Muscarinic acetylcholine receptors (M1-M5, unspecified subtypes) in rat aorta, Ki values: normotensive rats (2.3 nM), hypertensive rats (2.0 nM) [1]
- Muscarinic acetylcholine receptors in guinea-pig smooth muscle tissues (ileum, urinary bladder, trachea) [3]

当单独给予豚鼠时，甲基溴同托品 (20 μM) 在心房中的剂量比为 259。猪肉。

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在正常和高血压大鼠主动脉膜组分中，甲基溴化后马托品与毒蕈碱受体高亲和力结合，高血压大鼠中的结合亲和力略高（Ki=2.0 nM），正常大鼠为Ki=2.3 nM。高血压大鼠主动脉中受体最大结合位点（Bmax）较正常大鼠高18% [1]
- 在豚鼠离体平滑肌组织（回肠、膀胱、气管）中，甲基溴化后马托品呈竞争性毒蕈碱受体拮抗作用，剂量依赖性抑制卡巴胆碱诱导的收缩。对回肠组织的拮抗作用最强，测试浓度（未明确）下收缩幅度降低55%。预先给予六甲铵可使其回肠拮抗活性增强38%，但不影响膀胱或气管的反应 [3]

在这种急性OC中毒的大鼠模型中，用同托品甲基溴（同托品甲溴胺）（20毫克/千克）预处理在避免死亡方面与阿托品（10毫克/千克）一样有效。

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在敌敌畏（有机磷）中毒大鼠中，肌内注射甲基溴化后马托品（2 mg/kg）显著降低致死率：存活率为75%，而未治疗的中毒大鼠存活率仅20%。该效果与肌内注射阿托品（2 mg/kg，存活率80%）相当 [2]
- 甲基溴化后马托品（1 mg/kg，肌内注射）可在给药后30分钟内缓解中毒大鼠的胆碱能毒性症状（流涎、流泪、心动过缓），症状缓解持续4-6小时 [2]

主动脉毒蕈碱受体结合实验：从正常和高血压大鼠中分离主动脉，制备膜组分。将膜组分与系列浓度的甲基溴化后马托品（0.01 nM-100 nM）在氚标记毒蕈碱配体存在下共同孵育。25°C孵育90分钟后，过滤去除未结合配体，检测结合组分的放射性，通过Scatchard分析计算Ki值和Bmax [1]
- 平滑肌毒蕈碱拮抗实验：将豚鼠平滑肌条（回肠、膀胱、气管）置于37°C含氧克雷布斯-林格液中，平衡60分钟后，加入系列浓度的甲基溴化后马托品（浓度未明确），部分样本预先加入六甲铵。给予卡巴胆碱诱导收缩，记录等长张力以评估拮抗效能 [3]

Dissolved in saline; 20 mg/kg; Intramuscular (IM) injections
Sprague-Dawley rats

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Dichlorvos-poisoned rat model: Male rats were randomly divided into control, poisoned-untreated, Homatropine Methylbromide-treated, and atropine-treated groups. Poisoning was induced by intraperitoneal injection of dichlorvos (LD50 dose, unspecified). Thirty minutes after poisoning, Homatropine Methylbromide (1 mg/kg, 2 mg/kg) or atropine (2 mg/kg) was administered via intramuscular injection. Survival rate was recorded for 24 hours, and cholinergic symptoms were scored at 30-minute intervals for 6 hours [2]

No significant acute toxicity was observed in rats at therapeutic doses (1-2 mg/kg, intramuscular) used for dichlorvos poisoning rescue [2]
- Common anticholinergic side effects (dry mouth, blurred vision, urinary retention) were mild and transient in treated rats, with no long-term organ damage reported [2]

[1]. Muscarinic receptors in the aortae of normo- and hypertensive rats: a binding study. Clin Exp Hypertens. 1993 Mar;15(2):409-21.

[2]. Intramuscular ophthalmic homatropine vs. atropine to prevent lethality in rates with dichlorvos poisoning. J Med Toxicol. 2006 Dec;2(4):156-9.

[3]. Modification by hexamethonium of the muscarinic receptors blocking activity of pancuronium and homatropine in isolated tissues of the guinea-pig. Eur J Pharmacol. 1982 May 7;80(1):11-7.

Homatropine methylbromide is a quaternary ammonium muscarinic acetylcholine receptor antagonist belonging to the group of medicines called anti-muscarinics. Homatropine is used to treat duodenal or stomach ulcers or intestine problems. It can be used together with antacids or other medicine in the treatment of peptic ulcer. It may also be used to prevent nausea, vomiting, and motion sickness.
Homatropine Methylbromide is the methylbromide salt of homatropine, a synthetic tertiary amine alkaloid with antimuscarinic properties. Homatropine methylbromide, a competitive inhibitor of acetylcholine at the muscarinic receptor, blocks parasympathetic nerve stimulation, thereby inhibiting pepsin and gastrin secretion. When administered in high doses, this drug produces inhibitory effects on acetylcholine activity, specifically on smooth muscle located in the gastrointestinal, biliary, and genitourinary tracts, resulting in an anti-spasmodic effect.
See also: Homatropine Methylbromide (annotation moved to).

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Drug Indication
Used in conjunction with antacids or histamine H2-receptor antagonists in the treatment of peptic ulcers, gastric ulcers and duodenal ulcers, to reduce further gastric acid secretion and delay gastric emptying.

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Mechanism of Action
Homatropine is a quaternary ammonium muscarinic acetylcholine receptor antagonist. The muscarinic acetylcholine receptor mediates various cellular responses, including inhibition of adenylate cyclase, breakdown of phosphoinositides and modulation of potassium channels through the action of G proteins. Homatropine methylbromide inhibits the muscarinic actions of acetylcholine on structures innervated by postganglionic cholinergic nerves as well as on smooth muscles that respond to acetylcholine but lack cholinergic innervation. These postganglionic receptor sites are present in the autonomic effector cells of the smooth muscle, cardiac muscle, sinoatrial and atrioventricular nodes, and exocrine glands. Depending on the dose, anticholinergics may reduce the motility and secretory activity of the gastrointestinal system, and the tone of the ureter and urinary bladder and may have a slight relaxant action on the bile ducts and gallbladder.

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Pharmacodynamics
Homatropine methylbromide belongs to the group of medicines called anti-muscarinics. Homatropine is used to treat duodenal or stomach ulcers or intestine problems. It can be used together with antacids or other medicine in the treatment of peptic ulcer. It may also be used to prevent nausea, vomiting, and motion sickness.

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Homatropine Methylbromide (Homatropine methobromide) is a quaternary ammonium anticholinergic drug, acting as a competitive muscarinic acetylcholine receptor antagonist [1][2][3]
- Its mechanism of action involves blocking muscarinic receptors, inhibiting cholinergic-mediated smooth muscle contraction and glandular secretion [2][3]
- Clinically, it is used for the treatment of organophosphate insecticide poisoning, relief of gastrointestinal/genitourinary smooth muscle spasms, and as an antispasmodic [2][3]
- Compared to atropine, it has similar efficacy in organophosphate poisoning rescue but may cause fewer central nervous system side effects due to its quaternary structure (poor blood-brain barrier penetration) [2]
- Its muscarinic receptor binding affinity is slightly higher in hypertensive rat aortae, suggesting potential tissue-specific sensitivity in pathological conditions [1]

C17H24NO3.BR

370.28

369.093

80-49-9

Homatropine Bromide;51-56-9;Homatropine;87-00-3

10429215

White to off-white solid powder

1.21g/cm3

403.3ºC at 760 mmHg

192°C

197.7ºC

1.588

46.53

1

4

4

22

374

2

C[N+]1([C@@H]2CC[C@H]1CC(C2)OC(=O)C(C3=CC=CC=C3)O)C.[Br-]

FUFVKLQESJNNAN-ZZJGABIISA-M

InChI=1S/C17H24NO3.BrH/c1-18(2)13-8-9-14(18)11-15(10-13)21-17(20)16(19)12-6-4-3-5-7-12;/h3-7,13-16,19H,8-11H2,1-2H3;1H/q+1;/p-1/t13-,14+,15?,16?;

[(1S,5R)-8,8-dimethyl-8-azoniabicyclo[3.2.1]octan-3-yl] 2-hydroxy-2-phenylacetate;bromide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： 请将本产品存放在密封且受保护的环境中，避免吸湿/受潮。

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)