High rpm - low speed - Morning sickness ???

Hello All,
This is my first message in this forum.
I have a 1990 Acura Integra 4-dr and facing a wierd problem. When I start driving the car the rpm goes to ~5000 and it reaches only a max speed of 50-55mph. After driving for about a mile, I feel as if something is getting released and the rpm drops down to 2500 after which I can increase the speed beyound 60mph.
What could be the reason for this problem ?.
Thanks.

Added: This problem happens only once in the morning. After I come back from work at around 6pm, I use the car the next morning at 8:30 am.

ok...i'm not quite following you here. you say it gets up to 5k rpms but then drops down to 2.5k rpms and its faster? is this an auto or a stick? do you let your car warm up before you start driving? i usually wait for the idle rpm rate to drop below 1k.

Well. I did try that before posting. I ran the car in the idle mode for more than 5 minutes, rpm dropped below 1k and still I faced the same problem.
Today I changed the transmission oil. I will wait and see if I face the same problem tomorrow morning.
Thank you for your response.
Cheers.

I had the same problem with my 92. I checked the spark plugs and wires and replaced them. Then for the heck of it I replaced the ignition coil and the rotor because it was sparking bad. It probably has to do with the spark. If it's not firing on all cylinders then you've got some funky idling and weird speed problems. So check that stuff, just a suggestion.