Learn Spanish (Latin America): El doctor acababa de llevarse la medicina cuando el efecto empezó. - The doctor had just taken away the medicine when the effect began.

This is an example of a verb slightly changing its meaning when a pronoun like se is added. While llevar generally means to carry or to transport, making it the pronominal verb llevarse changes the meaning to taking something away or taking something with oneself. The doctor did not just carry the medicine; he took it away with him.

Why is acababa de in the imperfect tense instead of the preterite?

The phrase acabar de followed by an infinitive means to have just done something. When telling a story in the past, we use the imperfect tense (acababa de) to set the ongoing background scene: the doctor had just taken the medicine away. This sets the stage for the main interrupting event, which uses the preterite tense because it was a sudden, completed action: the effect began (empezó).

Could the se go before the verb instead of being attached to the end of llevar?

Yes! When you have a conjugated verb followed by an infinitive, you can attach the pronoun to the end of the infinitive, as in acababa de llevarse. However, you can also place it right before the conjugated verb. Saying El doctor se acababa de llevar la medicina is perfectly correct and means the exact same thing.

Does the se in llevarse refer to the doctor or the medicine?