Monday, May 17, 2010

Acetaminophen and pseudoephedrine

MEDICATION SAFETY ISSUES
Sound-alike/look-alike issues:
Ornex® may be confused with Orexin®, Orinase®

Duplicate therapy issues: This product contains acetaminophen, which may be a component of other combination products. Do not exceed the maximum recommended daily dose of acetaminophen.

SPECIAL ALERTS
Health Canada: Labeling Changes for OTC Cough and Cold Preparations - December, 2008

Health Canada has issued an advisory to Canadian consumers regarding upcoming labeling changes for the use of over-the-counter (OTC) cough and cold medicines in children. Specific labeling changes as well as other important information may be found at http://www.hc-sc.gc.ca/ahc-asc/media/advisories-avis/_2008/2008_184-eng.php.

Manufacturers Voluntarily Change Pediatric OTC Product Labeling - October 7, 2008

Leading manufacturers of over-the-counter (OTC) pediatric cough and cold products, in consultation with the Food and Drug Administration (FDA), have announced that they are voluntarily transitioning product labeling as it relates to children <4 years of age. The decision to change the labeling followed a meeting on October 2, 2008, conducted by the FDA to gather additional information related to the use of these products in children. The safety of the ingredients in these products was not in question. It was found that dosing errors and accidental ingestions were the leading cause of rare adverse events in children. The new product labeling will state "Do not use in children under four years of age." In addition, products with certain antihistamines will warn parents not to use these products to sedate or make a child sleepy. Labeling of adult products will not change. New product labels will be introduced during the 2008-2009 cough and cold season and some products will have the updated labeling by mid-October. Products with the old labeling will not be removed from the market. Prescription products are not affected.

It is important to note that these medications have not been shown to be unsafe when used correctly. Pharmacists may continue to see health care practitioners recommending these agents for use in pediatric patients, and should help to ensure that they are being used safely and at appropriate dosages. Parents should be advised that OTC cough and cold products are safe and effective when used as directed, but that they should not be used in children <4 years of age unless instructed to do so by their healthcare provider. Counseling tips from the Consumer Healthcare Products Association (CHPA) also include: Always follow dosing instructions exactly and use measuring devices provided with the medicine. Never give 2 medicines at the same time that contain the same active ingredient. Do not give a medicine intended for use in adults to a child.

Additional tips and information related to the labeling changes can be found on the following educational website of the CHPA: http://www.otcsafety.org.

The FDA had previously issued a Public Health Advisory reminding patients and caregivers that OTC cough and cold medications should not be used to treat infants and children <2 years of age. This is in response to the Centers for Disease Control and Prevention (CDC) report which noted that during 2004 and 2005, ~1519 children <2 years of age were seen in emergency departments for adverse effects, including overdose, associated with products containing nasal decongestants (eg, pseudoephedrine), antihistamines (eg, carbinoxamine), and cough suppressants (eg, dextromethorphan). In October of 2007, several manufacturers voluntarily removed these products in order to help reduce dosing errors and overdose in this age group.

For additional information, refer to the following websites:

http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm094913.htm

http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2008/ucm116839.htm

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5601a1.htm, Centers for Disease Control, "Infant Deaths Associated with Cough and Cold Medications - Two States, 2005,"MMWR Morb Mortal Wkly Rep, 2007, 56(01):1-4.

U.S. BRAND NAMES — Ornex® Maximum Strength [OTC]; Ornex® [OTC]

PHARMACOLOGIC CATEGORY
Alpha/Beta Agonist
Analgesic, Miscellaneous

DOSING: ADULTS — Relief of cold, flu or sinusitis symptoms: Oral (Ornex®, Ornex® Maximum Strength): Two caplets every 4-6 hours as needed (maximum: 8 caplets/day)

DOSING: PEDIATRIC
Relief of cold, flu or sinusitis symptoms: Oral:

Children 6-11 years (Ornex®): One caplet every 4-6 hours as needed (maximum: 4 caplets/day)

Children ≥ 12 years: Refer to adult dosing.

DOSING: ELDERLY — Refer to adult dosing.

DOSING: HEPATIC IMPAIRMENT — Use with caution. Limited, low-dose therapy usually well tolerated in hepatic disease/cirrhosis; however, cases of hepatotoxicity at daily acetaminophen dosages <4 g/day have been reported. Avoid chronic use in hepatic impairment.

DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Caplet:
Ornex®: Acetaminophen 325 mg and pseudoephedrine hydrochloride 30 mg
Ornex® Maximum Strength: Acetaminophen 500 mg and pseudoephedrine hydrochloride 30 mg

DOSAGE FORMS: CONCISE
Caplet:
Ornex®: Acetaminophen 325 mg and pseudoephedrine 30 mg
Ornex® Maximum Strength: Acetaminophen 500 mg and pseudoephedrine 30 mg

GENERIC EQUIVALENT AVAILABLE — Yes

USE — Temporary relief of nasal congestion, and minor aches and pains associated with colds, flu, sinusitis, or allergies

ADVERSE REACTIONS SIGNIFICANT — See individual agents.

CONTRAINDICATIONS — MAO inhibitor therapy or within 14 days of therapy; concurrent use with other products containing acetaminophen

WARNINGS / PRECAUTIONS
Disease-related concerns: Ethanol use: Use with caution in patients with alcoholic liver disease; consuming ≥ 3 alcoholic drinks/day may increase the risk of liver damage. Hepatic impairment: Use caution in patients with hepatic impairment; acetaminophen may cause severe hepatic toxicity with acute overdose.

Special populations: Pediatrics: Do not exceed pediatric dosing recommendations. If no recommendations exist on OTC labeling for patient's age, the product should not be administered without the guidance of a physician.

Other warnings/precautions: Dosage limit: Limit acetaminophen dose to <4>7 days or are accompanied by fever that lasts for >3 days, consult a physician. Discontinue and contact healthcare provider if nervousness, dizziness, or sleeplessness occur.

METABOLISM / TRANSPORT EFFECTS — Acetaminophen: Substrate (minor) of CYP1A2, 2A6, 2C9, 2D6, 2E1, 3A4; Inhibits CYP3A4 (weak)

DRUG INTERACTIONS
Antacids: May decrease the excretion of Alpha-/Beta-Agonists. Exceptions: Aluminum Hydroxide. Risk C: Monitor therapy

Anticonvulsants (Hydantoin): May increase the metabolism of Acetaminophen. This may 1) diminish the effect of acetaminophen; and 2) increase the risk of liver damage. Risk C: Monitor therapy

Atomoxetine: May enhance the hypertensive effect of Sympathomimetics. Atomoxetine may enhance the tachycardic effect of Sympathomimetics. Risk C: Monitor therapy

Barbiturates: May increase the metabolism of Acetaminophen. This may 1) diminish the effect of acetaminophen; and 2) increase the risk of liver damage. Risk C: Monitor therapy

Bromocriptine: Alpha-/Beta-Agonists may enhance the adverse/toxic effect of Bromocriptine. Including increased blood pressure, ventricular arrhythmias, and seizure. Risk C: Monitor therapy

Cannabinoids: May enhance the tachycardic effect of Sympathomimetics. Risk C: Monitor therapy

CarBAMazepine: May increase the metabolism of Acetaminophen. This may 1) diminish the effect of acetaminophen; and 2) increase the risk of liver damage. Risk C: Monitor therapy

Carbonic Anhydrase Inhibitors: May decrease the excretion of Alpha-/Beta-Agonists. Exceptions: Brinzolamide; Dorzolamide. Risk C: Monitor therapy

Cholestyramine Resin: May decrease the absorption of Acetaminophen. Effect is minimal if cholestyramine is administered 1 hour after acetaminophen. Risk D: Consider therapy modification

Imatinib: May increase the serum concentration of Acetaminophen. Risk D: Consider therapy modification

Iobenguane I 123: Sympathomimetics may diminish the therapeutic effect of Iobenguane I 123. Risk X: Avoid combination

Isoniazid: May enhance the adverse/toxic effect of Acetaminophen. Risk C: Monitor therapy

MAO Inhibitors: May enhance the hypertensive effect of Alpha-/Beta-Agonists (Indirect-Acting). Risk X: Avoid combination

Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates. Risk C: Monitor therapy

Serotonin/Norepinephrine Reuptake Inhibitors: May enhance the tachycardic effect of Alpha-/Beta-Agonists. Serotonin/Norepinephrine Reuptake Inhibitors may enhance the vasopressor effect of Alpha-/Beta-Agonists. Risk D: Consider therapy modification

Spironolactone: May diminish the vasoconstricting effect of Alpha-/Beta-Agonists. Risk C: Monitor therapy

Sympathomimetics: May enhance the adverse/toxic effect of other Sympathomimetics. Risk C: Monitor therapy

Vitamin K Antagonists (eg, warfarin): Acetaminophen may enhance the anticoagulant effect of Vitamin K Antagonists. Most likely with daily acetaminophen doses >1.3 g for >1 week. Risk C: Monitor therapy

ETHANOL / NUTRITION / HERB INTERACTIONS — Ethanol: Excessive intake of ethanol may increase the risk of acetaminophen-induced hepatotoxicity. Avoid ethanol or limit to <3 drinks/day.

CANADIAN BRAND NAMES — Contac® Cold and Sore Throat, Non Drowsy, Extra Strength; Dristan® N.D.; Dristan® N.D., Extra Strength; Sinutab® Non Drowsy; Sudafed® Head Cold and Sinus Extra Strength; Tylenol® Decongestant; Tylenol® Sinus

INTERNATIONAL BRAND NAMES — Panadol Sinus (AU, HK); Sinumax Ped (ZA); Sinutab (BE)

PHARMACODYNAMICS / KINETICS — See individual agents.

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