Millions of people take some kind of heart medicine. Some people need several different medicines to strengthen their heart, lower cholesterol, prevent blood clots, or stabilize heart rhythms. They can be life giving—and powerful. Even a small drop in your blood pressure reading can cut your risk of having a heart attack.

At the same time, taking these medicines the wrong way or stopping them without first talking with your doctor could be dangerous. It could even be fatal.

Experts offer the following advice.

Keep a list of the medicines you take. This will help you stay on top of what you need to take and when. It's also important information to share with everyone on your health care team. Sharing this information will help make sure your care is managed safely and correctly.

Some people keep a list of their medicines on a computer so they can easily update it. You may also keep it on your smart phone. Record the name of the medicine, the dose, how often it's taken, and what the medicine is for. Keep a copy of this list in your wallet or purse. That way you'll always have it with you for doctors' appointments or in an emergency.

Think about what's easiest for you to remember. Taking your medicines every evening before brushing your teeth? Every morning with breakfast? Follow all medicine instructions. For example, statins are medicines that lower cholesterol. Some statins often work better taken before bed. This is because your body tends to make more cholesterol at night. A pill box can make keeping track a lot easier. Many people use a pill box with days of the week divided by times of day. This is very helpful if you take a lot of medicine. Some heart medicines can be dangerous if accidentally doubled or missed.

Check with your doctor or pharmacist before taking any new medicine. This might be a prescription or over-the-counter medicine. Or it might be a dietary supplement or an herbal product. Medicine interactions can cause problems. Often they can be serious.

For example, if you take the blood-thinner warfarin, using a medicine or other product that also thins your blood could put you at risk for a life-threatening stroke or internal bleeding.

Over-the-counter medicines can be especially hazardous:

• Decongestants that contain ephedrine can raise your blood pressure and cause heart rhythm problems.
• Migraine headache medicines can raise blood pressure. They can even bring on a heart attack in people with advanced heart disease.
• Weight-loss medicines may contain ephedrine. This medicine can increase blood pressure and heart rate. It can also causes heart rhythm problems.

Many pharmacists rely on a computer system that cross-checks your medicines with each new prescription. It automatically warns of possible medicine interactions. But if you buy a medicine elsewhere, it won't show up in the system.

Never stop taking a medicine without your doctor's OK. If price is an issue, ask your doctor if there's a lower-cost alternative.

If you suddenly stop taking beta-blockers, your heart rate and blood pressure can go up in the short term from a withdrawal effect. If you stop taking a medicine that keeps your heart rhythm stable or prevents blood clots, you could suffer a heart attack.

For the same reasons, never delay refilling a prescription.

Regular blood pressure checks can let you know if your medicine needs to be changed.

Call your doctor right away if you think you're having a side effect. They may be able to prescribe another medicine that can do just as good a job without the side effect. Call 911 if you have signs of a severe allergic reaction. These include trouble breathing, a new rash, a lot of swelling, or a lot of itching.

Get in the habit of measuring your blood pressure and heart rate on a regular basis. Many heart medicines can affect these vital signs. You may need to contact your doctor if your blood pressure or heart rate is too high or too low. Diuretics help your body get rid of extra fluid. If you take this type of medicine, weigh yourself every day.

Above all, don't let worries over the risks of these medicines keep you from taking them.

A printable medicine chart to help you keep track of your medicines is available on the FDA website. Search for My Medicine Record.