He took an OTC indigestion remedy, and his pain eventually resolved after a couple of hours.
 His pain worsened after taking an over the counter medication
(ROOT (S (NP (PRP He)) (VP (VP (VBD took) (NP (DT an) (NNP OTC) (NN indigestion) (NN remedy))) (, ,) (CC and) (NP (NP (PRP$ his) (NN pain)) (VP (ADVP (RB eventually)) (VBN resolved) (PP (IN after) (NP (NP (DT a) (NN couple)) (PP (IN of) (NP (NNS hours)))))))) (. .)))
(ROOT (S (NP (PRP$ His) (NN pain)) (VP (VBD worsened) (PP (IN after) (S (VP (VBG taking) (PP (DT an) (PP (IN over) (NP (DT the) (NN counter) (NN medication))))))))))
( He ( ( ( ( ( took ( an ( OTC ( indigestion remedy ) ) ) ) , ) and ) ( ( his pain ) ( eventually ( resolved ( after ( ( a couple ) ( of hours ) ) ) ) ) ) ) . ) )
( ( His pain ) ( worsened ( after ( taking ( an ( over ( the ( counter medication ) ) ) ) ) ) ) )