindications, overdose toxidrome — StatPearls (NCBI)
- Benztropine — myasthenia gravis caution, toxicity — StatPearls (NCBI)
- Organophosphate Toxicity — atropine and pralidoxime — StatPearls (NCBI)
- Autonomic Pharmacology — anticholinergic uses and adverse effects — StatPearls (NCBI)
- Strategies to Reduce Polypharmacy in Older Adults — anticholinergics, delirium and falls — StatPearls (NCBI)
- Sjogren Disease — dry-mouth relief (water, sugar-free gum, saliva substitutes) — StatPearls (NCBI)
- Physiology, Autonomic Nervous System — parasympathetic “rest and digest” — StatPearls (NCBI)
- Glycopyrrolate Injection (Hikma) — anesthesia and peptic-ulcer uses, quaternary amine with limited CNS entry, renal elimination, overdose (FDA label) — FDA / DailyMed
- Glycopyrrolate Tablets (Rising) — contraindications, GI motility, geriatric use, potassium chloride (FDA label) — FDA / DailyMed
- Cuvposa (glycopyrrolate oral solution) — chronic drooling in children, constipation, caregiver counseling (FDA label) — FDA / DailyMed
- Glyrx-PF (glycopyrrolate injection) — indications, contraindications (FDA label) — FDA / DailyMed
- Mydriacyl (tropicamide) — mydriasis and cycloplegia, pediatric CNS effects, lacrimal-sac pressure (FDA label) — FDA / DailyMed
- Cyclogyl (cyclopentolate) — mydriasis and cycloplegia, infant observation and feeding, CNS reactions (FDA label) — FDA / DailyMed
- Trihexyphenidyl Hydrochloride Oral Solution (Chartwell) — parkinsonism and EPS, narrow-angle glaucoma contraindication, withdrawal and NMS, heat (FDA label) — FDA / DailyMed
- Muscarinic Antagonists — M2/M3/CNS receptor sites, glycopyrrolate with neostigmine, physostigmine antidote — StatPearls (NCBI)
- Cholinergic Medications — physostigmine CNS effects, sympathetic muscarinic sweat glands — StatPearls (NCBI)
- Trihexyphenidyl — mechanism, brain uptake, pharmacokinetics, overdose — StatPearls (NCBI)
- Tropicamide — dilator vs sphincter, cycloplegia, systemic absorption, reversal — StatPearls (NCBI)
By LearnDrugs
Educational summary for medical students. Always verify against current prescribing information and guidelines. Not medical advice.