I have been on omeprazole for 10 years. i started taking 20 mg but after chemo 2 years ago ,acid reflux got worse. i am currently on 40 mg for the last 2 years. how safe is long term use of omeprazole. doctor said i can try 20 one day and then 40?

Osteoporosis, B12 deficiency, gut bacteria change etc can occur . Your doc will/ should keep an eye for that

Although there can be some long-term side effects of PPIs, there also can be long-term deleterious effects of chronic acid reflux. Whether you need to be on these medications long-term depends on the severity of your symptoms. You should talk this over with your gastroenterologist and convey your concerns. Good luck.