Rebecca Leighton, 27, is accused of six counts of causing damage with intent to endanger life or being reckless as to whether life was being endangered.
The Crown Prosecution Service says she is alleged to have tampered with medical products, saline ampoules and saline bags at Stepping Hill Hospital.
Ms Leighton is due to appear before magistrates in Manchester.
The 27-year-old, of Buxton Road, Heaviley, Stockport, also faces one count of theft of medicine from the hospital.
She was arrested on Wednesday by police investigating the deaths of Tracey Arden, 44, Arnold Lancaster, 71, George Keep, 84, Derek Weaver, 83, and Vera Pearson, 84.
Mr Weaver, from Stockport, died on Thursday after suffering a hypoglycaemic episode on 11 July - a day after he was admitted from his interim care home with breathing problems.
Multiple sclerosis sufferer Ms Arden, of Heaviley, died on 7 July and retired photographer Mr Lancaster, of Romiley, died on 11 July.
Mr Keep, of Cheadle, died on 14 July after being admitted to the hospital with a broken hip, while on the same day Mrs Pearson also died.
Police said saline solution at the hospital had been contaminated with insulin, which can cause low blood sugar.
A 41-year-old man remains critically ill in hospital.
Police are also looking at the treatment of eight other patients since 7 July.