What are side effects? — Side effects are unintended or unwanted effects that medicines can cause. Most people take medicines without having side effects, but some people do have them.

Some of the more common side effects of medicines include:

��Nausea or vomiting

��Dizziness

��Headache

��Upset stomach, diarrhea, or constipation

��Increased or decreased appetite

��Trouble sleeping

��Dry mouth

��Dry cough that doesn’t go away

��Skin rashes

��Feeling tired or sleepy, or getting tired easily

��Feeling sad, depressed, anxious or jittery

��Sex problems

Can side effects be dangerous? — Yes, in rare cases, side effects can be dangerous or even life threatening. For example, people can have severe allergic reactions to medicines

Call an ambulance (in the US and Canada, dial 9-1-1) if you start a new medicine and develop any of the symptoms listed below:

��Wheezing or trouble breathing

��Chest tightness or pain

��Passing out or feeling as if you will pass out

��Swelling of your face, lips, tongue, or throat

��Seizures

When can side effects start? — If side effects are going to occur, they will usually start soon after you begin a new medicine or your dose is increased. Some side effects can occur immediately, such as an allergic reaction. Others might not start for a week or longer, such as rashes or stomach problems.

What should I do if my medicines cause side effects? — You should call your doctor or nurse any time you have a side effect that bothers you, but it’s especially important that you call right away if you start a new medicine and develop any of the symptoms listed below:

��Hives or rash (raised red welts on the skin that are usually itchy)

��Feeling confused or like you want to hurt or kill yourself

��Severe stomach ache, vomiting, diarrhea or no appetite

��Aches, pain, fever, weakness or no energy

��Dark color urine, black stools, yellowing of skin or eyes

��Symptoms that worry you

If you have other bothersome side effects, talk to your doctor. Do not simply stop taking the medicine that you think is causing the problem. The medicine might be very important for your health and well-being and stopping the medicine might cause other problems. Plus, it’s possible that what you think is a side effect is not actually a side effect at all.

Your doctor can help you figure out if the symptoms you are having are really side effects of your medicines or are caused by something else. If your symptoms are actually side effects, your doctor might be able to adjust your dose or switch you to a different medicine. There are often ways to help you feel better and more comfortable.

Even if the side effects you have can't be avoided, it's still important to talk to your doctor. He or she might be able to help you understand why the medicine you are taking is worth it even if it causes side effects.

Here are some things you should know or do to prevent or cope with side effects:

��Take medicine correctly to prevent side effects – Take the dose that is written on the prescription label (figure 1). This dose takes into account your age, weight, specific health problems, and the other medicines you take. Carefully follow all of the instructions on the label and printed patient education that comes with the medicine. (For example, some medicine labels say, “take with food,” or “avoid alcohol,” or “avoid driving until you know the effects of the medicine on you.”) Also, follow the instructions your doctor gives you verbally. He or she might tell you to start at a low dose and increase the dose gradually, so you don’t have side effects.

��Have your medicines checked to be sure you are taking them correctly – Bring a bag containing ALL your medicines with you to your doctor’s office. Have your doctor or nurse go over them with you.

��Be careful about mixing medicines – Some medicines do not mix well with other medicines or herbal remedies. Tell your doctor and pharmacist about ALL the medicines you take, including nonprescription medicines and herbal remedies. Have them check for drug interactions.

��Keep in mind that some side effects go away over time – As your body gets used to the medicine the side effect might go away. For example, medicines to treat depression can bother your stomach for a while but that side effect goes away after 1 or 2 weeks.

��Work with your doctor find ways to manage your side effects – There are usually simple things you can do to make side effects less bothersome. For example, some medicines can make you feel sleepy, but if you take them just before bed, the side effect is not a problem. Other medicines can make you constipated, but you can reduce constipation if you can eat more fiber, drink more water, and use a stool softener. If a blood pressure medicine or antidepressant causes sexual problems, you might be able to take another medicine to improve sex. The important thing is to talk to your doctor about any side effects that bother you. That way he or she can offer solutions. Not everyone has the same side effects, so your doctor won’t know what’s happening with you unless you tell him or her.

How can I find out the known side effects of my medicines? — There are a few different ways you can find this out:

��Ask your doctor or nurse what side effects to expect when he or she prescribes the medicines.

��Ask your pharmacist about the side effects when you get your prescriptions filled.

��Ask what you should do to avoid side effects and what to do if they occur.

��Read the printed patient education material that comes with the medicine.

��Check online at FDA.gov for information about the medicine.