The Top 10 drugs in America: A closer look at their implications in dentistry

A closer look at their implications in dentistry

By Lisa Dowst-Mayo, RDH, BSDH

Prescription drug sales in the United States are big business. People in the United States spend billions of dollars annually on prescription medications-in 2012, for example, Americans spent $326 billion to be exact!1 Prescription drug sales account for 11% of overall U.S. health-care expenditures.¹

When I was in private practice, it was common for me to have to look up at least two or three medications every day before seating a patient so that I would be aware of their uses and if there were any oral considerations. As a pharmacology instructor, I am all too familiar with how frequently medications on the market change, and how difficult it is to stay current in the field of pharmacology. Staying current with medications is imperative for the private practitioner, as many medications have interactions with the medicaments administered in a dental environment. Of particular concern is the use of vasoconstrictors in local anesthetic. There are many prescription medications and medical conditions that can either restrict or prohibit the use of vasoconstrictors. This article will present the most commonly prescribed medications in the U.S. market, discuss the drugs' mechanism of action, what conditions they are commonly used to treat, and if those drugs have interactions with dental local anesthetic.

Future U.S. drug spending is expected to increase with the number of citizens (approximately 14 million by 2016) who will gain health insurance through the Affordable Care Act (ACA).¹ This nationwide increase in drug spending is due to many factors such as greater access to drugs, an increase in the aging population, the use of new and more expensive medications, and the availability of less expensive generic products.¹ According to the Centers for Disease Control and Prevention (CDC), in the next 25 years, the U.S. population over the age of 65 will double, and "by the year 2023, older adults will account for roughly 20% of the U.S. population."² This population subgroup presents with many health challenges for providers because they generally have more than one chronic health condition that is being treated with medication.²

The moneymakers

According to the IMS National Prescription Audit, as cited by Schumock et al., in 2014, the most commonly prescribed medication was levothyroxine (Synthroid) at 23 million prescriptions. Levothyroxine is used in the treatment of underactive thyroid.^3,4 The 10 most common prescription medications in the United States are listed in Table 1.1 The medications with the highest profitable sales revenues in 2014 are listed in Table 2.1 The most profitable prescription medication was aripiprazole (Abilify) at $6.9 billion gross for the second year in a row.¹ The tenth most producing was pegfilgrastim (Neulasta), which grossed $3.3 billion.¹

None of these statistics surprised me, and I'm sure they do not surprise you either. Given the "super-size-me" diet of many Americans, coupled with sedentary lifestyles, it makes sense why four of the top 10 drugs sold in the United States are used in the treatment of gastroesophageal reflux disease (GERD), high cholesterol, hyperlipidemia, high blood pressure, and diabetes.

Esomeprazole-Esomeprazole (Nexium) is a proton-pump inhibitor (PPI) that is commonly recommended after H2-blockers such as cimetidine (Tagamet) or ranitidine (Zantac) have failed to control symptoms.³ PPIs achieve almost total suppression of acid secretion because they bind irreversibly to parietal cells that line the stomach and reduce the peak acid output.³ Esomeprazole is now sold over the counter and can also be prescribed if higher doses are indicated.³

Rosuvastatin-Rosuvastatin (Crestor) is used for the treatment of high cholesterol and hyperlipidemia.³ It is in the drug class known as 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors; these are more commonly referred to as "statins" because the generic name of these drugs ends in that suffix.³ Because statins are metabolized by a specific enzyme system in the liver, they have many drug interactions.³ Erythromycin, clarithromycin, and grapefruit juice inhibit the liver enzyme that metabolizes statins.³ This action can produce toxic levels of the statin in the body.³ Statins lower LDL (low-density lipoproteins) and VLDL (very-low-level lipoproteins), and they increase HDL (high-density lipoproteins). LDL and VLDL are the "bad" cholesterols because they transport cholesterol to damaged areas in arteries and aid in the formation of plaques.³ HDL cholesterol is known as the "good" or "protective" cholesterol because it goes looking for deposited cholesterol to return to the liver for disposal.³ Statins, as a group, are very effective for many patients in controlling high cholesterol and lipid levels, and are usually one of the first-line treatment drugs.³

Valsartan-Valsartan (Diovan) is in the drug class known as angiotensin receptor blockers (ARBs).^3,4 ARBs are effective blood pressure reducers. They interfere with the body's renin-angiotensin-aldosterone (RAA) mechanism.³ ARBs block angiotensin II from being released, and stop the actions of the RAA mechanism,³ which is activated when systemic blood pressure drops. This is one of the body's ways of maintaining homeostasis. The release of angiotensin II causes three actions to occur in the body, all of which are the body's normal function of maintaining normal blood pressure and blood volume.³

In hypertension, the RAA mechanism can be overstimulated, which causes persistent high systemic blood pressure.³ By stopping the release of angiotensin II, ARBs prevent the body from raising systemic blood pressure by producing vasodilation and increasing the excretion of sodium and water. All generic ARB drugs end in the same suffix (-artan), so they are easy for professionals to identify.

Insulin glargine-Insulin glargine (Lantus) is mainly used in the treatment of Type I diabetes.^3,4 Insulin glargine is a long-acting medication that is administered by subcutaneous injection.³ Type I diabetes accounts for only 5% of all diabetes cases in the U.S.⁵ Insulins can also be used in the treatment of Type II diabetes when other methods (e.g., lifestyle changes, oral medications) have failed to control blood glucose levels.^3,4 Twenty-nine million (1 in 11) people are currently diagnosed with diabetes in the United States.⁵ Sixty-eight million (1 in 3) people are said to have prediabetes, and nine out of 10 do not know they have prediabetes.⁵ The dental provider will surely treat patients with diabetes multiple times in a month, and will need to be familiar with the varying treatment modalities based on these nationwide statistics. Currently, in the United States, one in three adults is predicted to develop Type II diabetes at some point in their lifetime, and more than 5,000 youths have been diagnosed with Type II diabetes each year since 2008.⁵

Albuterol and fluticasone/salmeterol-Two drugs in the top 10 (see Table 1) are used in the treatment of respiratory diseases. The CDC reports that 17.8% of Americans currently smoke.⁶ That accounts for 1 in 5 people, or nearly 18 out of every 100 adults.⁶ It is well established in the literature that smoking is a contributing factor to both asthma symptoms and the development of COPD (chronic obstructive pulmonary disease). Albuterol (Ventolin) and fluticasone/salmeterol (Advair Diskus) are useful in the management of asthma and COPD.⁶ Both are dispensed as inhalers; albuterol can also be administered by tablet form.³ Advair is a combination bronchodilator and anti-inflammatory steroid.³ Albuterol is a selective beta-2 agonist that leads to bronchodilation and relaxation of bronchial smooth muscle.^3,4 Albuterol is traditionally considered a rescue drug and indicated for use when a patient is having an acute respiratory attack.^3,4 The combination of fluticasone/salmeterol is considered a maintenance medication for daily use.^3,4 Dental professionals should advise patients who use these medications to rinse their mouths or brush their teeth after administration due to the risk of candidiasis development.⁴

Psychiatric medications-The highest profitable drug sold in the U.S. to date is aripiprazole (Abilify). Aripiprazole is an atypical antipsychotic and is typically used in the treatment of varying psychotic disorders.^1,3,4 Duloxetine (Cymbalta) is the sixth most commonly prescribed medication in the United States (see Table 1), and is a selective serotonin norepinephrine reuptake inhibitor (SNRI).^1,3,4 SNRIs are in the antidepressant class of drugs whose action is to increase serotonin and norepinephrine by blocking the reuptake in the synaptic gap.³ This allows serotonin and norepinephrine to be more readily available for use in the body. Aripiprazole's action is as a dopamine and serotonin blocker.³ Atypical antipsychotics, as a class, cause fewer undesirable side effects than earlier drugs such as the typical/conventional antipsychotics (e.g., phenothiazides).³ Atypical drugs such as aripiprazole cause fewer anticholinergic effects (e.g., dry mouth, blurred vision, tachycardia, sexual dysfunction, constipation, urinary retention) and fewer antihistaminic effects (e.g., sedation, drowsiness, weight gain).³

Lisdexamfetamine dimesylate (Vyvanse) is a central nervous system stimulant used as a treatment modality for attention deficit hyperactivity disorder (ADHD).³ It is a Schedule II drug, which can lead to addiction and tolerance.^3,4 Currently, 5-8% of children in the United States are diagnosed with ADHD.⁷ According to the CDC, fewer than one in three children with ADHD receive both medication treatment and behavior therapy.⁷ Behavior therapy is now recommended as the first-line treatment for this group, and only half of preschool children are receiving this needed treatment.⁷ One in four children are only treated with medication, which is not recommended by leading professionals.⁷ Vyvanse is a psychomotor stimulant that increases the activity of norepinephrine and dopamine in the brain.³ It can either inhibit the reuptake of both neurotransmitters in the synaptic gap, or stimulate the release of both from nerve endings.³ This action will increase alertness and attention span in children with ADHD, and also calms down their hyperactivity as a paradoxical effect.³

Pregabalin-Rounding out the top 10 medications is pregabalin (Lyrica), which is advertised in the treatment for fibromyalgia, diabetic-associated neuropathic pain, or as an adjunct therapy for adults with partial onset seizures.⁸ Lyrica is a GABA enhancer.⁸ GABA is an inhibitory neurotransmitter which keeps nerves in a hyperpolarized state.^3,4 This makes it more difficult for an action potential to potentiate without a very powerful stimulus. To put it another way, Lyrica "calms" nerves and makes it more difficult for them to become stimulated and cause pain.

Dental vasoconstrictor considerations

Dental providers should administer vasoconstrictors (epinephrine, levonordefrin) with caution when a patient is taking duloxetine or many other antidepressant drugs such as tricyclic antidepressants (TCAs; Elavil), SNRIs (Cymbalta, Effexor), monoamine oxidase inhibitors (MAOIs; Marplan), and atypical antidepressants (Wellbutrin)^3,4 (see Table 3). The only class of antidepressant drugs where vasoconstrictors are not considered dangerous for use is the SSRIs (e.g., Celexa, Lexapro, Prozac, Luvox, Paxil, Zoloft).⁴

Vasoconstrictors should also be used with caution or avoided in any patient with a preexisting heart condition, such as uncontrolled hypertension, congestive heart failure, angina, or arrhythmias.⁴ Any patient on cardiac medications should be questioned as to the stability of their condition, and depending on their answer, dental providers should consider using vasoconstrictor-free anesthetic or using a cardiac dose of vasoconstrictors (i.e., two carpules).

Vasoconstrictors can also be contraindicated in patients with asthma.⁴ Asthmatics can have a sensitivity or allergy to sulfite, which is used in dental local anesthetic to preserve the vasoconstrictor.⁴ Vasoconstrictor-free anesthetic solutions are advised when treating a patient with a known sulfite allergy.

No special consideration for the use of vasoconstrictors is indicated in patients taking levothyroxine for an underactive thyroid.⁴ Patients with hyperthyroidism should not receive dental hygiene care until they are well controlled because they are likely to develop hypertension and arrhythmias.⁴ Vasoconstrictors would be contraindicated for patients with hyperthyroidism, but not hypothyroidism.⁴

Well-controlled diabetic patients can safely receive dental local anesthetic with vasoconstrictors.⁴ Patients who are not well controlled should have the amount of vasoconstrictors limited to a cardiac dose (i.e., two carpules).⁴

Prescription drug use in the United States is unlikely to decrease in the years to come with the expansion to health services allotted by the ACA and the aging population rates. Dental professionals need to take an active role in staying current with market drug changes so they are aware of any contraindications for care. Being familiar with the top 10 most commonly prescribed medications in the United States will arm the dental professional with essential drug knowledge needed in the treatment of many of their patients. RDH

Lisa Dowst-Mayo, RDH, BSDH, graduated magna cum laude with a degree in dental hygiene sciences from Baylor College of Dentistry in 2002. She is currently pursuing a Master in Healthcare Administration from Ohio University. She is a full-time professor at Concorde Career College in the dental hygiene department where she teaches pharmacology, clinical sciences, board review, and special needs. She is a current board member of the Dallas Dental Hygiene Society and is a published author and national speaker. She can be contacted through her website at www.lisamayordh.com.

References

1. Schumock, GT, Li EC, Suda KJ, et al. National trends in prescription drug expenditures and projection for 2014. American J Health Syst Pharm. 2014;71(6):482-499.
2. Centers for Disease Control and Prevention (CDC). The State of Aging and Health in America 2013. Atlanta, GA: Centers for Disease Control and Prevention, US Department of Health and Human Services; 2013. http://www.cdc.gov/aging/pdf/state-aging-health-in-america-2013.pdf.
3. Hinter H, Nagle B. Pharmacology: An Introduction. 6th ed. New York: McGraw-Hill Education; 2011.
4. Weinberg MA, Theile CW, Fine JB. Oral Pharmacology for the Dental Hygienist. 2nd ed. Upper Saddle River, New Jersey: Pearson; 2013.
5. Centers for Disease Control and Prevention. A Snapshot: Diabetes in the United States. CDC website. http://www.cdc.gov/diabetes/pubs/statsreport14/diabetes-infographic.pdf. Accessed November 30, 2015.
6. Centers for Disease Control and Prevention. Current Cigarette Smoking Among Adults in the United States. CDC website. http://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm#national. Updated August 25, 2015. Accessed November 30, 2015.
7. Centers for Disease Control and Prevention. Attention-Deficit/Hyperactivity Disorder (ADHD): Data & Statistics. http://www.cdc.gov/ncbddd/adhd/data.html. Updated July 8, 2015. Accessed November 30, 2015. 8. Lyrica (pregabalin) - Drug Summary. PDR.net. http://www.pdr.net/drug-summary/lyrica?druglabelid=467&id=1093. Accessed November 30, 2015.