Quinidine is one of the oldest antiarrhythmic medications, but isn't used as often these days since there are better alternatives.
Quinidine is an antiarrhythmic. It works by blocking sodium channels, which play a major part in your heart's electrical activity. It slows down abnormal electricity in your heart in order to treat or prevent abnormal rhythms.
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Contact your healthcare provider immediately if you experience any of the following.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Less common
Abdominal pain and/or yellow eyes or skin
blurred and/or double vision, confusion, delirium, disturbed color perception, headache, noises or ringing in the ear, and/or visual intolerance of light
dizziness or lightheadedness
fainting
Rare
Chest pain, fever, general discomfort, joint pain, joint swelling, muscle pain, and/or skin rash
nosebleeds or bleeding gums
unusual tiredness or weakness and/or pale skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Quinidine doesn't belong to the class of medications called beta-blockers (medications that end in -lol such as metoprolol (Lopressor) or carvedilol (Coreg)). It doesn't have any beta-blocking effects. Some people may need to take this medication in combination with a beta-blocker.
Quinidine isn't used very much these days for arrhythmias (abnormal heart rhythms). It's a very old drug with many potential side effects, and there are usually better alternatives available. Quinidine can still be helpful in certain situations, though; for example, it's a preferred medication for treating Brugada Synrdome, a rare type of arrhythmia. Your heart specialist will determine if this medication is right for you based on your specific condition and other medical problems. Quinidine is also one of the main ingredients in Nuedexta (dextromethorphan/quinidine), which is used to treat a condition called pseudobulbar affect.
Quinidine is the generic name of this medication. It's available as quinidine sulfate tablets and quinidine gluconate extended-release tablets. Quinidine used to come in various brand-names such as Cardioquin, Cin-Quin, and Quinidex, but those are no longer available. Currently, quinidine is only available as a generic form.
The chemical structures of quinine and quinidine are very similar. Quinine (Qualaquin) is primarily used to treat malaria infections, while quinidine is used for abnormal heart rhythms (arrhythmias).
Quinidine can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Some studies have shown that people who took quinidine for abnormal heart rhythms (arrhythmias) that were not life-threatening had a greater risk of dying, compared to those who took a placebo or other antiarrhythmic. Your prescriber should give you quinidine only for life-threatening arrhythmias and only when absolutely necessary.
Antiarrhythmic medications like quinidine can cause new or worsened arrhythmia, including rhythms that are too fast or too slow. Many of these conditions are life-threatening, so you should only take this medication if you have a serious heart condition and if you are able to follow-up with your provider regularly to monitor your heart health. You will get an EKG (test of your heart's electrical activity) on a regular basis to make sure the quinidine is working as it should. If your electrolyte levels are low, you may need to take supplements. If you ever experience chest discomfort, dizziness, fainting, or fast heartbeat while you are on quinidine, get medical help right away.
Poor liver or kidney function, heart failure, and certain medications can cause quinidine levels in the body to be higher, leading to more side effects. On the other hand, some medications can cause quinidine levels to be too low, making it not work as well. If you have any of these risk factors, your provider may check lab and heart tests more frequently to be safe. Be sure to talk to your providers, including your pharmacist, about all the medications you are taking.
Many medications can affect the levels of quinidine in the body. At the same time, quinidine can also also cause problems with other medications by affecting their levels or making them work more strongly. Be sure to talk to your providers, including your pharmacist, about all the medications you are taking. While you are on quinidine, don't start or change your medications without first talking with your provider or pharmacist.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.