Mylan 216 pill is Furosemide 40mg pill - a loop diuretic used in the treatment of congestive heart faillure, hypertension, edema, pulmonary edema, ascites, oliguria, hypercalcernia, nonobstructive oliguria, and renal failure. The medication is also used in patients operated on for renal transplantation. It prevents accomulating too much salt in the body, removing it through urinary tracts.

Furosemide is also known as Lasix.

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What you've got there is 40 mg of furosemide.
Furosemide is a loop diuretic (water pill) that prevents your body from absorbing too much salt, allowing the salt to instead be passed in your urine.