2 doctors agreed: No: I know of no research that shows xenical can cause a false-positive drug test. All xenical does is block some of the fat from your diet from being absorbed, thus decreasing your calorie intake. This shouldn't cause either a urine or a blood drug test to become positive.
The total flight duration from New York, NY to Dominican Republic is 3 hours, 31 minutes. This assumes an average flight speed for a commercial airliner of 500 mph, which is equivalent to 805 km/h or 434 knots. It also adds an extra 30 minutes for take-off and landing.
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