Chemotherapy can damage the mucosa lining the oesophageal tract and make the effects of radiation therapy worse. Immunosuppression can increase the risk of oesophageal infection, particularly viral and fungal.^11,30

Other drugs considered to have the potential to cause oesophageal damage include:^6,11

• antibiotics with acid pH, such as tetracyclines and macrolide antibiotics such as erythromycin and clindamycin
• aspirin and non-steroidal anti-inflammatory drugs
• iron supplements
• vitamin C
• bisphosphonates such as alendronate
• methylxanthines such as theophylline
• antiarrhythmics such as quinidine
• potassium chloride

L-dopa and digoxin have been associated with dysphagia, but the mechanism is unclear.⁶