Dear chblackm,
I have taken hyoscyamine 0.375 mgs ER tablets for Pancreatic
Acute Attack pain. I have taken it as needed, not on an ongoing daily basis. Only when I have acute Pancreatic pain.
My gastroenterologist prescribed it for me, saying it is an organ relaxer. He told me it would stop the pain of an acute pancreatic attack. After about two hours, it did successfully ease the acute pain of a pancreatic attack. It did not always work and when I had nine acute Pancreatic attacks for nine days straight, I needed more and went to the emergency room by ambulance. They sent me home asking me to put up with the pain. I was taken to the hospital by ambulance one week later, unable to eat and and with a temperature of 102.8. They could not see the stones blocking my distal common bile duct on cat scan and were going to send me home. The ER doc told me I did not have pancreatitis. I told him he could not tell me what I had or did not have and that I needed to be admitted. They finally saw the one centimeter stone + sludge on an MRI, but were again going to send me home and have me have a second MRI as an out-patient. I insisted that while I was there, to do the MRI again in hospital. That is when they finally saw the huge stone blocking my bile ducts affecting the pancreas and liver. My liver enzymes went up 1000%. This freaked them out and got them moving on removing the stone.
The stone and sludge were removed by Dr. Justin Nudell, an excellent gastroenterologist, by upper endoscopy. After the stone was removed, they noticed bowel gas and rushed me back to surgery for an open abdominal suture and patch of a colon leak that was ongoing since 2002. I was one sick puppy. This was two years ago, and it is only now that I feel as though I have healed from the surgery.
I still have the hyoscyamine available if I have another stone blockage and further pancreatic pain. Does not work for liver pain, though.
It is a muscle relaxer - I am glad it is working for your esophageal spasms.
There are better muscle relaxers for Fibromyalgia pain that can be taken on an ongoing daily basis.
Sincerely,
Karen 1001

I have not had any side effects other than a dry mouth..

VeraBalogh, I also have the disolving pill. I only take it if I feel a spasm coming on...it really does seem to help...

Are there any side effects this muscle relaxer?

Yes, I have taken them to relieve pain caused by reflux and muscle spasm at the opening of the stomach. Increadibly helpful for me, helps almost instantly, I have the dissolving type of pill. Thank you for sharing your impression regarding relieving fibromialgia pain. I will check and take some since it has zero side effect on me. It is supposedly a smooth muscle relaxer so it might be helpful! Hugs