View source for Muscarinic antagonist

{{short description|Drug that binds to but does not activate muscarinic cholinergic receptors}}{{Multiple issues|Needs more citations. Includes a large table which needs to be turned into prose or removed.|collapsed=yes}}{{Infobox drug class
| Name = Muscarinic acetylcholine receptor antagonist
| Image = L-Scopolamin.svg
| ImageClass = skin-invert-image
| Alt = Scopolamine
| Synonyms = Muscarinic acetylcholine receptor antagonist; Antimuscarinic; Anti-muscarinic; mACh antagonist; mAChR antagonist; Muscarinic antagonist; Antimuscarinic agent; Antimuscarinic drug; Antimuscarinic medication
| Use = [[Allergy|Allergies]], [[asthma]], [[atrial fibrillation]] with [[bradycardia]],<ref name="medpagetoday.com">{{Cite web|url=https://www.medpagetoday.com/cardiology/arrhythmias/72859|title=Hyoscyamine Subs for Pacemaker in Afib with Bradycardia|date=May 14, 2018|website=www.medpagetoday.com}}</ref> [[motion sickness]], [[Parkinson's disease]], etc.
| Caption = [[Skeletal formula]] of [[Hyoscine hydrobromide|scopolamine]], a nonselective antagonist of the muscarinic receptors
| Biological_target = [[Muscarinic acetylcholine receptor]]s
| ATC_prefix = V
| MeshID = D018727
}}
A '''muscarinic acetylcholine receptor antagonist''', also simply known as a '''muscarinic antagonist''' or as an '''antimuscarinic agent''', is a type of [[anticholinergic]] [[drug]] that blocks the activity of the [[muscarinic acetylcholine receptor]]s (mAChRs). The muscarinic receptors are proteins involved in the transmission of signals through certain parts of the nervous system, and muscarinic receptor antagonists work to prevent this transmission from occurring. Notably, muscarinic antagonists reduce the activation of the [[parasympathetic nervous system]]. The normal function of the parasympathetic system is often summarised as "rest-and-digest", and includes slowing of the heart, an increased rate of digestion, [[Bronchoconstriction|narrowing of the airways]], promotion of urination, and sexual arousal. Muscarinic antagonists counter this parasympathetic "rest-and-digest" response, and also work elsewhere in both the [[Central nervous system|central]] and [[peripheral nervous system]]s.
Drugs with muscarinic antagonist activity are widely used in medicine, in the treatment of [[Bradycardia|low heart rate]], [[overactive bladder]], respiratory problems such as [[asthma]] and [[Chronic obstructive pulmonary disease|chronic obstructive pulmonary disease (COPD)]], and neurological problems such as [[Parkinson's disease]] and [[Alzheimer's disease]]. A number of other drugs, such as [[antipsychotic]]s and the [[Tricyclic antidepressant|tricyclic family of antidepressants]], have incidental muscarinic antagonist activity which can cause unwanted side effects such as [[Urinary retention|difficulty urinating]], dry mouth and skin, and [[constipation]].
[[Acetylcholine]] (often abbreviated '''ACh''') is a neurotransmitter whose receptors are proteins found in [[synapse]]s and other cell membranes. Besides responding to their primary neurochemical, neurotransmitter receptors can be sensitive to a variety of other molecules. Acetylcholine receptors are classified into two groups based on this:
* muscarinic, which respond to [[muscarine]]
* nicotinic, which respond to [[nicotine]]
Most muscarinic receptor antagonists are synthetic chemicals; however, the two most commonly used anticholinergics, [[Hyoscine hydrobromide|scopolamine]] and [[atropine]], are [[Atropa belladonna|belladonna alkaloids]], and are naturally extracted from plants such as ''[[Atropa belladonna]]'', the deadly nightshade. The name "belladonna", Italian for "beautiful lady", is thought to derive from one of the antimuscarinic effects of these alkaloids: they were used by women for cosmetic purposes, to promote dilation of the [[pupil]]s.<ref>{{Cite web|title=Belladonna: MedlinePlus Supplements|url=https://medlineplus.gov/druginfo/natural/531.html|access-date=2020-08-13|website=medlineplus.gov|language=en}}</ref>
Muscarinic antagonist effects and [[muscarinic agonist]] effects counterbalance each other for [[homeostasis]].
Certain muscarinic antagonists can be classified into either long-acting muscarinic receptor antagonists ('''LAMA'''s) or short-acting muscarinic receptor antagonists ('''SAMA'''s), depending on when maximum effect occurs and for how long the effect persists.<ref>{{Cite book|last=Ritter|first=James|url=https://www.worldcat.org/oclc/1081403059|title=Rang and Dale's pharmacology|date=2020|others=R. J. Flower, Graeme Henderson, Yoon Kong Loke, David J. MacEwan, H. P. Rang|isbn=978-0-7020-8060-9|edition=9th|location=Edinburgh|pages=377|oclc=1081403059}}</ref>
{{TOC limit|3}}
==Effects==
{{More citations needed|section|date=March 2024}}
[[Hyoscine hydrobromide|Scopolamine]] and [[atropine]] have similar effects on the [[peripheral nervous system]]. However, scopolamine has greater effects on the [[central nervous system]] (CNS) than atropine due to its ability to cross the [[blood–brain barrier]].<ref>{{Cite journal |doi = 10.1177/1756283X16670076|pmid = 28286563|pmc = 5330606|title = Antispasmodic drugs in colonoscopy: A review of their pharmacology, safety and efficacy in improving polyp detection and related outcomes|journal = Therapeutic Advances in Gastroenterology|volume = 10|issue = 1|pages = 101–113|year = 2017|last1 = Sanagapalli|first1 = Santosh|last2 = Agnihotri|first2 = Kriti|last3 = Leong|first3 = Rupert|last4 = Corte|first4 = Crispin John}}</ref> At higher-than-therapeutic doses, atropine and scopolamine cause CNS depression characterized by amnesia, fatigue, and reduction in [[Rapid eye movement (sleep)|rapid eye movement sleep]]. Scopolamine (Hyoscine) has [[anti-emetic]] activity and is, therefore, used to treat [[motion sickness]].
Antimuscarinics are also used as anti-parkinsonian drugs. In [[Parkinson's disease|parkinsonism]], there is imbalance between levels of [[acetylcholine]] and [[dopamine]] in the brain, involving both increased levels of acetylcholine and degeneration of [[dopaminergic]] pathways ([[nigrostriatal pathway]]). Thus, in parkinsonism there is decreased level of dopaminergic activity. One method of balancing the neurotransmitters is through blocking central cholinergic activity using muscarinic receptor antagonists.
Atropine acts on the [[M2 receptor]]s of the heart and antagonizes the activity of acetylcholine. It causes [[tachycardia]] by blocking vagal effects on the [[sinoatrial node]]. Acetylcholine hyperpolarizes the sinoatrial node; this is overcome by MRAs, and thus they increase the heart rate. If atropine is given by intramuscular or subcutaneous injection, it causes initial [[bradycardia]]. This is because when administered intramuscularly or subcutaneously atropine acts on presynaptic [[M1 receptor]]s ([[autoreceptor]]s). Uptake of acetylcholine in [[axoplasm]] is prevented and the presynaptic nerve releases more acetylcholine into the [[Chemical synapse|synapse]], which initially causes bradycardia.
In the [[atrioventricular node]], the [[resting potential]] is lowered, which facilitates conduction. This is seen as a shortened PR-interval on an [[electrocardiogram]]. It{{clarify|date=June 2015}} has an opposite effect on [[blood pressure]]. Tachycardia and stimulation of the [[vasomotor center]] causes an increase in blood pressure. But, due to feedback regulation of the vasomotor center, there is a fall in blood pressure due to [[vasodilation]].
Important<ref name=Rang147>{{cite book |author=Rang, H. P. |title=Pharmacology |publisher=Churchill Livingstone |location=Edinburgh |year=2003 |isbn=0-443-07145-4 }} Page 147</ref> muscarinic antagonists include [[atropine]], [[hyoscyamine]], [[hyoscine butylbromide]] and [[hyoscine hydrobromide|hydrobromide]], [[ipratropium]], [[tropicamide]], [[cyclopentolate]], [[pirenzepine]] and [[scopalamine]].
Muscarinic antagonists such as [[ipratropium bromide]] can also be effective in treating [[asthma]], since [[acetylcholine]] is known to cause [[smooth muscle]] contraction, especially in the [[bronchi]].
{{see|Cholinergic crisis#Treatment}}
==Comparison table==
{{Prose|date=March 2024|section}}
===Overview===
{|class="wikitable" style="font-size:small;"
!Substance
!Selectivity
!Clinical use
!Adverse effects
!Notes
!Trade names
|-
| [[Atropine]] (D/L-[[Hyoscyamine]])
|{{abbr|NS|Non-selective antagonism}}
|
* During [[anesthesia]]<ref name="Rang147" /><ref name="Mirakhur">{{cite journal | last=Mirakhur | first=RK | title=Preanaesthetic medication: a survey of current usage | journal=Journal of the Royal Society of Medicine | volume=84 | issue=8 | pages=481–483 |date=August 1991 | pmid=1886116 | pmc=1293378 | doi=10.1177/014107689108400811 }}</ref>
* Antidote to [[anticholinesterase poisoning]]<ref name="Rang147" />
* [[Atrial fibrillation]] with [[bradycardia]]<ref name="medpagetoday.com"/><ref name="Rang147" />
* [[Antispasmodic]] in gastrointestinal [[hypermotility]]<ref name="Rang147" />
|
* [[urinary retention|{{abbr|UR|Urinary retention}}]]<ref name="Rang147" />
* [[xerostomia]]<ref name="Rang147" />
* [[blurred vision]]<ref name="Rang147" />
|{{abbr|CD|Central nervous system depression}}<ref name="Rang147" />
|Symax, HyoMax, Anaspaz, Egazil, Buwecon, Cystospaz, Levsin, Levbid, Levsinex, Donnamar, NuLev, Spacol T/S and Neoquess
|-
| [[Atropine methonitrate]]
|{{abbr|NS|Non-selective antagonism}}
|
* [[antispasmodic]] in gastrointestinal [[hypermotility]]<ref name="Rang147" />
|
| Blocks transmission in [[ganglia]].<ref name="Rang147" /> Lacks CNS effects<ref name="Rang&Dale6th10-5">Table 10-5 in: {{cite book|title=Rang & Dale's pharmacology|author1=Rod Flower|author2=Humphrey P. Rang|author3=Maureen M. Dale|author4=Ritter, James M.|publisher=Churchill Livingstone|year=2007|isbn=978-0-443-06911-6|location=Edinburgh}}</ref>
|
|-
| [[Aclidinium bromide]]
|Selective{{Clarify|reason=What receptor is aclidinium selective for?|date=June 2019}}
|
* Bronchospasm
* COPD
|
| Long acting antagonist
| Tudorza
|-
| [[Benzatropine|Benztropine]]
|[[M1 receptor|M1]]-selective
|
* [[Parkinson's disease|{{abbr|PD|Parkinson's disease}}]]
* [[extrapyramidal symptoms|{{abbr|EPS|Extrapyramidal symptoms}}]] caused by typical and atypical [[antipsychotics]]
|
|Reduces the effects of the relative central cholinergic excess that occurs as a result of dopamine deficiency.
| Cogentin
|-
| [[Cyclopentolate]]
|{{abbr|NS|Non-selective antagonism}}
|
* produce [[mydriasis]] and [[cycloplegia]] in diagnostics<ref name="Rang147" />
|
* may cause [[ocular hypertension]]<ref name="Rang147" />
| Short acting, {{abbr|CD|Central nervous system depression}}<ref name="Rang147" />
|
|-
| [[Diphenhydramine]]
|{{abbr|NS|Non-selective antagonism}}
|
* for [[extrapyramidal symptoms|{{abbr|EPS|Extrapyramidal symptoms}}]] from typical and atypical [[antipsychotic]] medications
* antihistamine
* sleep aid
* [[Parkinson's disease|{{abbr|PD|Parkinson's disease}}]]
* management of [[asthma]] symptoms
|
* sedation
* dry mouth
* constipation
* [[urinary retention|{{abbr|UR|Urinary retention}}]]
| Acts in the central nervous system, blood vessels and smooth muscle tissues
| [[Benadryl]], [[Nytol]]
|-
| [[Doxylamine]]
|{{abbr|NS|Non-selective antagonism}}
|
* antihistamine<ref>{{cite web|url=http://www.drugbank.ca/drugs/DB00366|title=Doxylamine|website=www.drugbank.ca|access-date=21 March 2018}}</ref>
* antiemetic
* sleep aid
|
* dizziness
* dry mouth
|
| Unisom
|-
| [[Dimenhydrinate]]
|
|
* [[motion sickness]]
|
| Combination of diphenhydramine with a methylxanthine salt
| Dramamine, Gravol
|-
| [[Dicyclomine]]
|
|
* [[Irritable bowel syndrome|IBS]]
|
|
| Bentyl
|-
|[[Darifenacin]]
|Selective for [[M3 receptor|M3]]<ref name="Rang&Dale6th10-5" />
|Urinary incontinence <ref name="Rang&Dale6th10-5" />
|Few side effects<ref name="Rang&Dale6th10-5" />
|
|Enablex
|-
| [[Flavoxate]]
|
|
* [[Urinary bladder]] [[antispasmodic]]
|
|
| Urispas
|-
| [[Glycopyrronium bromide|Glycopyrrolate]] (Glycopyrronium bromide)
|{{abbr|NS|Non-selective antagonism}}
|
* Prior to anesthesia to reduce [[saliva]]ry, [[tracheobronchial]], and [[Pharynx|pharyngeal]] secretions
* In combination with [[neostigmine]] to prevent muscarinic effects such as [[bradycardia]]
* [[Sialorrhea]]
* [[Hyperhidrosis]]
* [[COPD]]
|
* Dry mouth
* [[urinary retention|{{abbr|UR|Urinary retention}}]]
* [[Headache]]
* [[Vomiting]]
| Does not cross the [[blood–brain barrier]] and has few to no central effects.<ref name="chabicovsky">{{cite journal |last1=Chabicovsky |first1=Monika |last2=Winkler |first2=Swantje |last3=Soeberdt |first3=Michael |last4=Kilic |first4=Ana |last5=Masur |first5=Clarissa |last6=Abels |first6=Christoph |title=Pharmacology, toxicology and clinical safety of glycopyrrolate |journal=Toxicology and Applied Pharmacology |date=1 May 2019 |volume=370 |pages=154–169 |doi=10.1016/j.taap.2019.03.016 |pmid=30905688 |s2cid=85498396 |url=https://pubmed.ncbi.nlm.nih.gov/30905688/ |issn=1096-0333}}</ref>
| Robinul, Cuvposa, Seebri
|-
| [[Hydroxyzine]]
|
|
|
|Very mild/negligible action
| Vistaril, Atarax
|-
| [[Ipratropium]] bromide
|{{abbr|NS|Non-selective antagonism}}
|[[Asthma]] and [[bronchitis]]<ref name="Rang147" />
|
* Bronchial vasodilation
| Lacks [[mucociliary excretion]] inhibition.<ref name="Rang147" />
| Atrovent and Apovent
|-
| [[Mebeverine]]
|
|
* [[Irritable bowel syndrome|IBS]] in its primary form (e.g., Abdominal Pain, Bloating, Constipation, and Diarrhea).
* Irritable bowel syndrome associated with organic lesions of the gastrointestinal tract. (e.g., diverticulosis & diverticulitis, etc.).
|
* skin rashes
|A muscolotropic spasmolytic with a strong and selective action on the smooth muscle spasm of the gastrointestinal tract, in particular of the colon.
| Colofac, Duspatal, Duspatalin
|-
| [[Oxybutynin]]
|M1/3/4 selective
|
* [[overactive bladder]]
* [[urge incontinence]]
|
|
| Ditropan
|-
| [[Pirenzepine]]
|[[M1 receptor|M1]]-selective<ref name="Rang147" />
|
* in [[peptic ulcer]] (not much anymore)<ref name="Rang147" />
| (fewer than non-selective ones)<ref name="Rang147" />
| Inhibits [[gastric secretion]]<ref name="Rang147" />
|
|-
|[[Procyclidine]]
|{{abbr|NS|Non-selective antagonism}}
|
* Drug-induced parkinsonism, akathisia and acute dystonia
* [[Parkinson's disease|{{abbr|PD|Parkinson's disease}}]]
* Idiopathic or secondary dystonia
|Overdose produces confusion, agitation and sleeplessness that can last up to or more than 24 hours. Pupils become dilated and unreactive to light. Tachycardia (fast heart beat), as well as auditory and visual hallucinations
|
|
|-
| [[Hyoscine hydrobromide|Scopolamine]] (L-Hyoscine)
|{{abbr|NS|Non-selective antagonism}}
|
* Same uses as atropine<ref name="Rang147" />
* [[Motion sickness]]<ref name="Rang147" />
|
* as atropine<ref name="Rang147" />
* [[sedation]]<ref name="Rang147" />
|{{abbr|CD|Central nervous system depression}}<ref name="Rang147" />
| Scopace, Transderm-Scop, Maldemar, Buscopan
|-
| [[Solifenacin]]
|
|
* [[overactive bladder]] (OAB)
* Urgency ([[urge incontinence]])
|
| Competitive antagonist
| Vesicare
|-
| [[Tropicamide]]
|{{abbr|NS|Non-selective antagonism}}
|
* produce [[mydriasis]] and [[cycloplegia]] in diagnostics<ref name="Rang147" />
|
* may cause [[ocular hypertension]]<ref name="Rang147" />
| Short acting, {{abbr|CD|Central nervous system depression}}<ref name="Rang147" />
|
|-
| [[Tiotropium]]
|
|
* [[Chronic obstructive pulmonary disease|COPD]]
|
|
| Spiriva
|-
|[[Trihexyphenidyl]]/[[Benzhexol]]
|M1 selective
|[[Parkinson's disease|{{abbr|PD|Parkinson's disease}}]]
|Drug at relative dose has 83% activity of atropine, thus has the same side-effects
|
|Artane
|-
| [[Tolterodine]]
|
|
* [[urge incontinence]]
|
|
| Detrusitol, Detrol
|}
The [[muscarinic acetylcholine receptor]] subtype [[binding selectivity|sectivities]] of a large number of antimuscarinic drugs have been reviewed.<ref name="LavradorCabralVeríssimo2023">{{cite journal | vauthors = Lavrador M, Cabral AC, Veríssimo MT, Fernandez-Llimos F, Figueiredo IV, Castel-Branco MM | title = A Universal Pharmacological-Based List of Drugs with Anticholinergic Activity | journal = Pharmaceutics | volume = 15 | issue = 1 | date = January 2023 | page = 230 | pmid = 36678858 | pmc = 9863833 | doi = 10.3390/pharmaceutics15010230 | doi-access = free | url = }}</ref>
===Binding affinities===
====Anticholinergics====
{| class="wikitable" style="font-size:small;"
|-
! Compound !! [[Muscarinic acetylcholine receptor M1|M<sub>1</sub>]] !! [[Muscarinic acetylcholine receptor M2|M<sub>2</sub>]] !! [[Muscarinic acetylcholine receptor M3|M<sub>3</sub>]] !! [[Muscarinic acetylcholine receptor M4|M<sub>4</sub>]] !! [[Muscarinic acetylcholine receptor M5|M<sub>5</sub>]] !! Species !! Ref
|-
| [[3-Quinuclidinyl benzilate]] || 0.035–0.044 || 0.027–0.030 || 0.080–0.088 || 0.034–0.037 || 0.043–0.065 || Human || <ref name="pmid1346637">{{cite journal | vauthors = Bolden C, Cusack B, Richelson E | title = Antagonism by antimuscarinic and neuroleptic compounds at the five cloned human muscarinic cholinergic receptors expressed in Chinese hamster ovary cells | journal = J. Pharmacol. Exp. Ther. | volume = 260 | issue = 2 | pages = 576–80 | year = 1992 | pmid = 1346637 }}</ref><ref name="pmid8100134" />
|-
| [[4-DAMP]] || 0.57–0.58 || 3.80–7.3 || 0.37–0.52 || 0.72–1.17 || 0.55–1.05 || Human || <ref name="pmid1994002" /><ref name="pmid10374898" />
|-
| [[AF-DX 250]] || 427 || 55.0 || 692 || 162 || 3020 || Human || <ref name="pmid1994002" />
|-
| [[AFDX-384|AF-DX 384]] || 30.9 || 6.03 || 66.1 || 10.0 || 537 || Human || <ref name="pmid1994002" />
|-
| [[AQ-RA 741]] || 28.8 || 4.27 || 63.1 || 6.46 || 832 || Human || <ref name="pmid1994002" />
|-
| [[Atropine]] || 0.21–0.50 || 0.76–1.5 || 0.15–1.1 || 0.13–0.6 || 0.21–1.7 || Human || <ref name="pmid1346637" /><ref name="pmid2704370">{{cite journal | vauthors = Buckley NJ, Bonner TI, Buckley CM, Brann MR | title = Antagonist binding properties of five cloned muscarinic receptors expressed in CHO-K1 cells | journal = Mol. Pharmacol. | volume = 35 | issue = 4 | pages = 469–76 | year = 1989 | pmid = 2704370 }}</ref><ref name="pmid10374898">{{cite journal | vauthors = Moriya H, Takagi Y, Nakanishi T, Hayashi M, Tani T, Hirotsu I | title = Affinity profiles of various muscarinic antagonists for cloned human muscarinic acetylcholine receptor (mAChR) subtypes and mAChRs in rat heart and submandibular gland | journal = Life Sci. | volume = 64 | issue = 25 | pages = 2351–8 | year = 1999 | pmid = 10374898 | doi = 10.1016/s0024-3205(99)00188-5}}</ref>
|-
| [[Benzatropine|Benzatropine (benztropine)]] || 0.231 || 1.4 || 1.1 || 1.1 || 2.8 || Human || <ref name="pmid1346637" />
|-
| [[Biperiden]] || 0.48 || 6.3 || 3.9 || 2.4 || 6.3 || Human || <ref name="pmid1346637" />
|-
| [[Darifenacin]] || 5.5–13 || 47–77 || 0.84–2.0 || 8.6–22 || 2.3–5.4 || Human || <ref name="pmid10374898" /><ref name="pmid11303071" />
|-
| [[Dicycloverine|Dicycloverine (dicyclomine)]] || 57 ([[IC50|IC<sub>50</sub>]]) || 415 (IC<sub>50</sub>) || 67 (IC<sub>50</sub>) || 97 (IC<sub>50</sub>) || 53 (IC<sub>50</sub>) || Human/rat || <ref name="pmid2704370" />
|-
| [[Glycopyrrolate]] || 0.37 || 1.38 || 1.31 || 0.41 || 1.30 || Human || <ref name="chabicovsky" />
|-
| [[Hexahydrodifenidol]] || 11 || 200 || 16 || 76 (IC<sub>50</sub>) || 83 || Human/rat || <ref name="pmid2704370" />
|-
| [[Hexahydrosiladifenidol]] || 44 || 249 || 10 || 298 (IC<sub>50</sub>) || 63 || Human/rat || <ref name="pmid2704370" />
|-
| [[Hexbutinol|(''R'')-Hexbutinol]] || 2.09 || 20.9 || 2.14 || 3.02 || 5.50 || Human || <ref name="pmid1994002" />
|-
| [[Hexocyclium]] || 2.3 || 23 || 1.4 || 5.5 || 3.7 || Human/rat || <ref name="pmid2704370" />
|-
| [[Himbacine]] || 107 || 10.0 || 93.3 || 11.0 || 490 || Human || <ref name="pmid1994002" />
|-
| [[Ipratropium]] || 0.49 || 1.5 || 0.51 || 0.66 || 1.7 || Human || <ref name="pmid11303071">{{cite journal | vauthors = Hirose H, Aoki I, Kimura T, Fujikawa T, Numazawa T, Sasaki K, Sato A, Hasegawa T, Nishikibe M, Mitsuya M, Ohtake N, Mase T, Noguchi K | title = Pharmacological properties of (2R)-N-[1-(6-aminopyridin-2-ylmethyl)piperidin-4-yl]-2-[(1R)-3,3-difluorocyclopentyl]-2-hydroxy-2-phenylacetamide: a novel mucarinic antagonist with M(2)-sparing antagonistic activity | journal = J. Pharmacol. Exp. Ther. | volume = 297 | issue = 2 | pages = 790–7 | year = 2001 | pmid = 11303071 }}</ref>
|-
| [[Methoctramine]] || 16–50 || 3.6–14.4 || 118–277 || 31.6–38.0 || 57–313 || Human || <ref name="pmid2704370" /><ref name="pmid1994002" /><ref name="pmid7805774" />
|-
| [[Methylscopolamine|''N''-Methylscopolamine]] || 0.054–0.079 || 0.083–0.251 || 0.052–0.099 || 0.026–0.097 || 0.106–0.125 || Human || <ref name="pmid1994002">{{cite journal | vauthors = Dörje F, Wess J, Lambrecht G, Tacke R, Mutschler E, Brann MR | title = Antagonist binding profiles of five cloned human muscarinic receptor subtypes | journal = J. Pharmacol. Exp. Ther. | volume = 256 | issue = 2 | pages = 727–33 | year = 1991 | pmid = 1994002 }}</ref>
|-
| [[Orphenadrine]] || 48 || 213 || 120 || 170 || 129 || Human || <ref name="pmid8100134" />
|-
| [[Otenzepad|Otenzepad (AF-DX 116)]] || 1300 || 186 || 838 || 1800 (IC<sub>50</sub>) || 2800 || Human/rat || <ref name="pmid2704370" />
|-
| [[Oxybutynin]] || 0.66 || 13 || 0.72 || 0.54 || 7.4 || Human || <ref name="pmid10374898" />
|-
| [[pFHHSiD]] || 22.4 || 132 || 15.5 || 31.6 || 93.3 || Human || <ref name="pmid1994002" />
|-
| [[Pirenzepine]] || 6.3–8 || 224–906 || 75–180 || 17–37 || 66–170 || Human || <ref name="pmid1346637" /><ref name="pmid2704370" /><ref name="pmid1994002" /><ref name="pmid10374898" />
|-
| [[Procyclidine]] || 4.6 || 25 || 12.4 || 7 || 24 || Human || <ref name="pmid1346637" />
|-
| [[Propiverine]] || 476 || 2970 || 420 || 536 || 109 || Human || <ref name="pmid10374898" />
|-
| [[Scopolamine|Scopolamine (hyoscine)]] || 1.1 || 2.0 || 0.44 || 0.8 || 2.07 || Human || <ref name="pmid1346637" />
|-
| [[Silahexacyclium]] || 2.0 || 35 || 1.2 || 3.2 || 2.0 || Human/rat || <ref name="pmid2704370" />
|-
| [[Timepidium]] || 34 || 7.7 || 31 || 18 || 11 || Human || <ref name="pmid10374898" />
|-
| [[Tiquizium]] || 4.1 || 4.0 || 2.8 || 3.6 || 8.2 || Human || <ref name="pmid10374898" />
|-
| [[Trihexyphenidyl]] || 1.6 || 7 || 6.4 || 2.6 || 15.9 || Human || <ref name="pmid1346637" />
|-
| [[Tripitamine|Tripitamine (tripitramine)]] || 1.58 || 0.27 || 38.25 || 6.41 || 33.87 || Human || <ref name="pmid7805774">{{cite journal | vauthors = Maggio R, Barbier P, Bolognesi ML, Minarini A, Tedeschi D, Melchiorre C | title = Binding profile of the selective muscarinic receptor antagonist tripitramine | journal = Eur. J. Pharmacol. | volume = 268 | issue = 3 | pages = 459–62 | year = 1994 | pmid = 7805774 | doi = 10.1016/0922-4106(94)90075-2}}</ref>
|-
| [[Zamifenacin]] || 55 || 153 || 10 || 68 || 34 || Human || <ref name="pmid10374898" />
|- class="sortbottom"
| colspan="8" | Values are K<sub>i</sub> (nM). The smaller the value, the more strongly the drug binds to the site.
|}
====Antihistamines====
{| class="wikitable" style="font-size:small;"
|-
! Compound !! [[Muscarinic acetylcholine receptor M1|M<sub>1</sub>]] !! [[Muscarinic acetylcholine receptor M2|M<sub>2</sub>]] !! [[Muscarinic acetylcholine receptor M3|M<sub>3</sub>]] !! [[Muscarinic acetylcholine receptor M4|M<sub>4</sub>]] !! [[Muscarinic acetylcholine receptor M5|M<sub>5</sub>]] !! Species !! Ref
|-
| [[Brompheniramine]] || 25700 || 32400 || 50100 || 67600 || 28800 || Human || <ref name="pmid10212017">{{cite journal | vauthors = Yasuda SU, Yasuda RP | title = Affinities of brompheniramine, chlorpheniramine, and terfenadine at the five human muscarinic cholinergic receptor subtypes | journal = Pharmacotherapy | volume = 19 | issue = 4 | pages = 447–51 | year = 1999 | pmid = 10212017 | doi = 10.1592/phco.19.6.447.31041| s2cid = 39502992 }}</ref>
|-
| [[Chlorphenamine|Chlorphenamine (chlorpheniramine)]] || 19000 || 17000 || 52500 || 77600 || 28200 || Human || <ref name="pmid10212017" />
|-
| [[Cyproheptadine]] || 12 || 7 || 12 || 8 || 11.8 || Human || <ref name="pmid8100134" />
|-
| [[Diphenhydramine]] || 80–100 || 120–490 || 84–229 || 53–112 || 30–260 || Human || <ref name="pmid1346637" /><ref name="pmid23357028">{{cite journal | vauthors = Krystal AD, Richelson E, Roth T | title = Review of the histamine system and the clinical effects of H1 antagonists: basis for a new model for understanding the effects of insomnia medications | journal = Sleep Med Rev | volume = 17 | issue = 4 | pages = 263–72 | year = 2013 | pmid = 23357028 | doi = 10.1016/j.smrv.2012.08.001 }}</ref>
|-
| [[Doxylamine]] || 490 || 2100 || 650 || 380 || 180 || Human || <ref name="pmid23357028" />
|-
| [[Mequitazine]] || 5.6 || 14 || 5.3 || 11.1 || 11.0 || Human || <ref name="pmid8100134" />
|-
| [[Terfenadine]] || 8710 || 8510 || 5250 || 30900 || 11200 || Human || <ref name="pmid10212017" />
|- class="sortbottom"
| colspan="8" | Values are K<sub>i</sub> (nM). The smaller the value, the more strongly the drug binds to the site.
|}
====Antidepressants====
{| class="wikitable" style="font-size:small;"
|-
! Compound !! [[Muscarinic acetylcholine receptor M1|M<sub>1</sub>]] !! [[Muscarinic acetylcholine receptor M2|M<sub>2</sub>]] !! [[Muscarinic acetylcholine receptor M3|M<sub>3</sub>]] !! [[Muscarinic acetylcholine receptor M4|M<sub>4</sub>]] !! [[Muscarinic acetylcholine receptor M5|M<sub>5</sub>]] !! Species !! Ref
|-
| [[Amitriptyline]] || 14.7 || 11.8 || 12.8 || 7.2 || 15.7 || Human || <ref name="pmid8100134">{{cite journal | vauthors = Stanton T, Bolden-Watson C, Cusack B, Richelson E | title = Antagonism of the five cloned human muscarinic cholinergic receptors expressed in CHO-K1 cells by antidepressants and antihistaminics | journal = Biochem. Pharmacol. | volume = 45 | issue = 11 | pages = 2352–4 | year = 1993 | pmid = 8100134 | doi = 10.1016/0006-2952(93)90211-e}}</ref>
|-
| [[Bupropion]] || >35,000 || >35,000 || >35,000 || >35,000 || >35,000 || Human || <ref name="pmid8100134" />
|-
| [[Citalopram]] || 1430 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12232544">{{cite journal | vauthors = Owens JM, Knight DL, Nemeroff CB | title = [Second generation SSRIS: human monoamine transporter binding profile of escitalopram and R-fluoxetine] | language = fr | journal = Encephale | volume = 28 | issue = 4 | pages = 350–5 | year = 2002 | pmid = 12232544 }}</ref>
|-
| [[Desipramine]] || 110 || 540 || 210 || 160 || 143 || Human || <ref name="pmid8100134" />
|-
| [[Desmethylcitalopram]] || >10000 || >10000 || >10000 || >10000 || >10000 || Human || <ref name="pmid17850785" />
|-
| [[Desmethyldesipramine]] || 404 || 927 || 317 || 629 || 121 || Human || <ref name="pmid17850785">{{cite journal | vauthors = Deupree JD, Montgomery MD, Bylund DB | title = Pharmacological properties of the active metabolites of the antidepressants desipramine and citalopram | journal = Eur. J. Pharmacol. | volume = 576 | issue = 1–3 | pages = 55–60 | year = 2007 | pmid = 17850785 | pmc = 2231336 | doi = 10.1016/j.ejphar.2007.08.017 }}</ref>
|-
| [[Desvenlafaxine]] || >10000 || >10000 || >10000 || >10000 || >10000 || Human || <ref name="pmid16675639">{{cite journal | vauthors = Deecher DC, Beyer CE, Johnston G, Bray J, Shah S, Abou-Gharbia M, Andree TH | title = Desvenlafaxine succinate: A new serotonin and norepinephrine reuptake inhibitor | journal = J. Pharmacol. Exp. Ther. | volume = 318 | issue = 2 | pages = 657–65 | year = 2006 | pmid = 16675639 | doi = 10.1124/jpet.106.103382 | s2cid = 15063064 }}</ref>
|-
| [[Dosulepin|Dosulepin (dothiepin)]] || 18 || 109 || 38 || 61 || 92 || Human || <ref name="pmid8100134" />
|-
| [[Doxepin]] || 18–38 || 160–230 || 25–52 || 20–82 || 5.6–75 || Human || <ref name="pmid23357028" /><ref name="pmid8100134" />
|-
| [[Escitalopram]] || 1242 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12232544" />
|-
| [[Etoperidone]] || >35000 || >35000 || >35000 || >35000 || >35000 || Human || <ref name="pmid8100134" />
|-
| [[Femoxetine]] || 92 || 150 || 220 || 470 || 400 || Human || <ref name="pmid8100134" />
|-
| [[Fluoxetine]] || 702–1030 || 2700 || 1000 || 2900 || 2700 || Human || <ref name="pmid8100134" /><ref name="pmid12232544" />
|-
| [[Fluvoxamine]] || 31200 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12232544" />
|-
| [[Imipramine]] || 42 || 88 || 60 || 112 || 83 || Human || <ref name="pmid8100134" />
|-
| [[Lofepramine]] || 67 || 330 || 130 || 340 || 460 || Human || <ref name="pmid8100134" />
|-
| [[Norfluoxetine]] || 1200 || 4600 || 760 || 2600 || 2200 || Human || <ref name="pmid8100134" />
|-
| [[Nortriptyline]] || 40 || 110 || 50 || 84 || 97 || Human || <ref name="pmid8100134" />
|-
| [[Paroxetine]] || 72–300 || 340 || 80 || 320 || 650 || Human || <ref name="pmid8100134" /><ref name="pmid12232544" />
|-
| [[Sertraline]] || 427–1300 || 2100 || 1300 || 1400 || 1900 || Human || <ref name="pmid8100134" /><ref name="pmid12232544" />
|-
| [[Tianeptine]] || >10000 || >10000 || >10000 || >10000 || >10000 || Human || <ref name="PDSP-Tianeptine">{{cite web | title = PDSP K<sub>i</sub> Database | work = Psychoactive Drug Screening Program (PDSP) | author1 = Roth, BL | author2 = Driscol, J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://kidbdev.med.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testDDRadio=testDDRadio&testLigandDD=tianeptine&testLigand=&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref>
|-
| [[Trazodone]] || >35,000 || >35,000 || >35,000 || >35,000 || >35,000 || Human || <ref name="pmid23357028" /><ref name="pmid8100134" />
|-
| [[Venlafaxine]] || >35000 || >35000 || >35000 || >35000 || >35000 || Human || <ref name="pmid8100134" />
|- class="sortbottom"
| colspan="8" | Values are K<sub>i</sub> (nM). The smaller the value, the more strongly the drug binds to the site.
|}
====Antipsychotics====
{| class="wikitable" style="font-size:small;"
|-
! Compound !! [[Muscarinic acetylcholine receptor M1|M<sub>1</sub>]] !! [[Muscarinic acetylcholine receptor M2|M<sub>2</sub>]] !! [[Muscarinic acetylcholine receptor M3|M<sub>3</sub>]] !! [[Muscarinic acetylcholine receptor M4|M<sub>4</sub>]] !! [[Muscarinic acetylcholine receptor M5|M<sub>5</sub>]] !! Species !! Ref
|-
| [[Amisulpride]] || >10,000 || >10,000 || >10,000 || >10,000 || >10,000 || Human || <ref name="pmid19337725">{{cite journal | vauthors = Abbas AI, Hedlund PB, Huang XP, Tran TB, Meltzer HY, Roth BL |author6-link=Bryan Roth | title = Amisulpride is a potent 5-HT7 antagonist: relevance for antidepressant actions in vivo | journal = Psychopharmacology | volume = 205 | issue = 1 | pages = 119–28 | year = 2009 | pmid = 19337725 | pmc = 2821721 | doi = 10.1007/s00213-009-1521-8 }}</ref>
|-
| [[Aripiprazole]] || 6780 || 3510 || 4680 || 1520 || 2330 || Human || <ref name="pmid12784105">{{cite journal | vauthors = Shapiro DA, Renock S, Arrington E, Chiodo LA, Liu LX, Sibley DR, Roth BL, Mailman R | title = Aripiprazole, a novel atypical antipsychotic drug with a unique and robust pharmacology | journal = Neuropsychopharmacology | volume = 28 | issue = 8 | pages = 1400–11 | year = 2003 | pmid = 12784105 | doi = 10.1038/sj.npp.1300203 | doi-access = free }}</ref>
|-
| [[Asenapine]] || >10000 || >10000 || >10000 || >10000 || {{abbr|ND|No data}} || Human || <ref name="pmid8822531" />
|-
| [[Bromperidol]] || 7600 || 1800 || 7140 || 1700 || 4800 || Human || <ref name="pmid1346637" />
|-
| [[Chlorprothixene]] || 11 || 28 || 22 || 18 || 25 || Human || <ref name="pmid1346637" />
|-
| [[Chlorpromazine]] || 25 || 150 || 67 || 40 || 42 || Human || <ref name="pmid1346637" />
|-
| [[Clozapine]] || 1.4–31 || 7–204 || 6–109 || 5–27 || 5–26 || Human || <ref name="pmid1346637" /><ref name="pmid8822531" /><ref name="pmid14642972">{{cite journal | vauthors = Bymaster FP, Felder CC, Tzavara E, Nomikos GG, Calligaro DO, Mckinzie DL | title = Muscarinic mechanisms of antipsychotic atypicality | journal = Prog. Neuropsychopharmacol. Biol. Psychiatry | volume = 27 | issue = 7 | pages = 1125–43 | year = 2003 | pmid = 14642972 | doi = 10.1016/j.pnpbp.2003.09.008 | s2cid = 28536368 }}</ref><ref name="pmid10708730">{{cite journal | vauthors = Bymaster FP, Falcone JF | title = Decreased binding affinity of olanzapine and clozapine for human muscarinic receptors in intact clonal cells in physiological medium | journal = Eur. J. Pharmacol. | volume = 390 | issue = 3 | pages = 245–8 | year = 2000 | pmid = 10708730 | doi = 10.1016/s0014-2999(00)00037-6}}</ref>
|-
| [[Cyamemazine|Cyamemazine (cyamepromazine)]] || 13 || 42 || 32 || 12 || 35 || Human || <ref name="pmid12527336">{{cite journal | vauthors = Hameg A, Bayle F, Nuss P, Dupuis P, Garay RP, Dib M | title = Affinity of cyamemazine, an anxiolytic antipsychotic drug, for human recombinant dopamine vs. serotonin receptor subtypes | journal = Biochem. Pharmacol. | volume = 65 | issue = 3 | pages = 435–40 | year = 2003 | pmid = 12527336 | doi = 10.1016/s0006-2952(02)01515-0}}</ref>
|-
| [[Desmethylclozapine|''N''-Desmethylclozapine]] || 67.6 || 414.5 || 95.7 || 169.9 || 35.4 || Human || <ref name="PDSP-Desmethylclozapine">{{cite web | title = PDSP K<sub>i</sub> Database | work = Psychoactive Drug Screening Program (PDSP) | author1 = Roth, BL | author2 = Driscol, J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://kidbdev.med.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testDDRadio=testDDRadio&testLigandDD=1973&testLigand=&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref>
|-
| [[Fluperlapine]] || 8.8 || 71 || 41 || 14 || 17 || Human || <ref name="pmid1346637" />
|-
| [[Fluphenazine]] || 1095 || 7163 || 1441 || 5321 || 357 || Human || <ref name="PDSP-Fluphenazine">{{cite web | title = PDSP K<sub>i</sub> Database | work = Psychoactive Drug Screening Program (PDSP) | author1 = Roth, BL | author2 = Driscol, J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://kidbdev.med.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testLigandDD=&testFreeRadio=testFreeRadio&testLigand=fluphenazine&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref>
|-
| [[Haloperidol]] || >10000 || >10000 || >10000 || >10000 || >10000 || Human || <ref name="pmid8822531" /><ref name="pmid14642972" />
|-
| [[Iloperidone]] || 4898 || 3311 || >10000 || 8318 || >10000 || Human || <ref name="pmid11750183">{{cite journal | vauthors = Kalkman HO, Subramanian N, Hoyer D | title = Extended radioligand binding profile of iloperidone: a broad spectrum dopamine/serotonin/norepinephrine receptor antagonist for the management of psychotic disorders | journal = Neuropsychopharmacology | volume = 25 | issue = 6 | pages = 904–14 | year = 2001 | pmid = 11750183 | doi = 10.1016/S0893-133X(01)00285-8 | doi-access = free }}</ref>
|-
| [[Loxapine]] || 63.9–175 || 300–590 || 122–390 || 300–2232 || 91–241 || Human || <ref name="pmid1346637" /><ref name="PDSP-Loxapine">{{cite web | title = PDSP K<sub>i</sub> Database | work = Psychoactive Drug Screening Program (PDSP) | author1 = Roth, BL | author2 = Driscol, J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://kidbdev.med.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testLigandDD=&testFreeRadio=testFreeRadio&testLigand=loxapine&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref>
|-
| [[Melperone]] || >15000 || 2400 || >15000 || 4400 || >15000 || Human || <ref name="pmid1346637" />
|-
| [[Mesoridazine]] || 10 || 15 || 90 || 19 || 60 || Human || <ref name="pmid1346637" />
|-
| [[Molindone]] || {{abbr|ND|No data}} || {{abbr|ND|No data}} || >10000 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12629531">{{cite journal | vauthors = Kroeze WK, Hufeisen SJ, Popadak BA, Renock SM, Steinberg S, Ernsberger P, Jayathilake K, Meltzer HY, Roth BL | title = H1-histamine receptor affinity predicts short-term weight gain for typical and atypical antipsychotic drugs | journal = Neuropsychopharmacology | volume = 28 | issue = 3 | pages = 519–26 | year = 2003 | pmid = 12629531 | doi = 10.1038/sj.npp.1300027 | doi-access = free }}</ref>
|-
| [[Olanzapine]] || 1.9–73 || 18–96 || 13–132 || 10–32 || 6–48 || Human || <ref name="pmid8822531">{{cite journal | vauthors = Bymaster FP, Calligaro DO, Falcone JF, Marsh RD, Moore NA, Tye NC, Seeman P, Wong DT | title = Radioreceptor binding profile of the atypical antipsychotic olanzapine | journal = Neuropsychopharmacology | volume = 14 | issue = 2 | pages = 87–96 | year = 1996 | pmid = 8822531 | doi = 10.1016/0893-133X(94)00129-N | doi-access = free }}</ref><ref name="pmid14642972" /><ref name="pmid10708730" />
|-
| [[Perphenazine]] || {{abbr|ND|No data}} || {{abbr|ND|No data}} || 1848 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12629531" />
|-
| [[Pimozide]] || {{abbr|ND|No data}} || {{abbr|ND|No data}} || 1955 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12629531" />
|-
| [[Quetiapine]] || 120–135 || 630–705 || 225–1320 || 660–2990 || 2990 || Human || <ref name="pmid8822531" /><ref name="pmid14642972" />
|-
| [[Remoxipride]] || >10000 || >10000 || >10000 || >10000 || {{abbr|ND|No data}} || Human || <ref name="pmid8822531" />
|-
| [[Rilapine]] || 190 || 470 || 1400 || 1000 || 1100 || Human || <ref name="pmid1346637" />
|-
| [[Risperidone]] || 11000 || ≥3700 || 13000 || ≥2900 || >15000 || Human || <ref name="pmid1346637" /><ref name="pmid8822531" />
|-
| [[Sertindole]] || {{abbr|ND|No data}} || {{abbr|ND|No data}} || 2692 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12629531" />
|-
| [[Tenilapine]] || 260 || 62 || 530 || 430 || 660 || Human || <ref name="pmid1346637" />
|-
| [[Thioridazine]] || 2.7 || 14 || 15 || 9 || 13 || Human || <ref name="pmid1346637" />
|-
| [[Thiothixene]] || >10000 || >10000 || >10000 || >10000 || 5376 || Human || <ref name="PDSP-Thiothixene">{{cite web | title = PDSP K<sub>i</sub> Database | work = Psychoactive Drug Screening Program (PDSP) | author1 = Roth, BL | author2 = Driscol, J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://kidbdev.med.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testDDRadio=testDDRadio&testLigandDD=thiothixene&testLigand=&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref>
|-
| [[Thiothixene|''cis''-Thiothixene]] || 2600 || 2100 || 1600 || 1540 || 4310 || Human || <ref name="pmid1346637" />
|-
| [[Tiospirone]] || 630 || 180 || 1290 || 480 || 3900 || Human || <ref name="pmid1346637" />
|-
| [[Trifluoperazine]] || {{abbr|ND|No data}} || {{abbr|ND|No data}} || 1001 || {{abbr|ND|No data}} || {{abbr|ND|No data}} || Human || <ref name="pmid12629531" />
|-
| [[Ziprasidone]] || ≥300 || >3000 || >1300 || >1600 || >1600 || Human || <ref name="pmid14642972" /><ref name="PDSP-Ziprasidone">{{cite web | title = PDSP K<sub>i</sub> Database | work = Psychoactive Drug Screening Program (PDSP) | author1 = Roth, BL | author2 = Driscol, J | publisher = University of North Carolina at Chapel Hill and the United States National Institute of Mental Health | access-date = 14 August 2017 | url = https://kidbdev.med.unc.edu/databases/pdsp.php?knowID=0&kiKey=&receptorDD=&receptor=&speciesDD=&species=&sourcesDD=&source=&hotLigandDD=&hotLigand=&testLigandDD=&testFreeRadio=testFreeRadio&testLigand=ziprasidone&referenceDD=&reference=&KiGreater=&KiLess=&kiAllRadio=all&doQuery=Submit+Query}}</ref>
|-
| [[Zotepine]] || 18 || 140 || 73 || 77 || 260 || Human || <ref name="pmid1346637" />
|- class="sortbottom"
| colspan="8" | Values are K<sub>i</sub> (nM). The smaller the value, the more strongly the drug binds to the site.
|}
==See also==
{{col div|colwidth=30em}}
* [[Anticholinergic]]
* [[Muscarinic agonist]]
* [[Nicotinic acetylcholine receptor]]
* [[Nicotinic agonist]]
* [[Nicotinic antagonist]]
* [[Parasympatholytic]]
{{colend}}
==References==
{{Reflist|2}}
==External links==
* [http://www.pharmatutor.org/pharmacology/ans-pharmacology/anti-cholinergics.html Effects of Muscarinic Antagonist]
* [http://cvpharmacology.com/antiarrhy/atropine.htm Atropine (Muscarinic Receptor Antagonist)], Cardiovascular Pharmacology Concepts, Richard E. Klabunde, PhD
* {{MeshName|Muscarinic+antagonists}}
* {{MeshPharmaList|82018727}}
{{Pharmacomodulation}}
{{Navboxes
| title = [[Medicine|Medical uses]]
| titlestyle = background:#ccccff
| list1 =
{{Drugs for functional gastrointestinal disorders}}
{{Urologicals}}
{{Antiparkinson}}
{{Hallucinogens}}
{{Mydriatics and cycloplegics}}
{{Opthalmologicals}}
}}
{{Acetylcholine receptor modulators}}
[[Category:Muscarinic antagonists| ]]