Health Encyclopedia > Medications

diphenhydramine and magnesium salicylate

Pronunciation: DYE fen HYE dra meen and mag NEE ze um sa LIS a late

Brand: Doans PM

What is the most important information I should know about diphenhydramine and magnesium salicylate?

Multum nochild

This medication should not be given to a child or teenager who has a fever, especially if the child also has flu symptoms or chicken pox. Magnesium salicylate can cause a serious and sometimes fatal condition called Reye's syndrome in children.

Multum donot

You should not use this medication if you are allergic to diphenhydramine or magnesium salicylate.

Before taking this medication, tell your doctor if you have a breathing disorder, heart disease, high blood pressure, kidney or liver disease, diabetes, a thyroid disorder, glaucoma, stomach ulcer, hemophilia or other bleeding disorder, anemia, gout, enlarged prostate, urination problems, nasal polyps, or an allergy to an NSAID (non-steroidal anti-inflammatory drug) such as Advil, Motrin, Aleve, Indocin, Relafen, Feldene, and others.

Multum noalcohol

Drinking alcohol may increase your risk of stomach bleeding while taking magnesium salicylate.

Multum dizzy

This medication can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Multum donot

Do not use an over-the-counter cough, cold, allergy, or sleep medication without first asking your doctor or pharmacist. Read the label of any other medicine you are using to see if it contains diphenhydramine or another antihistamine.

Multum donot

There are many other medicines that can interact with diphenhydramine and magnesium salicylate. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you.

What is diphenhydramine and magnesium salicylate?

Diphenhydramine is an antihistamine that reduces the natural chemical histamine in the body. It is often used as a sleep aid due to its common side effect of drowsiness.

Magnesium salicylate is in a class of drugs called salicylates (sa-LIS-il-ates). It works by reducing substances in the body that cause pain and inflammation.

The combination of diphenhydramine and magnesium salicylate is used to treat back pain that keeps you awake during your normal sleeping hours.

Diphenhydramine and magnesium salicylate may also be used for other purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking diphenhydramine and magnesium salicylate?

Multum donot

You should not use this medication if you are allergic to diphenhydramine or magnesium salicylate.

Before taking this medication, tell your doctor if you are allergic to any drugs, or if you have:

  • asthma, emphysema, or chronic bronchitis;
  • heart disease or high blood pressure;
  • kidney or liver disease;
  • diabetes;
  • a thyroid disorder;
  • glaucoma;
  • stomach ulcer or GERD (gastroesophageal reflux disease);
  • a bleeding disorder such as hemophilia;
  • anemia (lack of red blood cells);
  • gout;
  • an enlarged prostate or problems with urination;
  • nasal polyps caused by asthma or aspirin allergy; or
  • an allergy to an NSAID (non-steroidal anti-inflammatory drug) such as Advil, Motrin, Aleve, Orudis, Indocin, Lodine, Voltaren, Toradol, Mobic, Relafen, Feldene, and others.

If you have any of these conditions, you may need a dose adjustment or special tests to safely take this medication.

Multum nopreg

This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Multum nobrfeed

This medication may pass into breast milk and could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Older adults may be more likely to have side effects from this medication.

Multum nochild

This medication should not be given to a child or teenager who has a fever, especially if the child also has flu symptoms or chicken pox. Magnesium salicylate can cause a serious and sometimes fatal condition called Reye's syndrome in children.

How should I take diphenhydramine and magnesium salicylate?

Use this medication exactly as directed on the label, or as it has been prescribed by your doctor. Do not use the medication in larger amounts, or use it for longer than recommended.

Multum water

Take diphenhydramine and magnesium salicylate 15 to 30 minutes before bedtime with a full glass of water. Avoid lying down for at least 15 minutes after taking the medicine.

You may take the medicine with food or milk if it upsets your stomach.

Multum emt

Talk with your doctor if your symptoms do not improve after 10 days of using this product, or 3 days if you also have a fever.

Diphenhydramine and magnesium salicylate can cause you to have unusual results with certain medical tests. Tell any doctor who treats you that you are taking diphenhydramine and magnesium salicylate.

Multum emt

If you need to have any type of surgery, tell the surgeon ahead of time that you are taking diphenhydramine and magnesium salicylate. You may need to stop using the medicine for a short time.

Multum rt

Store this medicine at room temperature, away from heat, light, and moisture.

What happens if I miss a dose?

Since this medication is usually taken only at bedtime as needed, you are not likely to be on a daily dosing schedule. If you miss a dose or forget to take your medicine, wait until you are ready for sleep to take the medication. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Multum emt

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include stomach pain, diarrhea, blood in your urine, thirst, headache, buzzing in your ears, gasping for breath, confusion, hallucinations, blurred vision, or seizure (convulsions).

What should I avoid while taking diphenhydramine and magnesium salicylate?

Multum noalcohol

Avoid drinking alcohol while you are taking diphenhydramine and magnesium salicylate. Alcohol may increase your risk of stomach bleeding.

Multum dizzy

This medication can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid becoming overheated or dehydrated during exercise and in hot weather.

Multum donot

Do not use an over-the-counter cough, cold, allergy, or sleep medication without first asking your doctor or pharmacist. Diphenhydramine is contained in many medicines available over the counter. If you take certain products together you may accidentally take too diphenhydramine. Read the label of any other medicine you are using to see if it contains diphenhydramine or another antihistamine.

What are the possible side effects of diphenhydramine and magnesium salicylate?

Multum emt

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Multum emt

Stop using this medication and call your doctor at once if you have any of these serious side effects:

  • black, bloody, or tarry stools;
  • coughing up blood or vomit that looks like coffee grounds;
  • decreased hearing;
  • wheezing or trouble breathing;
  • seizure (convulsions);
  • urinating less than usual or not at all; or
  • nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

  • dry mouth;
  • mild nausea, indigestion, heartburn;
  • ringing in your ears;
  • skin rash or itching.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect diphenhydramine and magnesium salicylate?

Multum dizzy

Before using this medication, tell your doctor if you regularly use other medicines that make you sleepy (such as cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to sleepiness caused by diphenhydramine and magnesium salicylate.

Many drugs can interact with diphenhydramine and magnesium. Below is just a partial list. Tell your doctor if you are using:

  • methotrexate (Rheumatrex, Trexall);
  • antacids, or sodium bicarbonate (including baking soda);
  • a blood thinner such as warfarin (Coumadin);
  • gout medication such as probenecid (Benemid) or sulfinpyrazone (Anturane);
  • medication used to prevent blood clots, such as alteplase (Activase), clopidogrel (Plavix), dipyridamole (Persantine), urokinase (Abbokinase), and others.
  • pain medications such as acetaminophen (Tylenol), ibuprofen (Motrin, Advil), naproxen (Aleve, Naprosyn), diclofenac (Cataflam, Voltaren), etodolac (Lodine), indomethacin (Indocin), and others;
  • seizure medication such as phenytoin (Dilantin) or valproic acid (Depakene);
  • insulin or diabetes medications you take by mouth; or
  • an antibiotic such as ciprofloxacin (Cipro), enoxacin (Penetrex), itraconazole (Sporanox), ketoconazole (Nizoral), norfloxacin (Noroxin), ofloxacin (Floxin), plicamycin (Mithracin), tetracycline (Ala-Tet, Sumycin), or vancomycin (Vancocin);
Multum donot

There are many other medicines that can interact with diphenhydramine and magnesium salicylate. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor. Keep a list with you of all the medicines you use and show this list to any doctor or other healthcare provider who treats you.

Where can I get more information?

Your pharmacist can provide more information about diphenhydramine and magnesium salicylate.


Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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