Pulmonary Embolism Support Group
By far the most common form of pulmonary embolism is a thromboembolism, which occurs when a blood clot, generally a venous thrombus, becomes dislodged from its site of formation and embolizes to the arterial blood supply of one of the lungs. Symptoms may include difficulty breathing, pain during breathing, and more rarely circulatory instability and death.
On the other hand, my FIL started drinking tons of cranberry juice last year. A few weeks later, his INR was through the roof. So, maybe don't go with daily gallons, but a little in a cosmo probably wouldn't cause an issue.
(And, if you're really worried, get your INR checked a couple days later!)
There are also the odd report which states that excessive intake can be problematic: A couple of cocktails will probably affect you more from the alcohol, rather than the cranberries.
Man, a nice ice cold vodka martini sounds good right now.