What medication did Elly Koss take when she had Streptococcal sore throat?
medication refers to DESCRIPTION from medications; Streptococcal sore throat refers to REASONDESCRIPTION like 'Streptococcal sore throat%';
SELECT T2.description FROM patients AS T1 INNER JOIN medications AS T2 ON T1.patient = T2.PATIENT WHERE T1.first = 'Elly' AND T1.last = 'Koss' AND T2.reasondescription = 'Streptococcal sore throat (disorder)'