Page 1136 - Basic _ Clinical Pharmacology ( PDFDrive )

1122 SECTION X Special Topics

are formulated with other ingredients (acetaminophen, antihis- of methamphetamine. A general awareness of these products and
tamines, and sympathomimetics) that can be fatal in overdose. their formulations will enable clinicians to more fully appreci-
Loperamide is sometimes used in large doses to create an opioid- ate the potential for OTC medication-related problems in their
like high or to self-treat opioid withdrawal symptoms. In large patients.
doses, loperamide may cross the blood-brain barrier and cause Table 63–2 lists examples of OTC products that may be used
altered mental status and respiratory depression; additionally, lop- effectively to treat common medical problems. The selection
eramide may induce ventricular arrhythmias in supratherapeutic of one ingredient over another may be important in patients
doses. Pseudoephedrine, a decongestant contained in numerous with certain medical conditions or in patients taking other
OTC cold preparations, has been used in the illicit manufacture medications. These are discussed in detail in other chapters.

TABLE 63–2 Ingredients of known efficacy for selected over-the-counter (OTC) classes.

Generic Name
OTC Category (Brand Example) Labeled Use Warnings Considerations
Acid reducers Cimetidine Relief and Avoid use: in children <12 years • To prevent symptoms, take 30–60 minutes
(H 2 antagonists) (Tagamet HB) prevention of of age; if patient has trouble or before consuming food or beverages that
heartburn asso- pain swallowing food, vomiting cause heartburn.
Famotidine ciated with acid with blood, or bloody or black
(Pepcid AC) indigestion. stools; with other acid reducers; • Cimetidine may increase the serum
concentrations of theophylline, warfarin,
Ranitidine if symptoms include heartburn and phenytoin.
(Zantac 75, with lightheadedness, sweating,
Zantac 150) dizziness, or chest pain; for
treatment durations >14 days.
Adverse effects include: nausea,
agitation, headache, dizziness,
agitation, and gynecomastia
(cimetidine; rare).
Acid reducers Esomeprazole Treatment of Avoid use: in children <18 years • Not intended for immediate relief (products
(proton-pump (Nexium 24 hour) frequent heart- of age; if patient has trouble or take 1–4 days for full effect).
inhibitors [PPI]) burn (occurs pain swallowing food, vomiting • Take with water before eating in the
Lansoprazole 2 or more days with blood, or bloody or black
(Prevacid 24 hour) a week). stools; if symptoms include morning.
Omeprazole (Pri- heartburn with lightheaded- • Patients may repeat a 2-week course of
therapy every 4 months.
losec OTC) ness, sweating, dizziness,
or chest pain; for treatment • PPI therapy can increase risk of Clostridium
durations >14 days. difficile-associated diarrhea and risk of
fracture.
Adverse effects include: head-
ache, abdominal pain, nausea, • Esomeprazole, lansoprazole, and
diarrhea, and flatulence. omeprazole may interact with warfarin,
clopidogrel, cilostazol, antifungal
medications, diazepam, digoxin, tacrolimus,
and HIV antiretrovirals.
Allergy Chlorpheniramine Temporary relief Avoid use: in children <2 years • Diphenhydramine is the most sedating
preparations (Chlor-Trimeton) of the following of age; in combination with antihistamine.
symptoms due other sedatives and alcohol
Clemastine (Tavist to hay fever or as sedative effects may be • Consult product labeling before use in
Allergy) upper respiratory potentiated. Use caution when children ages 2–11 years.
Cetirizine (Zyrtec) allergies: driving or operating machinery. • First-generation antihistamines (chlorpheni-
ramine, clemastine, diphenhydramine) may
sneezing, runny
Diphenhydramine nose, itchy, Adverse effects include: drowsi- cause excitability in children.
(Benadryl Allergy) watery eyes, ness, dizziness, fatigue, nausea, • Second-generation antihistamines
itching of nose and urinary retention. (cetirizine, fexofenadine, levocetirizine,
Fexofenadine (Allegra or throat. loratadine) have minimal anticholinergic
12 hour, Allegra Antihistamines are contained effects and are associated with lower
24 hour) in many OTC preparations in
combination with analgesics, chances of sedation.
Levocetirizine (Xyzal) decongestants, and expectorants.
See the warnings section for
Loratadine (Alavert, each formulation.
Claritin)
(continued)