|
Therapeutic & Toxic Potential of
Over-the-Counter Agents: Introduction
In the USA,
drugs are divided by law into two classes: those restricted to sale by
prescription only and those for which directions for safe use by the
public can be written. The latter category constitutes the
nonprescription or over-the-counter (OTC) drugs. In 2007, the American
public spent more than $16 billion on over 100,000 OTC products to
medicate themselves for ailments ranging from acne to warts. These
products contain approximately 1000 active ingredients in various forms
and combinations.
It is apparent that many OTC
drugs are no more than "me too" products advertised to the
public in ways that suggest significant differences between them. For
example, there are over 100 different systemic analgesic products, almost
all of which contain aspirin, acetaminophen, nonsteroidal
anti-inflammatory drugs (NSAIDs) such as ibuprofen, or a combination of
these agents as primary ingredients. They are made different from one
another by the addition of questionable ingredients such as caffeine or
antihistamines; by brand names chosen to suggest a specific use or
strength ("women's," "migraine,"
"arthritis," "maximum"); or by special dosage
formulations (enteric-coated tablets, geltabs, liquids, orally
disintegrating strips and tablets, sustained-release products, powders,
seltzers). There is a price attached to all of these features, and in
most cases a less expensive generic product can be equally effective. It
is probably safe to assume that the public is generally overwhelmed and
confused by the wide array of products presented and will probably use
those that are most heavily advertised.
Over the past 35 years, the FDA
has been engaged in a methodical review of OTC ingredients for both
safety and efficacy. There have been two major outcomes of this review:
(1) Ingredients designated as ineffective or unsafe for their claimed
therapeutic use are being eliminated from OTC product formulations (eg,
antimuscarinic agents have been eliminated from OTC sleep aids,
attapulgite and polycarbophil can no longer be marketed as OTC
antidiarrheal products); and (2) agents previously available by
prescription only have been made available for OTC use because they were
judged by the review panel to be generally safe and effective for
consumer use without medical supervision (Table 63–1). Since the
appointment of the Nonprescription Drugs Advisory Committee in 1993, the
rate of switches from prescription to OTC status has accelerated. Indeed,
more than 700 OTC products contain ingredients and dosages that were
available only by prescription less than 30 years ago. Some agents such
as docosanol and the nicotine polacrilex lozenge have bypassed the
prescription route altogether and have been released directly to the OTC
market. Other OTC ingredients previously available in low doses only are
now available in higher-strength or original prescription strength
formulations. Examples of other prescription drugs with the potential for
future OTC reclassification include nicotine replacement therapy (oral
inhaler, nasal spray) for smoking cessation, proton-pump inhibitors
(lansoprazole, pantoprazole) for heartburn, and second-generation
nonsedating antihistamines (desloratadine, fexofenadine, levocetirizine)
for relief of allergy and cold symptoms. The prescription to OTC
reclassification process is very rigorous, and many agents have not been
approved for OTC use. For example, the cholesterol-lowering agents
cholestyramine, lovastatin, and pravastatin were denied OTC status on the
basis that these agents could not be used safely and effectively in an
OTC setting. The advisory committee believed that diagnosis and ongoing
management by a health care professional was necessary for the management
of hyperlipidemia, a chronic, asymptomatic condition with potentially
life-threatening consequences. In a similar recommendation, oral
acyclovir for OTC use in the treatment of recurrent genital herpes was
not approved because of concerns about misdiagnosis and inappropriate use
leading to increased viral resistance.
|
Table 63–1 Selected Agents
Switched from Prescription to OTC Status by the Food and Drug
Administration.
|
|
|
Ingredient
|
Indication
|
Year
Ingredient First Switched
|
Single-Ingredient
Product Examples
|
|
Systemic
agents
|
|
Cetirizine
|
Antihistamine
|
2007
|
Zyrtec
|
|
Cimetidine
|
Acid
reducer (H2 blocker)
|
1995
|
Tagamet HB
|
|
Clemastine
|
Antihistamine
|
1992
|
Tavist
Allergy
|
|
Famotidine
|
Acid
reducer (H2 blocker)
|
1995
|
Pepcid AC
|
|
Ibuprofen
|
Analgesic,
antipyretic (NSAID)
|
1984
|
Advil,
Motrin IB
|
|
Levonorgestrel
|
Emergency
contraceptive
|
2006
|
Plan B
|
|
Loratadine
|
Antihistamine
|
2002
|
Claritin,
Alavert
|
|
Naproxen
sodium
|
Analgesic,
antipyretic (NSAID)
|
1994
|
Aleve
|
|
Nicotine
transdermal system
|
Smoking
cessation
|
1996
|
Nicoderm CQ
|
|
Nicotine
polacrilex gum
|
Smoking
cessation
|
1996
|
Nicorette
|
|
Nizatidine
|
Acid
reducer (H2 blocker)
|
1996
|
Axid AR
|
|
Omeprazole
|
Acid
reducer (proton pump inhibitor)
|
2003
|
Prilosec
OTC
|
|
Orlistat
|
Weight loss
aid
|
2007
|
Alli
|
|
Polyethylene
glycol
|
Laxative
|
2006
|
MiraLax
|
|
Ranitidine
|
Acid
reducer (H2 blocker)
|
1995
|
Zantac 75,
Zantac 150
|
|
Topical agents
|
|
Butenafine
|
Antifungal
(topical)
|
2001
|
Lotrimin
Ultra
|
|
Butoconazole
|
Antifungal
(vaginal)
|
1995
|
Femstat-3
|
|
Clotrimazole
|
Antifungal
(vaginal)
|
1990
|
Gyne-Lotrimin-7,
Gyne-Lotrimin-3
|
|
Cromolyn
|
Nasal
antiallergy
|
1997
|
Nasalcrom
|
|
Ketoconazole
|
Dandruff
shampoo
|
1997
|
Nizoral A-D
|
|
Ketotifen
fumarate
|
Ophthalmic
antihistamine
|
2006
|
Alaway,
Zaditor
|
|
Miconazole
|
Antifungal
(vaginal)
|
1991
|
Monistat-7,
Monistat-3
|
|
Minoxidil
|
Hair growth
stimulant
|
1996
|
Rogaine
Regular and Extra Strength For Men, Rogaine For Women
|
|
Naphazoline/Pheniramine
|
Ophthalmic
decongestant antihistamine
|
1994
|
Naphcon A,
Opcon A, Visine-A
|
|
Permethrin
|
Pediculicide
(head lice)
|
1990
|
Nix
|
|
Terbinafine
|
Antifungal
(topical)
|
1999
|
Lamisil AT
|
|
Tioconazole
|
Antifungal
(vaginal)
|
1997
|
Monistat-1,
Vagistat-1
|
|
|
|
There are three reasons why it
is essential for clinicians to be familiar with the OTC class of products.
First, many OTC medications are effective in treating common ailments,
and it is important to be able to help the patient select a safe,
effective product. Because managed-care practices encourage clinicians to
limit the cost of drugs they prescribe, many will recommend effective OTC
treatments to their patients, since these drugs are rarely paid for by
the insurance plan (Table 63–2). Second, many of the active ingredients
contained in OTC drugs may worsen existing medical conditions or interact
with prescription medications. (See Chapter 66.) Finally, the misuse or
abuse of OTC products may actually produce significant medical
complications. Phenylpropanolamine, for example, a sympathomimetic
previously found in many cold, allergy, and weight control products, was
withdrawn from the United States market by the FDA based on reports that
the drug increased the risk of hemorrhagic stroke. Dextromethorphan, an
antitussive found in many cough and cold preparations, has been
increasingly abused in high doses (eg, > 5–10 times the recommended
antitussive dose) by adolescents as a hallucinogen. Although severe
complications associated with dextromethorphan as a single agent in
overdose are uncommon, many dextromethorphan-containing products are
formulated with other ingredients (acetaminophen, antihistamines, and
sympathomimetics) that can be fatal in overdose. Additionally,
pseudoephedrine, a decongestant contained in numerous OTC cold
preparations, has been used in the illicit manufacture of methamphetamine.
A general awareness of these products and their formulations will enable
clinicians to more fully appreciate the potential for OTC drug-related
problems in their patients.
|
Table 63–2 Ingredients of
Known Efficacy for Selected OTC Classes.
|
|
|
OTC Category
|
Ingredient and Usual Adult
Dosage
|
Product Examples
|
Comments
|
|
Acid
reducers (H2 antagonists)
|
Cimetidine,
200 mg once or twice daily
|
Tagamet HB,
various generic
|
These
products have been approved for the relief of "heartburn, acid
indigestion, and sour stomach." They should not be taken for
longer than 2 weeks and are not recommended for children < 12
years of age.
|
|
Famotidine,
10–20 mg once or twice daily
|
Pepcid AC,
Maximum Strength Pepcid AC, various generic
|
|
Nizatidine,
75 mg once or twice daily
|
Axid AR
|
|
Ranitidine,
75–150 mg once or twice daily
|
Zantac 75,
Zantac 150, various generic
|
|
Acid
reducers (Proton pump inhibitors)
|
Omeprazole
magnesium, 20.6 mg once daily for 14 days
|
Prilosec
OTC, various generic
|
Omeprazole
is the first proton pump inhibitor approved for the treatment of
frequent heartburn in adults (≥ 18 years of age) with symptoms of
heartburn 2 or more days per week. The product should not be taken
for more than 14 days or more often than every 4 months unless
directed by a physician. Omeprazole magnesium 20.6 mg is equivalent
to 20 mg of omeprazole (prescription strength).
|
|
Acne
preparations
|
Benzoyl
peroxide, 5%, 10%
|
Clearasil,
Oxy-10, various generic
|
One of the
most effective acne preparations. Apply sparingly once or twice
daily. Decrease concentration or frequency if excessive skin
irritation occurs.
|
|
Allergy and
"cold" preparations
|
Chlorpheniramine,
4 mg every 4–6 hours; 8–12 mg (extended-release) every 8–12 hours
|
Chlor-Trimeton
Allergy, various generic
|
Antihistamines
alone relieve most symptoms associated with allergic rhinitis or hay
fever. Chlorpheniramine, brompheniramine, and clemastine may cause
less drowsiness than diphenhydramine. Cetirizine and loratadine, both
second-generation antihistamines, are therapeutically comparable to
first-generation agents; these agents have minimal anticholinergic
effects and are therefore associated with a lower incidence of
sedation. Occasionally, symptoms unrelieved by the antihistamine
respond to the addition of a sympathomimetic decongestant. OTC
sale of products containing pseudoephedrine is restricted (see
comments under Decongestants, systemic).
|
|
|
Clemastine,
1.34 mg every 12 hours
|
Tavist
Allergy
|
|
|
Cetirizine,
10 mg every 24 hours
|
Zyrtec,
various generic
|
|
|
Diphenhydramine,
25–50 mg every 4–6 hours
|
Benadryl
Allergy, various generic
|
|
|
Loratadine,
10 mg every 24 hours
|
Alavert,
Claritin, various generic
|
|
|
Brompheniramine
(4 mg) with phenylephrine (10 mg) every 4 hours
|
Dimetapp
Cold & Allergy, various generic
|
|
|
Cetirizine
(10 mg) with pseudoephedrine (120 mg) every 12 hours
|
Zyrtec-D
|
|
|
Chlorpheniramine
(2 mg) with phenylephrine (10 mg) every 4 hours
|
Allerest
PE, Sudafed PE Sinus & Allergy, various generic
|
|
|
Loratadine
(10 mg) with pseudoephedrine (240 mg) every 24 hours
|
Claritin-D
24 Hour
|
|
|
Triprolidine
(2.5 mg) with phenylephrine (10 mg) every 4 hours
|
Actifed
Cold & Allergy, various generic
|
|
Analgesics
and antipyretics
|
Acetaminophen,
325–650 mg every 4–6 hours; 650–1300 mg (extended release) every 8
hours
|
Panadol,
Tylenol, Tylenol 8-Hour, various generic
|
There are
numerous product modifications, including the addition of antacids
and caffeine; enteric-coated tablets and seltzers; long-acting or
extra-strength formulations; and various mixtures of analgesics. None
have any substantial advantage over a single-ingredient product.
Acetaminophen lacks anti-inflammatory activity but is available as a
liquid; this dosage form is used primarily for infants and children
who cannot chew or swallow tablets. Do not exceed a total daily
acetaminophen dose of 4 g (2 g/d in regular alcohol users). Aspirin
should be used cautiously in certain individuals (see text). Use of
OTC products containing aspirin, other salicylates, acetaminophen,
ibuprofen, or naproxen may increase the risk of hepatotoxicity and
gastrointestinal hemorrhage in individuals who consume 3 or more
alcoholic drinks daily. Long-term continuous use of NSAIDs may
increase the risk of heart attack or stroke.
|
|
Aspirin,
325–650 mg every 4–6 hours
|
Bayer
Aspirin, Ecotrin, Bufferin, various generic
|
|
Ibuprofen,
200–400 mg every 4–6 hours (not to exceed 1200 mg daily)
|
Advil,
Motrin IB, various generic
|
|
Naproxen
sodium, 220 mg every 8–12 hours
|
Aleve,
various generic
|
|
Antacids
|
Magnesium
hydroxide and aluminum hydroxide alone or in combination; calcium
carbonate, dosage varies; consult product labeling
|
Alternagel,
Maalox, Milk of Magnesia, Mylanta, Tums, various generic
|
Combinations
of magnesium and aluminum hydroxide are less likely to cause
constipation or diarrhea and offer high neutralizing capacity. Some
preparations include simethicone, an antiflatulent to relieve
symptoms of bloating and pressure.
|
|
Antihelminthics
(pinworm infection)
|
Pyrantel
pamoate, 11 mg/kg (maximum: 1 g)
|
Pin-X,
Reese's Pinworm
|
Treat all
members of the household. Consult physician for children < 2 years
of age or < 25 lb. Undergarments, pajamas, and linens should be
washed daily until the infection is resolved. If symptoms persist
beyond 2 weeks, contact a physician to determine if a repeat dose is
indicated.
|
|
Antidiarrheal
agents
|
Bismuth
subsalicylate, 524 mg every 30–60 minutes as needed up to 8 doses
daily
|
Kaopectate,
Pepto-Bismol, various generics
|
Antidiarrheals
should not be used if diarrhea is accompanied by fever > 101°F or
if blood or mucus is present in stool. Bismuth salts can cause dark
discoloration of the tongue and stools. Salicylates are absorbed and
can cause tinnitus if coadministered with aspirin.
|
|
Loperamide,
4 mg initially, then 2 mg after each loose stool, not to exceed 8 mg
daily
|
Imodium
A-D, various generic
|
Loperamide,
a synthetic opioid, acts on intestinal smooth muscle to decrease
motility allowing for absorption of water and electrolytes. Poorly
penetrates the CNS and has a lower risk of side effects compared with
diphenoxylate or opiates. Not considered a controlled substance.
|
|
Antifungal
topical preparations
|
Butenafine,
1% (cream) apply to affected areas once daily
|
Lotrimin
Ultra
|
Effective
for the treatment of tinea pedis (athlete's foot), tinea cruris (jock
itch), and tinea corporis (ringworm). Clotrimazole and miconazole
also effective against Candida albicans. Clinicians should be
aware that products carrying the same brand name do not necessarily
contain the same active ingredient.
|
|
Clotrimazole,
1% (cream, solution), apply to affected areas twice daily (morning
and evening)
|
Lotrimin AF
cream, various generic
|
|
Miconazole,
2% (cream, powder, solution), apply to affected areas twice daily
(morning and night)
|
Cruex,
Desenex, Lotrimin AF (powder, spray), Zeasorb-AF
|
|
Terbinafine,
1% (cream, solution, spray), apply to affected areas once daily
(ringworm) or twice daily (athlete's foot/jock itch)
|
Lamisil AT
|
|
Tolnaftate,
1% (cream, powder, spray, solution), apply to affected areas twice
daily (morning and night)
|
Tinactin,
Ting cream, various generic
|
|
Undecylenic
acid, 12–25% (powder, solution) apply to affected areas twice daily
|
Blis-To-Sol,
Elon Dual Defense Anti-Fungal
|
|
Antifungal
vaginal preparations
|
Butoconazole,
2% cream, one applicatorful intravaginally at bedtime for 3
consecutive days
|
Femstat-3
|
Topical
vaginal antifungals should only be used for treatment of recurrent
vulvovaginal candidiasis in otherwise healthy, nonpregnant women
previously diagnosed by a clinician.
|
|
Clotrimazole
(1%, 2% vaginal cream, 100 mg, 200 mg tablet); see comments for
dosage
|
Gyne-Lotrimin-7,
Gyne-Lotrimin-3, various generic
|
Insert one
applicatorful (1%) or one tablet (100 mg) intravaginally at bedtime
for 7 consecutive days. Alternatively: Insert one applicatorful (2%)
or one tablet (200 mg), intravaginally at bedtime for 3 consecutive
days.
|
|
Miconazole
(2%, 4% vaginal cream; 100 mg, 200 mg vaginal suppositories); see
comments for dosage
|
Monistat-7,
Monistat-3, Vagistat-3, various generic
|
Insert one
applicatorful intravaginally at bedtime for 7 consecutive days (2%)
or 3 consecutive days (4%). Alternatively: Insert one suppository
intravaginally at bedtime for 7 consecutive days (100 mg) or 3
consecutive days (200 mg).
|
|
Tioconazole,
6.5% vaginal ointment, one applicatorful intravaginally at bedtime
(single dose)
|
Monistat-1,
Vagistat-1, various generic
|
|
|
Anti-inflammatory
topical preparations
|
Hydrocortisone,
0.5% (cream, ointment, lotion), 1% (cream, ointment, lotion, spray)
|
Cortaid,
Cortizone-10, Preparation H, various generic
|
Used to
temporarily relieve itching and inflammation associated with minor
rashes due to contact or allergic dermatitides, insect bites, and
hemorrhoids. Apply sparingly to affected areas two to four times
daily.
|
|
Antiseborrheal
agents
|
Coal tar,
0.5-5% shampoo, dosage varies; consult product labeling
|
Denorex
Therapeutic, Ionil T Plus, Pentrax 5%, various generic
|
Tar
derivatives inhibit epidermal proliferation and may possess
antipruritic and antimicrobial activity.
|
|
Ketoconazole,
1% shampoo, apply every 3–4 days
|
Nizoral A-D
|
Synthetic
azole antifungal agent with activity versus Pityrosporum ovale,
a fungus that may cause seborrhea and dandruff. Massage over entire
scalp for 3 minutes. Rinse thoroughly and repeat application.
|
|
Pyrithione
zinc, 1–2% shampoo, apply once or twice weekly
|
Denorex
Daily, Head & Shoulders, Sebulon, various generic
|
Both
selenium sulfide and zinc pyrithione are cytostatic agents that
decrease epidermal turnover rates. Massage into wet scalp for 2–3 minutes.
Rinse thoroughly and repeat application. Selenium sulfide can be
irritating to the eyes and skin.
|
|
Selenium
sulfide, 1% shampoo, apply once or twice weekly
|
Head &
Shoulders Intensive Treatment, Selsun Blue, various generic
|
|
Antitussives
|
Codeine,
10–20 mg every 4–6 hours, not to exceed 120 mg in 24 hours (with
guaifenesin)
|
Guiatuss
AC, Mytussin AC, various generic
|
Acts
centrally to increase the cough threshold. In doses required for
cough suppression, the addiction liability associated with codeine is
low. Many codeine-containing antitussive combinations are schedule V
narcotics, and OTC sale is restricted in some states.
|
|
Dextromethorphan,
10–20 mg every 4 hours or 30 mg every 6–8 hours; 60 mg
(extended-release suspension) every 12 hours
|
Delsym
12-Hour Cough, Hold DM, Vicks 44 Dry Cough, various generic
|
Dextromethorphan
is a nonopioid congener of levorphanol without analgesic or addictive
properties. Often is used with antihistamines, decongestants, and
expectorants in combination products. In high dosages (> 2 mg/kg)
dextromethorphan can induce phencyclidine-like hallucinogenic
effects.
|
|
Decongestants,
topical
|
Oxymetazoline,
0.05% nasal solution, 2–3 sprays per nostril twice daily
|
Afrin,
Neo-Synephrine 12 Hour, Sudafed OM, Vicks Sinex, various generic
|
Topical
sympathomimetics are effective for the temporary acute management of
rhinorrhea associated with common colds and allergies. Long-acting
agents (oxymetazoline and xylometazoline) are generally preferred,
although phenylephrine is equally effective. Topical decongestants
should not be used for longer than 3 days to prevent rebound nasal
congestion.
|
|
Phenylephrine
(0.25%, 0.5%, 1%), nasal solution, 2–3 sprays/drops per nostril no
more often than every 4 hours
|
Neo-Synephrine,
various generic
|
|
Xylometazoline
(0.05%, 0.1%), nasal solution, 2–3 drops or 1–3 sprays per nostril
every 8–10 hours
|
Otrivin
|
|
Decongestants,
systemic
|
Phenylephrine,
10 mg every 4 hours
|
Sudafed PE,
various generic combination products
|
Oral
decongestants have a prolonged duration of action but may cause more
systemic effects, including nervousness, excitability, restlessness,
and insomnia. Also available in antihistamine, antitussive,
expectorant, and analgesic combination products. Federal regulations
established to discourage the illicit manufacture of methamphetamine
specify that all drug products containing pseudoephedrine must be
stored in locked cabinets or behind the pharmacy counter and can only
be sold in limited quantities to consumers after they provide photo
identification and sign a logbook.
|
|
Pseudoephedrine,
60 mg every 4–6 hours or 120 mg (extended release) every 12 hours, or
240 mg (extended release) every 24 hours
|
Sudafed,
various generic
|
|
Emergency
contraceptive
|
Levonorgestrel,
0.75 mg tablet taken as soon as possible but no later than 72 hours
after unprotected intercourse; repeat dosage 12 hours later
|
Plan B
|
Levonorgestrel
prevents ovulation and may inhibit fertilization or implantation.
Reduces the chance of pregnancy by up to 89% when taken as directed
within 72 hours after unprotected intercourse. Plan B is available
behind the counter at pharmacies and sold under the supervision of a
licensed pharmacist. A prescription is needed for women ≤ 17 years of
age.
|
|
Expectorants
|
Guaifenesin,
100–400 mg every 4 hours; 600–1200 mg (extended release) every 12
hours
|
Glytuss,
Robitussin, various generic
|
The only
OTC expectorant recognized as safe and effective by the FDA. Often
used with antihistamines, decongestants, and antitussives in
combination products.
|
|
Hair growth
stimulants
|
Minoxidil,
2%, 5% solution, apply 1 mL to affected areas of scalp twice daily.
|
Rogaine for
Men, Rogaine for Women, Rogaine Extra Strength for Men
|
Minoxidil
appears to directly stimulate hair follicles resulting in increased
hair thickness and reduced hair loss. Treatment for 4 months or
longer may be necessary to achieve visible results. If new hair
growth is observed, continued treatment is necessary as hair density
returns to pretreatment levels within months following drug
discontinuation.
|
|
Laxatives
|
Bulk
formers: Polycarbophil, psyllium, and methylcellulose preparations.
Dosage varies; consult product labeling
|
Citrucel,
Fibercon, Konsyl, Metamucil, Perdiem, various generic
|
The safest
laxatives for chronic use include the bulk formers and stool
softeners. Saline laxatives and stimulants may be used acutely but
not chronically (see text). Bulk formers hold water and expand in
stool, promoting peristalsis.
|
|
Hyperosmotics:
Glycerin, 2–3 g suppository per rectum daily. Polyethylene glycol
3350 (powder), 17 g dissolved in 4–8 oz of beverage daily
|
Fleet
Glycerin Suppository, various generic; MiraLax
|
Glycerin
induces a local irritant effect in combination with an osmotic
effect. Polyethylene glycol formulations are large, poorly absorbed
molecules that induce an osmotic effect causing distention and
catharsis.
|
|
Stool
softeners: Docusate sodium, 50–500 mg daily. Docusate calcium, 240 mg
daily
|
Colace,
Kaopectate Stool Softener, various generic
|
Softens
fecal material via detergent action that allows water to penetrate
stool.
|
|
Stimulant
laxatives: Bisacodyl, 5–15 mg daily. Senna, dosage varies, consult
product labeling
|
Correctol,
Dulcolax, Ex-Lax, Senokot, various generic
|
Stimulant
laxative actions include direct irritation of intestinal mucosa or
stimulation of the myenteric plexus, resulting in peristalsis. These agents
may also cause alteration of fluid and electrolyte absorption,
resulting in luminal fluid accumulation and bowel evacuation.
|
|
Pediculicides
(head lice)
|
Permethrin
1%
|
Nix
|
Instructions
for use vary; consult product labeling. Avoid contact with eyes. Comb
out nits. Linens, pajamas, combs, and brushes should be washed daily
until the infestation is eliminated. For pyrethrin products, retreat
in 7–10 days to kill any newly hatched nits. Permethrin products have
residual effects for up to 10 days; therefore, reapplication is not
required unless live nits are visible 7 days or more after the
initial treatment.
|
|
Pyrethrins
(0.3%) combined with piperonyl butoxide (3–4%)
|
A-200, RID
|
|
Sleep aids
|
Diphenhydramine,
25–50 mg at bedtime
|
Nytol,
Simply Sleep, Sominex, various generic
|
Diphenhydramine
and doxylamine are antihistamines with well-documented CNS depressant
effects. Because insomnia may be indicative of a serious underlying
condition requiring medical attention, patients should consult a
physician if insomnia persists continuously for longer than 2 weeks.
|
|
Doxylamine,
25 mg 30 minutes before bedtime
|
Unisom,
various generic
|
|
Smoking
cessation aids
|
Nicotine
polacrilex gum; dosage varies; consult product labeling
|
Nicorette,
various generic
|
Nicotine
replacement products in combination with behavioral support
approximately double long-term cessation rates compared with placebo.
Review directions for use carefully, since product strengths vary and
self-titration and tapering may be necessary.
|
|
Nicotine
polacrilex lozenge, dosage varies; consult product labeling
|
Commit,
various generic
|
|
Nicotine
(transdermal system), dosage varies; consult product labeling
|
Nicoderm
CQ, various generic
|
|
Weight loss
aids
|
Orlistat,
60 mg with each meal containing fat (not to exceed 180 mg/d)
|
Alli
|
Approved
for weight loss in overweight adults ≥ 18 years of age when used in
combination with a reduced-calorie, low-fat diet and exercise
program. Orlistat is a nonsystemically absorbed inhibitor of
gastrointestinal lipase that blocks the absorption of dietary fat.
OTC formulation is a half-strength version of the prescription
product (Xenical).
|
|
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Table 63–2 lists examples of OTC
products that may be used effectively to treat common medical problems.
The selection of one ingredient over another may be important in patients
with certain medical conditions or in patients taking other medications.
These are discussed in detail in other chapters. The recommendations
listed in Table 63–2 are based on the efficacy of the ingredients and on
the principles set forth in the following paragraphs.
1.
Select
the product that is simplest in formulation with regard to ingredients
and dosage form. In general, single-ingredient products are preferred.
Although some combination products contain effective doses of all
ingredients, others contain therapeutic doses of some ingredients and
subtherapeutic doses of others. Furthermore, there may be differing
durations of action among the ingredients, and there is always a
possibility that the clinician or patient is unaware of the presence of
certain active ingredients in the product. Acetaminophen, for example, is
in many cough and cold preparations; a patient unaware of this may take
separate doses of analgesic in addition to that contained in the cold
preparation, potentially leading to hepatotoxicity.
2.
Select
a product that contains a therapeutically effective dose.
3.
Carefully
read the product labeling to determine which ingredients are appropriate
based on the patient's symptoms and underlying health conditions and
whatever is known about the medications the patient is already taking.
4.
Recommend
a generic product if one is available.
5.
Be
wary of "gimmicks" or advertising claims of specific
superiority over similar products.
6.
For
children, the dose, dosage form, and palatability of the product are
prime considerations.
Certain ingredients in OTC
products should be avoided or used with caution in selected patients
because they may exacerbate existing medical problems or interact with
other medications the patient is taking. Many of the more potent OTC
ingredients are hidden in products where their presence would not
ordinarily be expected (Table 63–3). Although OTC medications have
standardized label formatting and content requirements that specify the
indications for use, dosage, warnings, and active and inactive
ingredients contained in the product, many consumers do not carefully
read or comprehend this information. Lack of awareness of the ingredients
in OTC products and the belief by many physicians that OTC products are
ineffective and harmless may cause diagnostic confusion and perhaps
interfere with therapy. For example, innumerable OTC products, including
analgesics and allergy, cough, and cold preparations, contain
sympathomimetics. These agents should be avoided or used cautiously by type
1 diabetics and patients with hypertension, angina, or hyperthyroidism.
Aspirin should not be used in children and adolescents for viral
infections (with or without fever) because of an increased risk of Reye's
syndrome. Aspirin and other NSAIDs should be avoided by individuals with
active peptic ulcer disease, certain platelet disorders, and patients
taking oral anticoagulants. Cimetidine, an H2-receptor
antagonist, is a well-known inhibitor of hepatic drug metabolism and can
increase the blood levels and toxicity of drugs such as phenytoin,
theophylline, and warfarin.
|
Table 63–3 Hidden Ingredients
in OTC Products.
|
|
|
Hidden Drug
or Drug Class
|
OTC Class
Containing Drug
|
Product
Examples
|
|
Alcohol
(percent ethanol)
|
Cough
syrups, cold preparations
|
Theraflu
Nighttime (10%); Vicks NyQuil Cold & Flu Liquid (10%); Vicks
NyQuil Cough (10%)
|
|
Mouthwashes
|
Listerine
(27%); Scope (15%); Cepacol (14%)
|
|
Antihistamines
|
Analgesics
|
Advil PM;
Alka-Seltzer PM; Excedrin PM; Bayer PM; Extra Strength Doan's PM;
Goody's PM Pain Relief Powder; Tylenol PM
|
|
Menstrual
products
|
Midol
Menstrual Complete; Pamprin Multi-Symptom
|
|
Sleep aids
|
Nytol;
Simply Sleep; Sominex; Unisom
|
|
Aspirin and
other salicylates
|
Antidiarrheals
|
Pepto-Bismol
(bismuth subsalicylate); Kaopectate (bismuth subsalicylate)
|
|
Cold/allergy
preparations
|
Alka-Seltzer
Plus Flu
|
|
Caffeine
(mg/tablets or as stated)
|
Analgesics
|
Alka-Seltzer
Wake-Up Call (65); Anacin (32); Anacin Advanced Headache Formula
(65); Arthritis Strength BC (38/pre-measured packet); BC Powder
(33/pre-measured packet); Excedrin Extra Strength (65); Excedrin
Migraine (65); Excedrin Tension Headache (65) Goody's Extra Strength
Headache Powder (33/pre-measured packet); Goody's Cool Orange
(65/pre-measured packet)
|
|
Menstrual
products
|
Midol
Menstrual Complete (60); Pamprin Max (65)
|
|
Stimulants
|
NoDoz
(200); Vivarin (200)
|
|
Local
anesthetics (usually benzocaine)
|
Antitussives/Lozenges
|
Cepacol
Instant Relief Sore Throat Lozenges; Chloraseptic Sore Throat;
Sucrets; Sucrets Complete
|
|
Dermatologic
preparations
|
Americaine;
Bactine; Dermoplast; Lanacane; Solarcaine
|
|
Hemorrhoidal
products
|
Americaine
Ointment; Nupercainal; Tronolane; Tucks Ointment
|
|
Toothache,
cold sore, and teething products
|
Anbesol;
Kank-A; Orajel; Zilactin-B
|
|
Sodium
(mg/tablet or as stated)
|
Analgesics
|
Alka-Seltzer
Original Effervescent Tablet (568); Alka-Seltzer Extra Strength Effervescent
Tablet (588); Bromo-Seltzer Granules (959/pre-measured packet)
|
|
Antacids
|
Alka-Seltzer
Original Effervescent Tablet (568); Alka-Seltzer Extra Strength
Effervescent Tablet (588); Alka-Seltzer Gold (309); Alka-Seltzer
Heartburn Relief (575); Brioschi (500/6 g dose); Bromo-Seltzer
Granules (959/pre-measured packet); Citrocarbonate Effervescent
Granules (701/tsp)
|
|
|
Cold/cough
preparations
|
Alka-Seltzer
Plus Formulations: Cold (503); Day Cold (416); Cold & Cough
(416); Flu (387); Mucous & Congestion (296); Night Cold (477).
|
|
|
Laxatives
|
Fleets
Enema (4,439 mg, of which 275–400 mg/enema is absorbed)
|
|
Sympathomimetics
|
Analgesics
|
Excedrin
Sinus Headache; Sine-Off; Sinutab; Tylenol Congestion & Pain;
Tylenol Sinus Severe Congestion
|
|
Asthma
products
|
Bronkaid
Dual Action; Primatene Mist; Primatene Tablets
|
|
Cold/cough/allergy
preparations
|
Actifed
Cold & Allergy; Advil Cold & Sinus; Alka-Seltzer Plus (many);
Comtrex Severe Cold & Sinus; Congestac; Contac Day & Night
Cold & Flu; Dimetapp Cold & Chest Congestion; Dristan Cold;
PediaCare (many); Motrin Cold & Sinus; Ornex; Robitussin Cough,
Cold & Flu; Robitussin Cough & Cold CF; Sudafed PE Cold &
Cough; TheraFlu Warming Relief Multisymptom Cold; Triaminic (many);
Tylenol Cold Multisymptom; Tylenol Cold Severe Congestion; Tylenol
Allergy Multisymptom; Vicks 44 Congestion; Vicks DayQuil
|
|
Hemorrhoidal
products
|
Hemorid;
Preparation H (cream, ointment, suppository)
|
|
|
|
Overuse or misuse of OTC
products may induce significant medical problems. A prime example is
rebound congestion from the regular use of decongestant nasal sprays for
more than 3 days. The improper and long-term use of some antacids (eg,
aluminum hydroxide) may cause constipation and even impaction in elderly
people, as well as hypophosphatemia. Laxative abuse can result in
abdominal cramping and fluid and electrolyte disturbances. Insomnia,
nervousness, and restlessness can result from the use of sympathomimetics
or caffeine hidden in many OTC products (Table 63–3). The long-term use
of some analgesics containing large amounts of caffeine may produce
rebound headaches, and long-term use of analgesics has been associated
with interstitial nephritis. OTC products containing aspirin, other
salicylates, acetaminophen, ibuprofen, or naproxen may increase the risk
of hepatotoxicity and gastrointestinal hemorrhage in individuals who
consume three or more alcoholic drinks daily. Recent evidence suggests
the long-term use of NSAIDs may increase the risk of heart attack or
stroke. Furthermore, acute ingestion of large amounts of acetaminophen by
adults or children can cause serious, and often fatal, hepatotoxicity.
Antihistamines may cause sedation or drowsiness, especially when taken
concurrently with sedative-hypnotics, tranquilizers, alcohol, or other
central nervous system depressants. Antihistamines and other substances
contained in OTC topical and vaginal products may induce allergic
reactions.
Finally, use of OTC cough and
cold preparations in the pediatric population has been under scrutiny by
the FDA based on a lack of efficacy data in children less than 12 years
of age and reports of serious toxicity in children. In October 2007, many
pharmaceutical manufacturers recalled OTC cough and cold preparations
marketed for children less than 2 years of age. In 2008, the FDA issued
an advisory alert recommending that OTC cough and cold agents not be used
in infants and children less than 2 years of age due to the potential for
serious and possibly life-threatening adverse events. More recently, in
October 2008, leading pharmaceutical manufacturers voluntarily modified
product labels on OTC cough and cold preparations to state, "do not
use" in children under 4 years of age. Further safety reviews by the
FDA regarding the use of these agents in children between the ages of 2
and 11 are ongoing.
There are three major drug
information sources for OTC products. Handbook of Nonprescription
Drugs is the most comprehensive resource for OTC medications; it
evaluates ingredients contained in major OTC drug classes and lists the
ingredients included in many OTC products. Nonprescription Drug
Therapy is an online reference that is updated monthly; it provides
detailed OTC product information and patient counseling instructions. Physicians'
Desk Reference for Nonprescription Drugs, Dietary Supplements and Herbs,
a compendium of manufacturers' information regarding OTC products, is
published annually but is somewhat incomplete with regard to the number
of products included. Any health care provider who seeks more specific
information regarding OTC products may find useful the references listed
below.
|