The Top 10 Drugs -- 1997

Alan Cook, DC, practices in Eureka, California. He teaches the postgraduate seminars "How to Win the Argument with an MD," and "Osteoporosis," sponsored by Life University and several state chiropractic associations.

Chiropractors are typically insulated from the highly competitive world of the pharmacy industry. As a profession, we do not participate in the writing of the many millions of prescriptions filled annually in the U.S. It is remarkable to realize that the top 10 drugs are credited with 272,977,000 purchases (1997).¹

In the automotive industry, there are several broad classifications: sports utility vehicles, compact, mid-size, etc. Ford, GM, and Toyota all have their vehicles for each category. The numerous manufacturers, with copious advertisements, work hard for your attention and hopeful purchase. The same frame of reference exists in the pharmaceutical industry. The classifications of drugs include antibiotics, antidepressants, antihypertensives, cholesterol-lowering agents, analgesics, etc. The various manufacturers all have their product(s) in these categories. Competition is fierce. Marketing programs are varied and well funded. Full page advertisements are found in essentially every medical journal. Drug company representatives visit medical offices routinely to drop off samples, literature, and dinner invitations. Speakers are paid to lecture at hospital education sessions. Also, there are expanding efforts in advertising directly to the public.

Like the auto makers, the drug companies track product sales (their own and competing products) These data are instrumental in planning future marketing programs.

The following list of the top 10 drugs are for combined new and refill prescriptions. This listing includes eight drug classes and is an indication of the broad drug market as many of the top 200 drugs are simply a product that is competing with these top 10. Learning about these drugs will give you an insight into a large percentage of all drug sales and acquaint you with what the consuming American public is purchasing.

Additionally, the list of top 10 drugs for "new prescriptions" is found below. This list is largely germane to acute illness whereas the "total prescription" list relates to both acute and chronic illness.

1. Trimox antibiotic Apothecon
2. Premarin Tabs estrogen replacement Wyeth-Ayerst
3. Synthroid thyroid replacement Knoll
4. Hydrocodone/APAP analgesic Watson
5. Prozac antidepressant Dista
6. Lanoxin digitalis preparation Glaxo Wellcome
7. Prilosec proton pump Astra Merck
8. Vasotec antihypertensive Merck
9. Zithromax antibiotic Pfizer Labs
10. Norvasc antihypertensive Pfizer Labs

The number one drug in total prescriptions and 7 out of 10 in the new prescription list belongs to the antibiotic class of drugs. This class represents 12-14% of all prescribed drugs1. Use among children younger than 15 years was approximately three times as high as in any other age
group.²

Widespread use of antibiotics persist in spite of objections to the practice,³ the well demonstrated lack of efficacy,^4,5,6 and growing concerns about bacterial resistance to antibiotics.^7,8 This remarkable use and abuse of antibiotics is out of step with the science of our day. Reasons speculated for this are found in a profound letter to the editors of the journal Lancet:⁹

1. Erroneous physician beliefs.
2. Patient demands for antibiotics.
3. Pressure on physicians to limit appointment times.
4. The prescription is the path of least resistance.

Premarin has become almost synonymous with "estrogen replacement therapy" or "ERT." ERT is recommended almost universally to women at the perimenopause or postmenopausal time. The three reasons given for this widespread use of ERT are: relief of perimenopausal symptoms (hot flashes, night sweats, etc.); protection against osteoporosis; and protection against cardiovascular disease.

The manufacturers of Premarin, Wyeth-Ayerst, have begun marketing another estrogen hormone drug, Prempro. Unlike Premarin, Prempro contains both an estrogen fraction and a progestin (synthetic progesterone) fraction. Prempro was the #22 drug on the total prescription list in 1997.¹ Combining the sales of Premarin and Prempro would overtake Trimox as the #1 drug.

The major objection to ERT is the association with an increase in the risk of breast cancer. This issue has been clouded by controversy. However, the study with the greatest weight of evidence, the Nurses' Health Study,¹⁰ is difficult to ignore. The risks of breast cancer for those using ERT for five or more years were 32-71% greater than for women who had never used hormone replacement therapy.

Only recently have other risks associated with ERT come to light. These include: systemic lupus erythematosus;¹¹ thromboembolic events;^12-14 and fatal ovarian cancer.¹⁵ These three risks associated with ERT have received far less attention than the issue of breast cancer.

Synthroid

Synthroid is similar in chemical composition to L-thyroxine (or T4) as is produced and secreted by the thyroid gland. Synthroid is used as thyroid hormone replacement therapy for anyone with decreased thyroid function. Thyroid levels need to be monitored via lab tests and dosage needs tend to decrease with age.

A recent study performed at the University of California at San Francisco found no advantage to the use of Synthroid when compared to less expensive generic drugs. Unfortunately, the manufacturer of Synthroid, Knoll, used some strong arm tactics to suppress the publication of this research.¹⁶

Hydrocodone/APAP

This drug is a narcotic analgesic with acetaminophen (the active ingredient in Tylenol). Hydrocodone/APAP, along with nonsteroidal antiinflammatory drugs, is a first line medical therapy for musculoskeletal conditions that cause pain. Common side effects include: constipation; light-headedness; dizziness; drowsiness; stomach upset; and nausea, or flushing. These side effects are more attributable to the narcotic rather than the acetaminophen.

Prozac

Prozac is an antidepressant drug whose action is to inhibit the uptake of serotonin in the central nervous system. The two most common reasons for prescribing these selective serotonin reuptake inhibitors (SSRIs) are depression and obsessive-compulsive disorder. Numerous adverse reactions to these drugs have been reported. These include: anxiety; nervousness; insomnia; drowsiness; fatigue; tremors; GI complaints; dizziness; and increased appetite.

Lanoxin

Lanoxin is a digitalis preparation, originally extracted from the foxglove plant. It contains cardiac glycosides that act to increase the force and velocity of the heart muscle's contractions. Digitalis compounds are used to treat congestive heart failure and/or arrhythmias and are commonly prescribed with other drugs such as diuretics.

Prilosec

Prilosec was the first proton pump inhibitor. The pump inhibitors are regarded as more effective than the older histamine H2 receptor antagonist; a class of drugs whose action is to depress the production of the stomach's production of hydrochloric acid (e.g., Zantac, Tagament). Prilosec is used to treat heartburn, gastric ulcer and duodenal ulcer. Prolonged use of this class of drugs has been shown to induce liver damage.

Vasotec

Vasotec is the most prescribed member of the angiotensin converting enzyme (ACE) inhibitors. Conversion of angiotensin I to angiotensin II is one of the regulatory mechanisms for blood pressure. Vasotec is prescribed for people with hypertension and/or congestive heart failure. Patients taking this drug must be monitored for adverse effects to the white blood cell count and for proteinuria. It can also induce birth defects, liver failure and kidney dysfunction.

Norvasc

Norvasc is a calcium channel blocker that is prescribed for the treatment of hypertension and angina. Norvasc has been heavily marketed to replace an older calcium channel blocker, Procardia XL. Procardia XL, formerly among the top 10 drugs, received numerous bad press reports. Time will tell if the same negative findings attributed to Procardia XL will be true of Norvasc.

The top 10 drugs of 1997 (new and refills) represents more than 270,000,000 prescriptions filled in the United States and expenditures of over $73 billion.18 (This does not include the over-the-counter market.) The total spent on chiropractic care (1993) was $14 billion.¹⁹ The above costs do not factor in iatrogenic hospitalizations, morbidity, or mortality. The estimated annual expense directly attributable to drug reactions is $76.6 billion (1992).¹⁸

The pharmaceutical industry accounts for enormous health care expenses. Far too many of their products are overhyped, overpriced, and overused.

References

1. The top 200 drugs. American Druggist Feb 1998:46-53.
2. Jernigan DB, Cetron MS, Breiman RF. Minimizing the impact of drug-resistant streptococcus pneumoniae (DRSP). JAMA 1996;275:206-9.
3. Mainous III AG, Hueston WJ, Clark JR. Antibiotics and upper respiratory infection. J Fam Pract 1996;42:357-61.
4. Van Buchem FL, Dunk JHM, Van't Hoff MA. Therapy of otitis media: myringotomy, antibiotics, or neither? Lancet October 24, 1981:883-7.
5. Williams RL, et al. Use of antibiotics in preventing recurrent acute otitis media and treating otitis media with effusion. JAMA 1993;270:1344-51.
6. Orr PH, et al. Randomized placebo-controlled trials of antibiotics for acute bronchitis: a critical review of the literature. J Fam Pract 1993;36:507-12.
7. Breiman RF, et al. Emergence of drug-resistant pneumococcal infections in the United States. JAMA 1994;271:1831-5.
8. Hofmann J, et al. The prevalence of drug-resistant streptococcus pneumoniae in Atlanta. N Engl J Med 1995;333:481-6.
9. Gonzales R, Sande M. What will it take to stop physicians from prescribing antibiotics? (letter) Lancet 1995;345:665-6.
10. Colditz GA, et al. The use of estrogens and progestins and the risk of breast cancer in postmenopausal women. N Engl J Med 1995;332:1589-93.
11. Sanchez-Guerrero J, et al. Postmenopausal estrogen therapy and the risk for developing systemic lupus erythematosus. Ann Int Med 1995;122:430-3.
12. Daly E, Vessey MP, Hawkins MM, et al. Risk of venous thromboembolism in users of hormone replacement therapy. Lancet 1996;348:977-80.
13. Jick H, Derby LE, Myers MW, et al. Risk of hospital admission for idiopathic venous thromboembolism among users of postmenopausal estrogens. Lancet 1996;348:981-3.
14. Grodstein F, Stampfer MJ, Goldhaber SZ, et al. Prospective study of exogenous hormones and risk of pulmonary embolism in women. Lancet 1996;348:983-7.
15. Rodriguez C, Calle EE, Coates RJ, et al. Estrogen replacement therapy and fatal ovarian cancer. Am J Epidemiol 1995;141:828-35.
16. Wolfe SM. So much for impartial scientific research. Health Letter;12(6):12.
17. Furberg CD, Psaty BM, Meter JV. Nifedipine; dose-related increase in mortality in patients with coronary heart disease. Circulation 1995;92:1326-31.
18. Johnson JA, Bootman JL. Drug-related morbidity and mortality. Arch Int Med 1995;155:1949-56.
19. Health Care Financing Review. Department of Commerce, Fall 1995;17.