Myasthenia Gravis and Oxybutynin
Evan B. Stubbs
estubbs at orion.it.luc.edu
Tue Jul 25 18:26:33 EST 1995
Andrew Ray (aray at emory.edu) wrote:
: In article <3v0j8d$3gkf at ns4-1.CC.Lehigh.EDU>, x011 at Lehigh.EDU writes:
: >In article <420402306wnr at tropheus.demon.co.uk>, Steve Wolstenholme
: <steve at trophe
: >us.demon.co.uk> writes:
: >>About 4 years ago I was showing symptoms of Myasthenia
: >>Gravis. My GP was fairly certain of his diagnosis but he
: >>sent me for tests just in case. I had various tests
: >>including some antibody test (which I can't remeber the
: >>name of) and an injection that immediately relieved the
: >>facial symptoms and made me feel quite well for a few
: >>seconds. The antibody test that was supposed to be a good
: >>method of diagnosis proved negative.
: >>My symptoms continued to get worse for a month or so but
: >>then I ran out of a tablet I was taking for a different
: >>problem and I went without them for a few days. The
: >>Myasthenia Gravis symptoms dissapeared within a week and
: >>they have not returned. The tablets were 5mg Oxybutynin
: >>hydrochloride. I no longer take the tablets.
: >>Steve Wolstenholme
: >Very interesting. Oxybutynin may be useful as a medicine to
: >treat the disease assuming an opponent reaction occurred.
: >Ron Blue
: I've never heard of oxybutynin (it's probably not on the market in the US), but
: since the antibody test was negative, your GP was wrong in his diagnosis of
: Myasthenia Gravis. However, since a drug that blocks activity at peripheral
: nicotinic cholinergic receptors (i.e. at the neuromuscular junction) could
: cause symptoms similar to MG, that would be my "suspect". Oxybutynin might
: do that - if someone knows what it treats, that would be another clue. If it
: blocks cholinergic receptors, that would explain why you're not taking it
: helped the symptoms. It may actually affect cholinergic metabolism, but it is
: doubtful since you didn't mention any other symptoms of loss of cholinergic
: function, and since this would probably cause general loss of muscle tone.
: As for treating the disease, that would depend on where oxybutynin has its
: Andrew Ray
: Emory University
: Dept of Neuroscience
: aray at emory.ed
According to the PDR, oxybutynin chloride (Ditropan syrup-Marion)
is an anticholinergic agent. It is/was used for the treatment of uninhibited
neurogenic and reflex neurogenic bladder. This agent is thought to
inhibit muscarinic receptors on smooth muscles, with no blocking effects
at skeletal neuromuscular junctions or autonomic ganglia.
Although no antinicotinic effects are indicated, it does appear
suspicous that the symptoms alleviated after discontinuing this
medication. Ditropan may produce drowsiness/blurred vision and related
CNS effects in some individuals.
Evan Stubbs, Ph.D.
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