Why you've never heard of the most commonly prescribed drugs in the US

The number of drugs listed in short supply has tripled over the past five years, to a record 211 medications last year. (AP)

Pharmaceuticals are big business in the United States—in 2013 alone, spending reached $329 billion—but the driving force isn’t common medications. In fact, none of the 25 most commonly prescribed medications even crack the top 25 highest-grossing drugs. That’s because the highest-grossing drugs are all name brands, and the most commonly prescribed drugs are generics.

When possible, many doctors will prescribe generic drugs so that their patients can afford the medications they need. This is important because the high cost of drugs is a common reason patients decide not to take medications, even though proper adherence to many drugs can add years to a patient’s life. Generic drugs are cheaper because the companies manufacturing them don’t have to pay for research, patents or advertising. The reason not all drugs have generic versions is because the company that invents the drug and sells it under a brand name has exclusivity to sell it for three to seven years.

READ MORE: Common Drug Myths Debunked

The top drugs

The most common prescriptions are for antihypertensives, or blood pressure medications, accounting for 698 million prescriptions in 2013. Mental health drugs were next with 519 million scripts, while pain medications accounted for 477 million.

Below are the top five dispensed individual prescription drugs:

1. Hydrocodone/acetaminophen is the most popular narcotic painkiller in the nation, and is the generic version of Vicodin. It is usually indicated for moderate to severe pain, and can be addictive.

2. Levothyroxine is a synthetic thyroid hormone that is usually prescribed to treat hypothyroidism. Sometimes it is prescribed off-label for other thyroid disorders, such as enlarged thyroid and thyroid cancer.

3. Lisinopril is used to treat high blood pressure. It is in the class of medications known as ACE inhibitors, which help blood flow through the vessels more smoothly.

4. Metoprolol is also used to treat high blood pressure, as well as angina, and to improve chances of survival after a heart attack. Metoprolol is a beta blocker, and works by relaxing blood vessels in slowing heart rate to reduce blood pressure.

5. Simvastatin is used to treat high levels of “bad” LDL cholesterol and to increase “good” HDL cholesterol. It is a statin, a class of drugs that works by reducing the body’s production of cholesterol to decrease buildup.

How to save

Since these commonly prescribed drugs are generic, they do not cost as much as their brand-name counterparts. And since generic drugs are the same as brand-name versions in every way except appearance and inactive ingredients, there’s no reason to pay more for them. In fact, prices can vary between these generics and branded versions by a factor of tenfold for one month’s supply.

For example, 30 tablets of the lowest dose of simvastatin will run you about $9 at a CVS pharmacy in San Francisco, but if you opt for brand-name Zocor, you’ll pay roughly $93 at the same pharmacy. In the case of metoprolol and Lopressor, the price difference is even larger: $8 versus $124 for 60 tablets the same 50-mg dosage. In fact, generics are cheaper by 80%-85% on average, according to the Food and Drug Administration, so ask your doctor if generics are available for any of your prescriptions.

Even if you can’t take a generic, there are other ways you can save on your prescriptions. Check websites like GoodRX or LowestMed to determine which pharmacy near you has the lowest prices, or opt for a mail-order pharmacy for even more savings. Ask your doctor if she has any free samples on hand before filling a new prescription, or if you can save money by pill splitting. Finally, low-income individuals may qualify for government assistance or a patient assistance program offered by the company that makes the drug.

Lacie Glover writes for NerdWallet Health, a website that empowers consumers to find high quality, affordable health care and insurance.