Many of the products that treat cold symptoms are available over-the-counter (which means you can get them without a prescription from your doctor). While these products can be safe and effective, they can also interact with other kinds of medicine. Prescription medications that treat mental health conditions such as depression, anxiety, or bipolar disorder are among the most common types of drugs that can interact with common cold medicines. Here’s what you need to know about using OTC cold and flu remedies if you take antidepressants.

What Are Medication Interactions?

Knowing how different drugs interact is not just important to your safety but it also matters in terms of making sure that your medications work the way they were intended. Even if an interaction is not dangerous, it can still cause problems (like when one drug makes another less effective). On the other hand, certain medications are sometimes combined on purpose because they work well together or have a positive effect on one another.

Pharmacokinetic and Pharmacodynamic Interactions

Drug interactions can be pharmacokinetic or pharmacodynamic.

Pharmacokinetic interaction: In this instance, when two medications are taken together, the interaction can change how one (or both) work. For example, taking certain medications at the same time might affect how the body absorbs, uses, or eliminates one (or both) drugs. When different medications are taken together, it might increase or decrease how much of the medicine is in your body. Pharmacodynamic interactions: These interactions occur when medicines directly affect each other. For example, taking more than one medication that causes sedation will make the effect more intense (potentiate). Pharmacodynamic interactions also occur when a drug is taken with a substance like alcohol.

Certain ingredients in cold medicine can change how antidepressants work, including making them less effective. They can also exacerbate side effects or cause new side effects.

Cold Medicine and Antidepressants

Cold and flu remedies that are available over-the-counter often contain ingredients like pseudoephedrine (decongestant), diphenhydramine (antihistamine), dextromethorphan (cough suppressant), or guaifenesin (expectorant). These substances can interact with prescription medications used to treat depression and other mental health conditions and have the potential to be serious. There are several classes of drugs that are used to treat psychiatric conditions, including antidepressants, antipsychotics, tranquilizers, and anticonvulsants.

Antipsychotics, Tranquilizers, and Sedatives

Some OTC cold remedies have ingredients that can make you feel sleepy. If you have a bad cough that’s been keeping you awake at night, that can be helpful. However, certain antipsychotics and tranquilizers also have sedative effects. If you take these drugs with cough medicine, some decongestants, or an antihistamine, the sedating effect can be intensified. If you are taking any prescription medication, always check with your doctor or pharmacist before you take any over-the-counter medication or supplement.

Antidepressants and DXM

It is especially important that you do not use any medicine with dextromethorphan if you take a selective serotonin reuptake inhibitor (SSRI) such as Prozac (fluoxetine), Zoloft (sertraline), or Lexapro (escitalopram). The combination can cause a serious interaction called serotonin syndrome. Like other antidepressants, monoamine oxidase inhibitors (MAOIs) can also interact with other medications, remedies, or supplements you might be taking—they can even interact with food. If you take an MAOI, you should not take cold, flu, or cough medicine that contains a decongestant (such as phenylephrine and pseudoephedrine) or dextromethorphan. Nasal decongestant sprays are also not safe to use if you are taking an MAOI.

Antidepressants and NSAIDs

Cold and flu preparations sometimes include a non-steroidal anti-inflammatory drug (NSAID) like ibuprofen or acetaminophen as a pain reliever or fever reducer. NSAIDs can increase your risk of gastrointestinal (GI) bleeding. A 2015 study found that people who took SSRIs and NSAIDs (naproxen and aspirin, in addition to ibuprofen) together also appeared to be at an increased risk for bleeding in the brain (intracranial hemorrhage) in the month after they took the combination.

What to Do When You Get Sick

If you find yourself down and out with a bad cold or seasonal flu, there are some things you’ll want to keep in mind as you’re trying to get better.

Keep Taking Your Medications

Unless your doctor tells you to discontinue, you should never stop taking a medication that has been prescribed for you—including antidepressants or other drugs used to treat a mental health condition. The symptoms of stopping your medication can be severe—even life-threatening. For example, if a person who is taking a selective serotonin reuptake inhibitor (SSRI) to treat depression needs or wants to stop taking the medication, they will usually need to slowly taper their dose to reduce the risk of SSRI discontinuation syndrome. Another reason to continue taking your medication even if you don’t feel well is to help ensure that you don’t make yourself feel worse. If you take an antidepressant to manage depression, stopping it could cause your depression symptoms to come back. You would not want this to happen in the best of times, let alone when you are already not feeling well.

Take Care of Your Mind and Body

When you’re sick, you need to take care of your mind as well as your body. When your reserves are diminished because you are trying to heal from a physical illness or infection, your mental health might also feel a little sensitive. When you’re sick, there are also things you can do to help yourself get better that are non-pharmaceutical. While they might seem obvious, it’s easy to forget to take good care of yourself when you are healthy—let alone when you’re not feeling well.

Eat and Drink Well

When you’re feeling sick, you might not have much of an appetite or even feel sick to your stomach. Sticking to nutritious, simple, easy-to-digest foods will help keep your strength up without making your symptoms worse (there’s a reason your Grandma’s chicken soup has such a good reputation!). You also need to drink plenty of fluids. Water is usually the most effective way to replenish, but there are a couple of exceptions:

If you have symptoms like vomiting or diarrhea (which can make you more likely to become dehydrated), you might want to try sipping a low-sugar sports drink to replenish electrolytes.When you have a sore throat, hot tea with honey can be soothing as well as hydrating.You don’t want to drink it, but gargling with salt water might also help reduce the pain of a sore throat.

Take a Sick Day

Though you might feel stressed out at the thought of missing work or going back to bed for the day, one of the best things that you can do when you are sick is get plenty of rest. Taking it easy (even having a nap) can help ease your symptoms (especially if you have a cough that’s keeping you up all night) and gives your body the rest that it needs to heal. Resting up on the couch or in bed can also help prevent you from feeling (or getting) sicker. When your immune system is trying to fight off an illness, you’re likely to feel extra tired and you’re also more vulnerable to other infections.