Each January hundreds of faxes arrive in primary care doctor’s offices because of formulary changes that dictate what types of medicines are preferred based on a patient’s drug coverage plan.

The list of covered prescription medications changes annually and sometimes that leaves people guessing about their copay when they arrive at the pharmacy for the first time in the calendar year.

I’m sure I’m not alone in dreading this tsunami of paperwork that descends each time the medications change, without much of a warning, except for the empty paper tray in the fax machine that the beeps waring us of the coming storm.

But recently, two major pharmaceutical benefit plans released their lists, and this time I’ll be prepared for January.

CVS Caremark and ExpressScripts, two of the largest nationwide programs, have released their list of soon-to-be-excluded medications along with what they have determined are alternatives that can be substituted.

I’m not a fan of insurance plans telling me what to prescribe, but for once I think they’re actually making a lot of sense.

Going down the list of asthma medications, for example, the drugs of choice from Caremark are Advair or Dulera. The excluded medicine is Symbicort. Although at first glance that’s limiting options, there are still two pharmacologically similar medications that are clinically interchangeable.

Patients often get upset if the color or size of their medication changes, but in many cases, if the generic version is available, it just makes sense to purchase that medicine rather than paying extra for a brand name.

Now, it doesn’t mean that it’s impossible to get Symbicort prescribed, just that in order to get it covered by the insurance carrier, patients have to at least have tried the other two options. Extra work? Yes. But potentially life threatening? No. In fact, these particular medicines haven’t changed status for the past three years for Caremark.

Express Scripts has a shorter list of excluded drugs, but also provides a list of alternatives. For the diabetes category, out of five different types of DPP-4 — a newer generation of diabetes pills designed to help lower blood sugar — two are covered, three are not. But they all work the same way, with slight variations in numbers of pills taken in a day for those with kidney problems. But they are all in the same class of medications and even just having one option would be enough.

The idea behind having certain medications that are covered over others boils down to cost. For each drug class, certain pharmaceutical companies will offer discounts if market share is guaranteed. The easiest way to do this is to provide a limitation on other competing products for patients of a particular plan.

Patients often get upset if the color or size of their medication changes, but in many cases, if the generic version is available, it just makes sense to purchase that medicine rather than paying extra for a brand name.

The Food and Drug Administration has mandated that it is the same pharmacologically active substance in the same exact concentration and should treat the same condition with exactly the same results. For those who insist on taking the brand name, the added cost is up to them, which is only fair.

I’m not defending the pharmaceutical industry for charging such high prices, but I do see the rationale in limiting the numbers of the same types of pills that are provided for any given diagnosis. There’s no need for 10 statin medications to be available if there are only two basic differences between all of them.

Various companies make copycat medications as they rush to be second or third to market, trying to find a way to differentiate themselves among their competitors. But to have patients spend more to duplicate research and development that is already done in order to just have another version of the same choice just doesn’t make sense.

The money would be better spent elsewhere. If less formulary access means that there will be more money funneled into research and development of new drugs, it’s a win for everyone.

We need new medications to treat conditions like Alzheimer’s dementia, currently affecting one-third of the U.S. population above age 85.

We need new advances in the treatment of cancer, one of the leading causes of death worldwide.

The next superbug might be around the corner and we will need newer antibiotics for when we have overused the current ones and all the bacteria have become resistant.

We don’t need six types of insulin that all do the same thing.

Formularies for all of the different plans used to be a mystery, now they are posted online, almost six months before the changes take effect. I’m going to keep printed copies in my office and bookmark the websites that list the alternatives.

When January comes around, this time it’s going to be a lot easier to be prepared for the onslaught of faxes. Having informed patients will make this process a lot easier for all of us.