Is newer always better? For example, why do new drugs replace older ones? Newer drugs are rarely tested against older drugs in clinical trials, so there's usually no comparison information available. How can doctors tell if an emerging drug is better than those already available? Often they can't. But there are always drug company sales representatives ready to help, promoting the merits of the newer drugs. They can be quite persuasive. And many doctors operate on the assumption that a newer drug must be a better drug. So newer drugs often prevail.
In 2002, a month's supply of diuretics cost between $2 and $3. A month's supply of two newer drugs, beta-blockers and ACE inhibitors, cost about $48 and $43, respectively. Depending on the exact drugs involved, switching to a diuretic could save a patient between $250 and $650 a year.
Sometimes there is good evidence on how medications compare to each other. The ALLHAT trial from 2002 was an eight-year study comparing the cost and effectiveness of different types of blood pressure medications. It found that an older type of medication, called a thiazide diuretic (water pill), was generally as effective as newer blood pressure medications and at a fraction of the cost. In 2002, a month's supply of diuretics cost between $2 and $3. A month's supply of two newer drugs, beta-blockers and ACE inhibitors, cost about $48 and $43, respectively.
Depending on the exact drugs involved, switching to a diuretic could save a patient between $250 and $650 a year.
But the ALLHAT study doesn't seem to have had much of an effect on doctors' prescribing practices. Prescription of diuretics had been declining for some time. In 1982, they represented about 56% of the prescriptions written for high blood pressure. By 1992, they had declined to about 27%, and this trend has continued.
Barry Davis MD, PhD, the Guy S. Parcel Chair in Public Health at the University of Texas School of Public Health, was one of the researchers on the ALLHAT trial. A few years ago, Davis and other doctors from the trial received a $4 million grant from NIH to travel the country and explain the benefits of prescribing diuretics to other doctors in small group meetings. This type of practice is called academic detailing. It's not very common because there's rarely any money to support it.
After two years on the road, this program, called the ALLHAT Dissemination Project (ADP), seems to be having an effect.
ADP reached out to over 18,000 doctors in 1700 different locations in the 2+ years of its existence, before its end in 2007. Pharmacy records from the counties it visited showed an 8.7% rise in thiazide-type diuretic prescriptions, compared to a 3.9% rise in counties it did not visit. In other words, over twice as many new diuretic prescriptions were filled in the counties they visited. By comparison, from 2004-2008, national diuretic use did not increase at all.
Academic detailing influences doctors to prescribe drugs based on their known effectiveness and cost. What would prescription practices be like if academic detailing was more common? It's impossible to tell because right now, that's just not how the system works. But Davis' results suggest that more academic detailing would change the way doctors prescribe medications to their patients.
An article on the effects of the ALLHAT Dissemination Project was published in the May 24, 2010 issue of Archives of Internal Medicine.