Silver nitrate versus tetracycline in pleurodesis for malignant pleural effusions; a prospective randomized trial

BACKGROUND: In this study, we aimed to investigate the effectiveness of silver nitrate (SN) versus tetracycline in pleurodesis among patients with malignant pleural effusion (MPE). METHODS: In this prospective randomized clinical trial, patients with unilateral MPE candidate for pleurodesis were enrolled. The patients randomly allocated in two groups for receiving 20 mL 0.5% SN or 2.5 g tetracycline diluted in 30 cc normal saline and 0.1% lidocaine, through the chest tube. Patients were followed-up immediately (during 24 h) and 1-month after the procedure for evaluating recurrence of the pleural effusion using chest radiograph. They were clinically evaluated for chest pain and/or dyspnea and fever using a questionnaire that completed by the surgeon. The results were compared with two groups. RESULTS: During this trial, 50 patients with MPE candidate for pleurodesis were selected and randomized into two interventional groups (25 patients in each group). Immediate and late recurrence of pleural effusion after pleurodesis were similar in two groups (P > 0.05). All patients in tetracycline group had fever and chest pain, but in SN group fever and chest pain were reported in 3 (12%) and 12 (48%) of patients, respectively (P < 0.05). CONCLUSION: SN is at least as effective as tetracycline for MPE treatment. In addition, its side effects were lower than tetracycline. Other advantages of SN are its low cost, availability, and safety. For more accurate results, it is recommended to design further trials with larger sample size and with lower doses of both SN and tetracycline.