M1選擇性拮抗劑，用於治療消化性潰瘍 ，因為它能減少胃酸分泌，降低肌肉痙攣 。
由於它的特性，能選擇性作用於睫狀肌麻痺，但卻較不會讓瞳孔放大。因此近年來有研究將它用於近視控制。
如下面這一篇，美國兩年的多中心、隨機、雙盲、安慰劑控制研究的2% Pirenzepine在兒童近視方面的安全性與有效性的論文。
實驗對象:
8~12歲，等值球面在-0.75D~-4.00D，散光不大於1.00D，以2:1的比例隨機分配到實驗組(2% Pirenzepine眼凝膠)與對照組，一天點用兩次。實驗結果測量為散瞳後之電腦驗光數據。
結果:
實驗開始時，實驗組 -2.10 +/- 0.90 D (mean +/- SD) (n = 117) ，對照組 -1.93 +/- 0.83 D (n = 57; p = 0.22)。
一年後，實驗組近視平均增加 -0.26 D，對照組增加-0.53 D (p < 0.001)
84個患者選擇繼續第二年的實驗，(pirenzepine = 53, placebo = 31)
第二年，實驗組近視平均增加 -0.58 D，對照組增加-0.99 D (p = 0.008)
13個實驗組患者(11%)在第一年時，由於藥物副作用退出實驗。第二年時有一位退出。
結論:
Pirenzepine 眼凝膠 2% 相比於安慰劑在減緩近視增加方面是有效的，而在兩年治療期間臨床上的安全性是可接受的。
J AAPOS. 2008 Aug;12(4):332-9. Epub 2008 Mar 24.
Two-year multicenter, randomized, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia.
Siatkowski RM, Cotter SA, Crockett RS, Miller JM, Novack GD, Zadnik K; U.S. Pirenzepine Study Group.
Dean McGee Eye Institute/University of Oklahoma Department of Ophthalmology, Oklahoma City, Oklahoma. USA.
Comment in:
Abstract
PURPOSE: To evaluate if the safety and efficacy of the relatively selective M1-antagonist, pirenzepine, in slowing the progression of myopia in children is sustained over a 2-year period.
METHODS: This was a multicenter, parallel-group, placebo-controlled, double-masked, randomized clinical trial. Enrolled were children aged 8 to 12 years, with entry spherical equivalent refractive error of -0.75 to -4.00 D and astigmatism
RESULTS: At study entry, spherical equivalent was -2.10 +/- 0.90 D (mean +/- SD) for the pirenzepine group (n = 117) and -1.93 +/- 0.83 D for the placebo group (n = 57; p = 0.22). At 1 year, there was a mean increase in myopia of 0.26 D in the pirenzepine group versus 0.53 D in the placebo group (p < 0.001). Eighty-four patients elected to continue for a second year (pirenzepine = 53, placebo = 31). At 2 years, the mean increase in myopia was 0.58 D for the pirenzepine group and 0.99 D for the placebo group (p = 0.008). Thirteen (11%) pirenzepine patients dropped out due to adverse effects in the first year, and 1 did so in the second year.
CONCLUSIONS: Pirenzepine ophthalmic gel 2% was effective compared with placebo in slowing the progression of myopia over a 2-year treatment period and demonstrated a clinically acceptable safety profile.
PMID: 18359651 [PubMed - indexed for MEDLINE]
Invest Ophthalmol Vis Sci. 2012 Aug 24;53(9):5827-37. doi: 10.1167/iovs.12-9943.
回覆刪除Muscarinic antagonist control of myopia: evidence for M4 and M1 receptor-based pathways in the inhibition of experimentally-induced axial myopia in the tree shrew.
Arumugam B, McBrien NA.
Source
Department of Optometry and Vision Sciences, The University of Melbourne, Victoria, Australia.
Abstract
PURPOSE:
The broadband muscarinic antagonist atropine is effective in stopping the progression of myopia in animals and humans. The partially selective M(1)/M(4) antagonist pirenzepine also slows progression of myopia, although not as effectively as atropine. Due to the supra maximal doses utilized in these studies, it is unclear if this antimyopia effect occurs through a receptoral-based mechanism, and if so, which receptors are involved. Studies in chicks indicate the involvement of the M(4) muscarinic receptor. The current study investigated the effect of the highly selective muscarinic antagonists Muscarinic Toxin 3 (MT3) (M(4) selective) and Muscarinic Toxin 7 (MT7) (M(1) selective) on experimental myopia in a mammalian model.
METHODS:
Tree shrews (n = 23) underwent daily intravitreal injections of MT3, MT7, or vehicle (phosphate buffered saline) for five days in the treated eye, combined with deprivation of vision with a translucent occluder (MD). The contralateral eye was unocccluded and underwent intravitreal injections of vehicle for the same period. Two additional groups (n = 10) underwent daily intravitreal injections of MT7 or vehicle for 10 days in the treated eye combined with negative lens (-9.5 diopter [D]) defocus (LIM). The control eye was injected with saline and wore a plano lens.
RESULTS:
Both MT3 and MT7 treatment reduced the development of deprivation-induced myopia (treated-control eye [T-C]; vehicle-MD; -4.3 ± 0.6 D versus MT3-MD; -0.7 ± 0.2 D and MT7-MD; -0.7 ± 0.4 D; P < 0.001). MT7 treatment was effective at inhibiting lens-induced myopia (T-C; vehicle-LIM; -4.6 ± 0.5 D versus MT7-LIM; 0.2 ± 0.2 D; P < 0.05).
CONCLUSIONS:
The findings demonstrate that inhibition of form-deprivation myopia by muscarinic antagonists involves both M(4) and M(1) muscarinic receptor signaling pathways in mammals.
PMID: 22836762 [PubMed - in process]