Page 1135 - Basic _ Clinical Pharmacology ( PDFDrive )

CHAPTER 63 Therapeutic & Toxic Potential of Over-the-Counter Agents 1121

array of products presented and will likely use those that are most agents could not be used safely and effectively in an OTC setting.
heavily advertised. The nonprescription drug advisory committee believed that
Since 1972, the US Food and Drug Administration (FDA) has diagnosis and ongoing management by a health care professional
been engaged in a methodical review of OTC ingredients for both was necessary for the management of hyperlipidemia, a chronic,
safety and efficacy. There have been two major outcomes of this asymptomatic condition with potentially life-threatening conse-
review: (1) Ingredients designated as ineffective or unsafe for their quences. In a similar recommendation, oral acyclovir for OTC
claimed therapeutic use are being eliminated from OTC product use in the treatment of recurrent genital herpes was not approved
formulations (eg, antimuscarinic agents have been eliminated because of concerns about misdiagnosis and inappropriate use
from OTC sleep aids; attapulgite and polycarbophil can no lon- leading to increased viral resistance.
ger be marketed as OTC antidiarrheal products); and (2) agents There are three reasons why it is essential for clinicians to
previously available by prescription only have been made available be familiar with the OTC class of products. First, many OTC
for OTC use because they were judged by the review panel to medications are effective in treating common ailments, and it
be generally safe and effective for consumer use without medical is important to be able to help the patient select a safe, effective
supervision (Table 63–1). The prescription-to-OTC switch pro- product. Because health care insurance practices encourage clini-
cess has significantly enhanced and expanded self-care options cians to reduce costs, many providers will recommend effective
for US consumers. More than 100 OTC active ingredients or OTC treatments, since these medications are rarely paid for by
dosages are on the market today that were previously available health plans. Second, many of the active ingredients contained
only by prescription. Other OTC ingredients previously avail- in OTC medications may worsen existing medical conditions or
able in low doses only are now available in original prescription interact with prescription medications (see Chapter 66, Impor-
strength formulations (eg, ranitidine 150 mg, famotidine 20 mg). tant Drug Interactions & Their Mechanisms). Finally, the misuse
Examples of other prescription medications with the potential for or abuse of OTC products may actually produce significant
future OTC reclassification include oral contraceptives, nicotine medical complications. Phenylpropanolamine, for example, a
replacement therapy (oral inhaler, nasal spray) for smoking cessa- sympathomimetic previously found in many cold, allergy, and
tion, proton-pump inhibitors (pantoprazole) for heartburn, and weight control products, was withdrawn from the US market
second-generation nonsedating antihistamines (desloratadine) for by the FDA based on reports that the drug increased the risk of
relief of allergy and cold symptoms. The prescription-to-OTC hemorrhagic stroke. Dextromethorphan, an antitussive found in
reclassification process is both costly and rigorous, and only select many cough and cold preparations, has been increasingly abused
prescription medications are appropriate candidates for a switch in high doses (eg, >5–10 times the recommended antitussive dose)
(eg, a consumer can self-diagnose and safely treat the condi- by adolescents as a hallucinogen. Although severe complications
tion). For example, the cholesterol-lowering agents lovastatin associated with dextromethorphan as a single agent in overdose
and pravastatin were denied OTC status on the basis that these are uncommon, many dextromethorphan-containing products

TABLE 63–1 Selected agents switched from prescription to over-the-counter status by the US Food and Drug
Administration (2006–2017).

Year Ingredient
Ingredient Indication (Pharmacologic Category) First Switched Single-Ingredient Product Examples
Adapalene Acne (topical retinoid) 2016 Differin Gel
Budesonide Allergic rhinitis (topical glucocorticoid) 2015 Rhinocort Allergy Spray
Cetirizine Hay fever/upper respiratory allergies (antihistamine) 2007 Zyrtec
Esomeprazole Acid reducer (proton-pump inhibitor) 2014 Nexium 24 hour
Fexofenadine Hay fever/upper respiratory allergies (antihistamine) 2011 Allegra 12 hour, Allegra 24 hour
Fluticasone Allergic rhinitis (topical glucocorticoid) 2014 Flonase Allergy Relief, Flonase Sensimist
Allergy-Relief
Ketotifen Itchy eyes (ophthalmic antihistamine) 2006 Alaway, Zaditor
Lansoprazole Acid reducer (proton-pump inhibitor) 2009 Prevacid 24 hour
Levocetirizine Hay fever/upper respiratory allergies (antihistamine) 2017 Xyzal
Levonorgestrel Emergency contraceptive (progestin) 2006 Plan B One-Step
Orlistat Weight loss aid (lipase inhibitor) 2007 Alli
Oxybutynin Overactive bladder (transdermal anticholinergic) 2013 Oxytrol for Women
Polyethylene glycol Constipation (osmotic laxative) 2006 MiraLAX
Triamcinolone Allergic rhinitis (topical glucocorticoid) 2013 Nasacort Allergy 24 hour