Question

약 먹고 푹 쉬어라 -고 is used to list two unrelated actions. The use of the sequential marker -아/어서 implies that two actions are intrinsically linked; the second action commonly wouldn't be possible without performing the first action. -고 can replace -아/어서. However, the use of -어/아서 is preferred whenever there is an intrinsic connection between the two clauses.

Accepted Answer

Take medication and get a good rest

Front	약 먹고 푹 쉬어라
Back	Take medication and get a good rest
Notes	-고 is used to list two unrelated actions. The use of the sequential marker -아/어서 implies that two actions are intrinsically linked; the second action commonly wouldn't be possible without performing the first action. -고 can replace -아/어서. However, the use of -어/아서 is preferred whenever there is an intrinsic connection between the two clauses.

고 약 먹고 푹 쉬어라 Medication Good Rest