Yasmin is a combination pill that uses a progestin that can trigger an increase in potassium load in the body. As such, there are some women who may suffer serious complications if they are at risk for kidney, liver or adrenal system diseases. The added burden of potassium can upset the sodium-potassium balance in the heart bringing on a heart attack.
As to the drug’s mechanisms of action, they are identical to other hormonal contraceptives. I did visit the Berlex Pharmaceuticals webpage to see if they had posted their PDR sheet. By linking on to their “Physician Information” you can read the FDA information. Simply go to http://www.yasmin-us.com. Look at the very bottom of their screen and locate the button for “Prescribing Information,” then choose the option for physicians. There you will note that Yasmin acts to “prevent” pregnancy in the same three ways that are common with other hormonal birth control products, including by prevention of implantation.
I quote directly from the text under Clinical Pharmacology:
“Combination oral contraceptives (COCs) act by suppression of gonadotropins. Although the primary mechanism of this action is inhibition of ovulation, other alterations include changes in the cervical mucus (which increases the difficulty of sperm entry into the uterus) and the endometrium (which reduces the likelihood of implantation).”