When prescription patents expire, generics cost less but not a sure thing

DEAR DR. ROACH

» In these days of quickly rising drug costs, some companies lose their patents, allowing for generic versions, but others do not. I use a brand-name HFA inhaler for my COPD, and it should have gone off patent eight years ago. What change could possibly keep it under patent two times? — J.C.A.

ANSWER » All patents for drugs expire, but in order for a generic drug to be approved, it must pass stringent testing by the Food and Drug Administration.

One commonly used combination inhaler, Advair, went off patent in 2010, but no generic was approved until 2019. Since brandname Advair is expensive ($440 per inhaler, which lasts a month, at Goodrx. com), many patients were anxiously awaiting a generic alternative. It’s finally available (fluticasone/salmeterol) for about $115 an inhaler on GoodRx.

Manufacturers do sometimes change the drug slightly to extend their patents of their best-selling drugs. For many years the Prilosec brand of omeprazole was very expensive. Just before a generic became available, the manufacturer released a new drug, esomeprazole (Nexium). It is almost exactly the same drug.

DEAR DR. ROACH » Can radiation cause diverticulitis? — S.W.

ANSWER » Radiation damage to the colon is common when higher doses of radiation are used in treatment of cancer of the prostate, rectum, anus, cervix, uterus, bladder and testes.

Over time, mild and moderate acute damage usually repairs itself, but severe damage can lead to chronic radiation-induced symptoms that last for years. The most common symptoms in acute radiation damage are bowel symptoms, like diarrhea, mucus and urgency. People with chronic disease may have bleeding and other symptoms.

Diverticula are pouches in the wall of the colon. These appear in many people, especially as we age, and are more likely in people with a history of constipation or straining. Small perforations can result, leading to pain, nausea and vomiting, and fever. This is called diverticulitis. But radiation doesn’t cause the diverticula nor typical diverticulitis.

Keith Roach