Introduction

Phenylephrine is a decongestant used for short-term relief of nasal congestion from the common cold, sinusitis, upper respiratory allergies, or hay fever. Phenylephrine is found in several different over-the-counter medications. If you’re pregnant, you’re probably wary of taking many drugs. But what happens if you get a cold or have allergies — can you take a drug like phenylephrine to feel better?

Effects of phenylephrine on pregnancy

Phenylephrine may not be the best choice during pregnancy, especially for women in their first trimester. This is because phenylephrine may cause harm such as birth defects. However, the form of phenylephrine that you use can make a difference.

Get answers: What happens during the trimesters of pregnancy? »

Research suggests that phenylephrine that’s taken by mouth is not safe for pregnant women. This is because of the way phenylephrine works. The drug relieves nasal congestion by narrowing the blood vessels in your nasal passages. This reduces the secretions in the nasal passages and opens up the airways. However, for oral phenylephrine, this narrowing of blood vessels is not limited to the nasal passages. It also affects the blood vessels in your uterus. Any narrowing of uterine blood vessels during pregnancy may decrease the blood flow to the fetus. And decreased blood flow can prevent the fetus from getting enough oxygen, which can cause birth defects or make the baby’s heart beat too slowly. Because of this risk, you should not take oral phenylephrine during pregnancy.

On the other hand, intranasal phenylephrine mostly affects just the nasal passages. You take an intranasal drug directly into the nose, typically by a spray. In general, intranasal decongestants should only be used for three days at a time. There is no known link between short-term use of intranasal phenylephrine and birth defects or other harm to a pregnancy.

However, if you’re pregnant, you should be sure to talk to your doctor before using either form of phenylephrine.

Drug interactions

Oral phenylephrine can interact with some medications that a pregnant woman may be given before, during, and after labor. Oxytocics and ergot derivatives are two classes of these medications. These drugs are used for things such as managing labor and treating postpartum bleeding. Taking these drugs while also taking phenylephrine by mouth can increase blood pressure in the mother, which can cause pregnancy complications or cause the baby to be born too early. These effects are not linked with use of intranasal forms of phenylephrine, however.

Side effects of phenylephrine

Phenylephrine may cause some side effects. These are important to consider during pregnancy when your comfort and your baby’s health are primary concerns. Some of the side effects may go away as your body gets used to the medication. If any of these side effects cause problems for you or don’t go away, call your doctor.

The more common side effects of phenylephrine can include:

  • nervousness
  • dizziness
  • trouble sleeping
  • burning, stinging, or sneezing right after you use the nasal spray

Serious side effects are usually caused by swallowing the intranasal product by accident. Some serious side effects can include:

  • nausea
  • vomiting
  • drooling
  • increased temperature
  • tiredness
  • coma

OTC drugs containing phenylephrine

Many over-the-counter (OTC) medications contain phenylephrine. Because of the risks during pregnancy, you should know which products contain this ingredient so you can avoid them as needed. Examples of oral drugs that contain phenylephrine include:

  • Sudafed PE (all versions)
  • Tylenol Sinus + Headache
  • Contac Cold + Flu
  • Mucinex Fast-Max Cold, Flu & Sore Throat

Examples of intranasal drugs that contain phenylephrine include:

  • Neo-Synephrine (all versions)
  • 4 Way

There are also many generic-version products that contain phenylephrine. These products may combine phenylephrine with other drugs such as guaifenesin (which loosens mucus) and dextromethorphan (a cough suppressant). Be sure to read the labels of any OTC medications you take so you know exactly what drugs you’re using.

Alternative treatments

Symptoms of nasal congestion due to the common cold or allergies can be uncomfortable and unpleasant, but they’re not life-threatening. And over time, they generally go away on their own. For these reasons, many doctors suggest non-drug treatment for nasal congestion during pregnancy. Some options include:

  • increased fluid intake: helps flush cold viruses out of the body
  • rest: helps the body fight off illness
  • hot showers or vaporizers: provide steam to help clear nasal passages
  • humidifiers: add moisture to the air and help your sinuses drain

Read more: Treating a cold or flu when pregnant »

Talk with your doctor

If you’re pregnant, it’s wise to be careful about which medications you take. The following steps can help:

  • Talk with your doctor before taking any medications. This includes prescription drugs, as well as OTC drugs such as phenylephrine.
  • Carefully read the product labels of any cough and cold medications you may want to use. Some of these products may contain phenylephrine or other drugs that may not be safe during pregnancy.
  • Talk with your doctor if your congestion or other symptoms last longer than a few days. Extended symptoms may mean you have a more serious issue.

Working with your doctor can help you treat your congestion symptoms while keeping your pregnancy safe.

Q:

What’s the difference between phenylephrine and pseudoephedrine?

A:

Both of these drugs are decongestants. Because they do the same thing, they’re not used together in combination medications. However, they are used in different forms of Sudafed. For instance, Sudafed Congestion contains pseudoephedrine, but Sudafed PE Congestion contains phenylephrine. Pseudoephedrine can be made into illegal methamphetamine, a highly addictive drug. Because of this, U.S. law dictates that Sudafed can only be purchased directly from pharmacy staff. That’s why you can’t find regular Sudafed on the pharmacy shelf, but you can find Sudafed PE there.

Healthline Medical TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.