Aspirin, dextromethorphan, doxylamine, and phenylephrine is a combination medicine used in adults and children at least 12 years old to temporarily relieve minor aches and pains, headaches, runny nose, sinus congestion and pressure, cough, sneezing, sore throat, nasal congestion, and fever caused by the common cold.

Aspirin, dextromethorphan, doxylamine, and phenylephrine may also be used for purposes not listed in this medication guide.

You should not use aspirin, dextromethorphan, doxylamine, and phenylephrine if you are allergic to it, or to any other pain reliever or fever reducer.

Do not use aspirin, dextromethorphan, doxylamine, and phenylephrine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine.

Using this medicine in a child or teenager with flu symptoms or chickenpox can cause a serious or fatal condition called Reye's syndrome.

Ask a doctor or pharmacist if this medicine is safe to use if you have or have ever had:

• stomach ulcers or bleeding problems;
• stomach problems such as heartburn;
• if you are age 60 or older;
• a habit of drinking more than 3 alcoholic beverages per day;
• high blood pressure, or heart disease;
• asthma;
• emphysema or chronic bronchitis;
• diabetes;
• thyroid disorder;
• glaucoma;
• cough with or without mucus;
• problems with urination;
• if you are on a low-salt diet; or
• liver or kidney disease.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Use Alka-Seltzer Plus Severe Cold Powerfast Fizz Day And Night (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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

Call your doctor at once if you have:

• severe sore throat that lasts for more than 2 days, or followed by fever, headache, rash, nausea, or vomiting.

Stop using this medicine and call your doctor at once if you have:

• stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
• stomach pain that does not go away;
• pain, cough, or nasal congestion that gets worse or lasts more than 7 days;
• fever that gets worse or lasts more than 3 days;
• redness or swelling;
• ringing in the ears or hearing loss;
• cough returns or occurs with rash or headache; or
• nervousness, dizziness, or sleep problems.

Less serious side effects may be more likely, and you may have none at all.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Drinking alcohol with this medicine can cause side effects.

Ask a doctor or pharmacist before taking other cough or cold medicines that may contain similar ingredients.

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.