Are there any medications that can increase the likelihood of sepsis

Probably. Any immunosuppressant increases the likelihood of serious infection and any serious infection can lead to sepsis, shock and death in an immune compromised patient. The list of immune suppressants is long, but includes drugs to treat cancer, autoimmune diseases, or prednisone.
Absolutely. Anything that suppresses your immune system such as steroids commonly used for multiple disorders including asthma; chemotherapy used for cancer; other biologicals used for collagen vascular diseases, ulcerative colitis etc. The list is very long.