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Drug

CPM-Phenyleph-Acetaminophen

Drug Interactions

See also Warning section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug are: ketoconazole, levoketoconazole.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or other antihistamines (such as cetirizine, diphenhydramine).

The ingredients in this product are available in many prescription and nonprescription products. Check the labels on all your medicines (such as pain/fever drugs, diet aids, or cough-and-cold/allergy products) because they may contain the same or similar ingredients. Using these drugs along with this product could increase side effects (such as fast heartbeat, increased blood pressure, or drowsiness). Ask your pharmacist about using those products safely.

Do not use with any other antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray) because increased side effects may occur.

This medication may interfere with certain lab tests (such as urine drug screening tests, urine 5-HIAA, allergy skin test), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

  • Negative Interactions

    3

    • Acetaminophen

      N-Acetyl Cysteine

      Potential Negative Interaction

      Hospitals use oral and intravenous NAC to treat liver damage induced by acetaminophen overdose poisoning. NAC is often administered intravenously by emergency room doctors. Oral NAC appears to be effective for acetaminophen toxicity.

      An uncontrolled trial compared intravenous NAC with oral NAC in children with acetaminophen poisoning and found that both methods were equally effective in reversing acetaminophen-induced liver toxicity. However, acetaminophen toxicity is a potential medical emergency, and should only be managed by qualified healthcare professionals.

      N-Acetyl Cysteine
      Acetaminophen
      ×
      1. Vale JA, Proudfoot AT. Paracetamol (acetaminophen) poisoning. Lancet 1995;346:547-52.
      2. Perry HE, Shannon MW. J Pediatr 1998;132:149-52.

    • Acetaminophen

      Cruciferous Vegetables

      Reduces Effectiveness

      Food, especially foods high in pectin (including jellies), carbohydrates, and many types of cruciferous vegetables (broccoli, Brussels sprouts, cabbage, and others) can interfere with acetaminophen absorption. It is unclear how much effect this interaction has on acetaminophen activity.

      Cruciferous Vegetables
      Acetaminophen
      ×
      1. Holt GA. Food & Drug Interactions. Chicago: Precept Press, 1998, 2.

    • Acetaminophen

      Hibiscus

      Reduces Effectiveness

      One small study found that hibiscus could decrease levels of acetaminophen if the drug was taken after the tea was consumed though it was not entirely clear if the decreases were clinically significant.

      Hibiscus
      Acetaminophen
      ×
      1. Kolawole JA, Maduenyi A. Effect of zobo drink (Hibiscus sabdariffa water extract) on the pharmacokinetics of acetaminophen in human volunteers. Eur J Drug Metab Pharmacokinet 2004;29:25-9.

  • Supportive Interactions

    1

    • Acetaminophen

      Milk Thistle

      Reduce Side Effects

      Silymarin is a collection of complex flavonoids found in milk thistle (Silybum marianum) that has been shown to elevate liver glutathione levels in rats. Acetaminophen can cause liver damage, which is believed to involve glutathione depletion. In one study involving rats, silymarin protected against acetaminophen-induced glutathione depletion. While studies to confirm this action in humans have not been conducted, some doctors recommend silymarin supplementation with 200 mg milk thistle extract, containing 70–80% silymarin, three times per day for people taking acetaminophen in large amounts for more than one year and/or with other risk factors for liver problems.

      Milk Thistle
      Acetaminophen
      ×
      1. Valenzuela A, Aspillaga M, Vial S, Guerra R. Selectivity of silymarin on the increase of the glutathione content in different tissues of the rat. Planta Med 1989;55:420-2.
      2. Threlkeld DS, ed. Central Nervous System Drugs, Acetaminophen. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Mar 1997, 247-f.
      3. Campos R, Garrido A, Guerra R, Valenzuela A. Silybin dihemisuccinate protects against glutathione depletion and lipid peroxidation induced by acetaminophen on rat liver. Planta Med 1989;55:417-9.

  • Explanation Required

    2

    • Acetaminophen

      Schisandra

      Needs Explanation

      Gomisin A is a constituent found in the Chinese herb schisandra (Schisandra chinensis). In a study of rats given liver-damaging amounts of acetaminophen, gomisin A appeared to protect against some liver damage but did not prevent glutathione depletion (unlike milk thistle, as reported above). Studies have not yet confirmed this action in humans.

      Schisandra
      Acetaminophen
      ×
      1. Yamada S, Murawaki Y, Kawasaki H. Preventive effect of gomisin A, a lignan component of schizandra fruits, on acetaminophen-induced hepatotoxicity in rats. Biochem Pharmacol 1993;46:1081-5.

    • Acetaminophen

      Vitamin C

      Needs Explanation

      Taking 3 grams vitamin C with acetaminophen has been shown to prolong the amount of time acetaminophen stays in the body. This theoretically might allow people to use less acetaminophen, thereby reducing the risk of side effects. Consult with a doctor about this potential before reducing the amount of acetaminophen. However, increasing the time acetaminophen is in the body might also theoretically increase its toxicity. Consult with a doctor before taking vitamin C along with acetaminophen.

      Vitamin C
      Acetaminophen
      ×
      1. Houston JB, Levy G. Drug biotransformation interactions in man. VI: Acetaminophen and ascorbic acid. J Pharm Sci 1976;65:1218-21.
      2. FDA Information on Acetaminophen, Jan 13, 2011. http://www.fda.gov/Drugs/DrugSafety/InformationbyDrugClass/ucm165107.htm

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Drug information is selected from data included with permission and copyrighted by First DataBank, Inc. This is a summary and does not contain all possible information about this product. For complete information about this product or your specific health needs, ask your healthcare professional. Always seek the advice of your healthcare professional if you have any questions about this product or your medical condition. This information is not intended as individual medical advice and does not substitute for the knowledge and judgment of your healthcare professional. This information does not contain any assurances that this product is safe, effective or appropriate for you.

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