nwyatt, back spasms are an uncommon side effect with Tymlos. It is speculated that the spasms are a response to increased bone turnover.
You should contact your doctor who should be able to get the insurance to switch you back to Forteo. Two clicks might be closer to the Forteo dose. You could pause the Tymlos until you hear from the endocrinologist.
Are the spasms worse just after the injection, worse at night, or sporatic?
Hypercalcemia can cause muscle spasms. Forteo or Tymlos can cause hypercalcemia.