On a recent long-haul flight (HKG-JFK), my eustation tubes closed up (I guess as can be expected), and I developed a moderately painful ear infection. I am on my third day of antibiotics (amoxicillan), coupled with pseudophedrin. The pain has subsided, but my ears still are congested.

For future reference, are there prophylactic measures one can take to prevent or reduce the risk of this happening?