It is best to change the oil and filter more frequently.
If you are fussy you can drain the old oil and add a quart of new stuff and run the engine for a minute on tick over, and drain the new stuff and then change the filter, and add the proper amount to max on dip stick.
Some people add magic solvents but these are only necessary if you have hydrulic tappets and the engine has not been run for an interval. They remove gum that will stop the tappets self adjusting.
Adding solvents to the petrol is also necessary after an interval of disuse.
Noel