Top 200 Drugs of 2018: Which Ones Are Making an Impact?

The ClinCalc DrugStats Top 200 Drugs of 2018 list was released this month.¹ The data populating this list are produced by aggregating U.S. survey data from the Medical Expenditure Panel Survey. The 2018 DrugStats database includes outpatient prescription data from January through December 2015 and provides a rank for each medication based on the number of prescriptions. For example, the DrugStats No. 1 ranked medication, lisinopril, is the most commonly prescribed medication and has retained this title for the past 4 years. Although there are a number of interesting trends in the new data, there are 4 drug classes demonstrating rapid changes in the market.

SGLT2 Inhibitors (Gliflozins)

Sodium-glucose cotransporter 2 (SGLT2) inhibitors, or gliflozins, are relatively new to the market, with the first medication in this class (canagliflozin, Invokana) obtaining FDA approval in 2013. In 2014, canagliflozin ranked 324, with just over 1 million prescriptions, but in the most recent 2015 data set, it moved up to 162, with more than 4 million prescriptions.

The other SGLT2 inhibitors are newer to the market and did not have data in last year’s DrugStats list. Dapagliflozin (Farxiga), the second agent to the market, ranked 276, with just over 1.5 million prescriptions in 2015. Empagliflozin, an SGLT2 inhibitor that made a huge splash with its EMPA-REG OUTCOME trial at the end of 2015, does not yet have prescription data usage for comparison.²

Direct-Acting Oral Anticoagulants (DOACs)

DOACs have been on the market since dabigatran’s (Pradaxa) FDA approval in 2010. Since that time, several other agents have been approved for a variety of indications, from the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation to venous thromboembolism treatment.

Despite being the first to the market and having an FDA-approved reversal agent (idarucizumab, Praxbind), dabigatran’s hold on the market is starting to dwindle. Between 2014 and 2015, prescriptions for dabigatran decreased from about 3.3 million to 2.7 million, and its ranking fell from 188 to 209, losing its position in the 2018 Top 200 Drugs list.

By contrast, both rivaroxaban (Xarelto) and apixaban (Eliquis) have made large gains in prescribing metrics. For 2015, rivaroxaban recorded about 5.5 million prescriptions and rose in the rankings from 174 to 131, making it the most commonly prescribed DOAC based on the DrugStats data set. Apixaban made similar gains, moving into the Top 200 Drugs list with a ranking of 185, up from 308 in 2014 and about 3.3 million prescriptions in 2015.

Newer DOAC agents to the market, including betrixaban (Bevyxxa) and edoxaban (Savaysa), did not have sufficient data to make the 2018 DrugStats list.

DPP-4 Inhibitors (Gliptins)

Dipeptidyl peptidase (DPP) 4 inhibitor, or gliptins, are oral medications used to improve glycemic control in type 2 diabetes mellitus. The first agent, sitagliptin (Januvia) was approved in 2006 and has consistently retained the bulk of the market share within this drug class. Prescriptions for sitagliptin have continued to increase as demonstrated by its ranking rising to 106 from 90.

Linagliptin (Tradjenta) is making large strides as the second-most commonly prescribed DPP-4 inhibitor. From 2014 to 2015, it moved from rank 299 to 218, just missing a position in the 2018 Top 200 Drugs list. During the same period, linagliptin prescriptions nearly doubled to about 2.6 million in 2015 from about 1.4 million in 2014. The increase in linagliptin prescriptions is likely multifactorial, though its absence of a renal dose adjustment is an attractive factor, particularly in a patient population in which renal impairment is common.³

Although there are other DPP-4 inhibitors on the market, their use is either declining or is too uncommon to be detected within the survey data.

HMG-CoA Reductase Inhibitors (Statins)

The statin drug class is quite aged compared with the previously described drug classes. The first statin approved by the FDA was lovastatin in 1987. Since then, a number of different statins have been approved for a variety of indications predominantly focused on reducing LDL cholesterol and reducing the risk of atherosclerotic cardiovascular disease events. Given the age of the statin drug class, it is no surprise that statins are very commonly prescribed. In fact, there are 5 statins that have a ranking above 100 on the 2018 DrugStats list.

For the first time, atorvastatin (Lipitor) has overtaken simvastatin (Zocor) in terms of total prescriptions. Simvastatin usage has been declining since 2011 from a peak of about 107 million prescriptions down to 74 million in 2015. This decline was at least in part due to the 2011 FDA Drug Safety Communication regarding simvastatin dose maximums, drug interactions, and risk of rhabdomyolysis.⁴ By contrast, atorvastatin has been gaining ground since 2011, rising from about 46 million prescriptions to 93 million in 2015. This increase moved atorvastatin from a rank of 5 to 3, making it the third-most commonly prescribed medication in 2015, behind lisinopril and levothyroxine.

References

1. ClinCalc.com. ClinCalc DrugStats database. clincalc.com/DrugStats. Accessed February 17, 2018.

2. Zinman B, Wanner C, Lachin JM, et al. Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. N Engl J Med. 2015;373(22):2117-28. doi: 10.1056/NEJMoa1504720.

3. Tradjenta [prescribing information]. Ridgefield, CT: Boehringer Ingelheim Pharmaceuticals, Inc; 2017.accessdata.fda.gov/drugsatfda_docs/label/2012/201280s005lbl.pdf. Accessed February 23, 2018.

4. FDA. FDA drug safety communication: new restrictions, contraindications, and dose limitations for Zocor (simvastatin) to reduce the risk of muscle injury. fda.gov/Drugs/DrugSafety/ucm256581.htm. Updated December 15, 2017. Accessed February 17, 2018.