What Is Acetaminophen and Phenylephrine?

The two drugs acetaminophen and phenylephrine often work together to relieve allergy, cold and flu symptoms. Both drugs are available separately and combined with other drugs in various cold and allergy medications. Acetaminophen is included in cold and flu medications due to the drug’s fever and pain reducing properties. Sometimes sold individually, phenylephrine is usually combined with other medications to treat nasal congestion arising from allergies and colds.

Acetaminophen is a widely used over-the-counter (OTC) drug that is sold worldwide. The drug is known by a variety of generic and brand names; and in many parts of the world the term paracetamol is used instead of acetaminophen. Some of the most recognized acetaminophen brand names through-out the world are Calpol®, Panadol™ and Tylenol®. Regardless of what name is used for acetaminophen, it will reduce fever and pain. This popular medication comes in various forms such as tablet, capsule and solution.

Phenylephrine is also available in OTC form as a nasal decongestant or as one of the main ingredients in cold, allergy and hay fever medications. The drug comes in many forms including pill, liquid and dissolvable tablets. Generally the medication is taken every four hours to continuously offer relief from nasal congestion.

While acetaminophen and phenylephrine offer relief from common allergy and cold symptoms, both medications can have serious side effects. Acetaminophen side effects include allergic reaction, hoarseness and difficulty breathing. Indicators of an allergic reaction include rash, hives and swelling. Taking more than the recommended dose can produce a host of serious side effects. Considering acetaminophen is primarily metabolized in the liver, an overdose can potentially result in liver damage.

Primary symptoms of possible liver toxicity due to an acetaminophen overdose include yellowing of the skin, abdominal pain and vomiting. To avoid liver damage N-acetylcysteine (NAC) is given within eight hours of an acetaminophen overdose. As with acetaminophen, people who take phenylephrine can also develop serious side effects. The primary side effect of phenylephrine is low blood pressure. Other less severe side effects include nervousness, dizziness and sleeplessness.

Caution should be taken in the presence of certain medical conditions to avoid adverse side effects when taking acetaminophen and phenylephrine. Those with phenylketonuria (PKU), which is an inherited metabolic disorder, should consult a doctor before taking acetaminophen and phenylephrine. Both medications’ variants may contain aspartame which is an artificial sweetener that cannot be metabolized by individuals with PKU. Other medical conditions that can produce serious side effects when taking both medications are liver disease and high blood pressure.