Do you know if there are side affects to in the long term use of simvastatin, or any of the statin drugs?

Extremely safe: About 1 in 100,000 can get serious liver injury or rhabdomyolysis. These are the only serious long term side effects. There is a slightly increased incidence of diabetes which is out weighed by the benefit. The commonest side effect, muscle aching, occurs in about 1 in 10 but resolves with withdrawal of the medicine.

Statin: Glucose intolerance, impaired exercise training and muscle aches have all been reported.