Efficacy of Non-opioid Drugs in Addition to Opioid Therapy for Cancer Pain Management

Inclusion Criteria: * Inpatient setting (discharge possible, if patient returns for End of Study Visit) * Diagnosis of metastatic or locally advanced cancer * Cancer pain as defined by IASP (International Association for the Study of Pain) * Cancer pain therapy with opioids indicated for pain management or start thereof at baseline (drug, dose, and route at treating physician's discretion) * Average daily pain intensity ≥ 3 on NRS (Numeric Rating Scale) * Ability to swallow oral medication * Informed Consent as documented by signature Exclusion Criteria: * History of allergy or allergy-like symptoms (bronchospasm, urticaria or severe cutaneous adverse reactions (SCARs)) or hypersensitivity to dipyrone (or other pyrazolones or pyrazolidines) or ibuprofen (or other Non-steroidal anti-inflammatory drug incl. acetylsalicylic acid) * Moderate to severe renal insufficiency (creatinine-eGFR (estimated Glomerular Filtration Rate) \<45 ml/min) * Severe heart failure (New York Heart Association class III-IV) * Severe hepatic impairment (liver cirrhosis with ascites) or hepatic porphyria * History of agranulocytosis induced by dipyrone (or other pyrazolones or pyrazolidines) * Active gastric and/or duodenal ulcers or bleeding * History of recurrent gastric and/or duodenal ulcers or gastrointestinal bleeding (≥2 distinct episodes of proven ulceration or bleeding) or increased tendency to bleeding * Third trimester of pregnancy * Breastfeeding * G6PD deficiency * Inflammatory bowel dis…