The best-selling brand-name drugs are not necessarily the most-prescribed medications in the United States.
 
IMS Health recently revealed the 50 most-prescribed brand-name drugs and the 50 best-selling brand-name drugs between April 2014 and March 2015.
 
Here are some noteworthy discrepancies between prescription drug sales and prescribing patterns for particular conditions:
 
1. Hepatitis C
Hepatitis C drugs sofosbuvir (Sovaldi) and sofosbuvir/ledipasvir (Harvoni) ranked 3rd and 6th on the list of top 50 brand-name drugs by sales, respectively, while simeprevir (Olysio) ranked 33rd.
 
Together, the 3 hepatitis C drugs generated more than $14 billion in sales between April 2014 and March 2015, though none of them appeared among the top 50 most-prescribed brand-name drugs.
 
This is likely due in large part to the fact that the 2 largest pharmacy benefit managers (PBMs) in the United States—Express Scripts and CVS Caremark—continue to exclude the specialty drugs amid a high-profile debate over their cost-benefit ratios. 

2. Contraceptives
Three different contraceptives—the Nuvaring, Lo Loestrin Fe, and Ortho Tri-Cyclen Lo 28—appeared among the top 50 brand-name drugs by prescriptions written, but no contraceptives at all appeared on the list of top 50 brand-name drugs by sales.
 
This could be attributed to the fact that private insurance companies had to start providing contraceptive at no charge beginning in August 2012 under the Affordable Care Act.
 
The appearance of any contraceptive on either list may be less likely as policy groups continue to push for OTC access to birth control. For example, pharmacists in Oregon will be soon authorized to dispense transdermal and oral contraceptives without a prescription to women 18 yearsor older.

3. Multiple Sclerosis
Five different multiple sclerosis (MS) drugs—glatiramer acetate (Copaxone), dimethyl fumarate (Tecfidera), natalizumab (Tysabri), fingolimod (Gilenya), and interferon beta-1a (Avonex)—appear among the top 50 best-selling brand-name drugs.
 
Nevertheless, none of these MS treatments made the 50 most-prescribed drugs list, let alone the top 100.
 
Ron Lanton III, Esq, recently wrote that manufacturers price these specialty drugs high because they are seen as “high-value transformative medications that are just shy of being called curative” and represent a movement away from “me-too treatments” and “drugs that improve patient conditions to the point where they become manageable.”

Avonex is newly excluded from CVS’s formulary. 

4. Hypertension
Five different antihypertensive agents—nebivolol (Bystolic), valsartan (Diovan), olmesartan medoxomil (Benicar), olmesartan medoxomil/hydrochlorothiazide (Benicar HCT), and metoprolol succinate (Toprol XL)—are included on the list of the 50 most-prescribed brand-name drugs.
 
While none of these drugs made the 50 best-sellers list, all but Toprol XL appeared further down on the 100 best-sellers list.
 
Hypertension treatment recommendations have recently undergone significant changes, especially with the latest Joint National Committee (JNC 8) guidelines.
 
In addition, the FDA expanded the approval of Benicar in 2010 to treat the approximately 3.6 million hypertensive children in the United States, which could have increased the number of prescriptions written.

5. HIV
Three different HIV treatments appeared on the 50 best-selling brand-name drugs list: efavirenz/emtricitabine/tenofovir disoproxil fumarate (Atripla), emtricitabine/tenofovir disoproxil fumarate (Truvada), and elvitegravir/cobicistat/ emtricitabine/tenofovir (Stribild).
 
Together, these drugs generated more than $5.5 billion in sales between April 2014 and March 2015. However, none of these treatments appear on the 50 most-prescribed list, suggesting low patient access.
 
Notably, a mathematical model presented in 2012 forecasted that prescribing a generic version of Atripla could translate to savings between $200,000 and $1 billion for drug coverage providers in the first year of therapy.
 
Patents on Atripla continue until 2021.

6. Arthritis
Arthritis drugs spotted in the 50 best-selling list—adalimumab (Humira), etanercept (Enbrel), infliximab (Remicade), rituximab (Rituxan), and celecoxib (Celebrex)—generated combined sales of $24.3 billion between April 2014 and March 2015.
 
The US Centers for Disease Control and Prevention (CDC) estimates that 52.5 million US adults currently have arthritis, while 294,000 children under 18 have been diagnosed with arthritis or another rheumatic disease. 

7. Chronic Obstructive Pulmonary Disease
Three drugs indicated to treat chronic obstructive pulmonary disease (COPD)—fluticasone/salmeterol (Advair Diskus), tiotropium bromide inhalation powder (Spiriva HandiHaler), and budesonide/formoterol fumarate dihydrate (Symbicort) —together generated sales of $10.5 billion between April 2014 and March 2015.
 
Nearly 57 million prescriptions for these medications were dispensed in the same time period.
 
More than 15 million individuals in the United States have COPD, though the CDC estimates that more than 50% of adults with low pulmonary function are unaware that they have COPD—indicating that the incidence of COPD may actually be much higher. 

8. Cancer
Three different cancer drugs—bevacizumab (Avastin), imatinib mesylate (Gleevec), and trastuzumab (Herceptin)—have generated a combined $7.7 billion in sales between April 2014 and March 2015.
 
Avastin is indicated to treat metastatic colorectal cancer, while Gleevec is indicated to treat leukemia in both adult and pediatric patients, and Herceptin treats breast, stomach, and esophagus cancers.
 
According to Mel Seabright, PharmD, MBA, Gleevec costs just $159 per year to produce, yet US insurers pay $106,000 for a year’s worth of treatment.
 
“Of note, newer anticancer drugs are not associated with greater survival benefits compared with older drugs,” he wrote

Drugs Rank by Sales Rank by Presciptions
Hepatitis C
Harvoni #6 ($5.4 billion)
Sovaldi #3 ($7.0 billion)
Olysio #33 ($1.8 billion)
Contraceptives
Lo  Loestrin Fe #40 (3.3 million)
Nuvaring #29 (4.9 million)
Ortho-Tri-Cy- Lo 28 #46 (2.9 million)
Multiple Sclerosis    
Avonex #48 ($1.3 billion)
Copaxone #11 ($4.2 billion)
Gilenya #41 ($1.5 billion)
Tysabri #37 ($1.6 billion)
Tecfidera #18 ($3.1 billion)
Hypertension
Benicar #68 ($980.6 million) #32 (4.5 million)
Benicar HCT #90 ($760 million) #39 (3.3 million)
Bystolic #83 ($834.2 million) #20 (6.5 million)
Diovan #69 ($976.6 million) #26 (5.2 million)
Toprol-XL #49 (2.8 million)
HIV    
Atripla #19 ($3.0 billion) #94 (1.1 million)
Stribild #39 ($1.5 billion)
Truvada #21 ($2.6 billion) #75 (1.7 million)
Arthritis
Celebrex #31 ($1.9 billion) #21 (6.4 million)
Enbrel #5 ($6.0 billion)
Humira #1 ($8.3 billion)
Remicade #10 ($4.6 billion)
Rituxan #15 ($3.5 billion)
COPD
Advair Diskus #8 ($4.8 billion) #5 (13.8 million)
Combivent Respimat  #48 (2.8 million)
Spiriva HandiHaler #16 ($3.4 billion) #9 (9.6 million)
Symbicort #25 ($2.4 billion) #13 (8.3 million)
Cancer
Avastin #20 ($3.0 billion)
Gleevec #22 ($2.5 billion)
Herception #26 ($2.3 billion)