Quinidine
.svg)
Drug Status
Government Approvals
US(FDA)
WHO Essential Medicine
NO
Known Teratogen
No
Pharmaceutical Class
Antiarrhythmic and Cytochrome P450 2D6 Inhibitor
Controlled Drug Substance
No
Quinidine
Summary
Quinidine is used to treat and prevent abnormal heart rhythms such as atrial fibrillation and ventricular arrhythmias. It is also used to treat severe cases of malaria caused by the Plasmodium falciparum parasite.
Quinidine works by blocking sodium channels in the heart. This slows down the electrical conduction, helping to stabilize the heartbeat and reduce abnormal heart rhythms. It also has mild antimalarial properties.
For adults, the usual dose for treating atrial fibrillation ranges from 200-400 mg every 6-8 hours. The dose for life-threatening arrhythmias may be higher. Pediatric dosing is based on weight and must be determined by a doctor.
Common side effects of Quinidine include nausea, diarrhea, dizziness, and headache. Serious side effects can include irregular heartbeat, severe allergic reactions, or low blood pressure.
People with severe heart block, myasthenia gravis, or an allergy to Quinidine should avoid it. It should be used cautiously in those with kidney or liver disease. Quinidine can interact with other medications and supplements, so inform your doctor about all medications you take.
Indications and Purpose
How does Quinidine work?
Quinidine works by affecting the electrical activity of the heart to treat irregular heartbeats. It blocks certain electrical signals in the heart, helping to restore a normal rhythm. Think of it like adjusting the settings on a radio to reduce static and improve sound quality. By stabilizing the heart's electrical activity, Quinidine helps prevent abnormal heart rhythms. This makes it effective for treating conditions like atrial fibrillation, which is an irregular heartbeat. Always follow your doctor's instructions when using Quinidine to ensure effective treatment.
Is Quinidine effective?
Quinidine is effective for treating certain heart rhythm disorders, such as atrial fibrillation, which is an irregular and often rapid heart rate. It works by affecting the electrical activity of the heart to restore normal rhythm. Clinical studies support its effectiveness in managing these conditions. However, the effectiveness of Quinidine can vary based on individual health factors. Regular monitoring by your doctor is important to ensure the medication is working as intended. Always follow your doctor's instructions for using Quinidine to achieve the best results.
What is Quinidine?
Quinidine is a medication used to treat certain heart rhythm disorders, such as atrial fibrillation, which is an irregular heartbeat. It belongs to a class of drugs called antiarrhythmics, which work by affecting the electrical activity of the heart to restore normal rhythm. Quinidine is also used to treat malaria, which is a disease caused by parasites transmitted through mosquito bites. It can be used alone or in combination with other therapies, depending on the condition being treated. Always follow your doctor's instructions when using Quinidine.
Directions for Use
For how long do I take Quinidine?
Quinidine is usually taken long-term for managing chronic heart rhythm disorders. The duration of use depends on your specific condition and how well you respond to the medication. Your doctor will determine the appropriate length of treatment based on your health needs. It's important to take Quinidine exactly as prescribed and not to stop without consulting your doctor. Stopping Quinidine suddenly can worsen your condition. Always follow your doctor's instructions for taking Quinidine to ensure effective management of your heart rhythm disorder.
How do I dispose of Quinidine?
To dispose of Quinidine, take it to a drug take-back program or collection site at a pharmacy or hospital. They will dispose of it properly to prevent harm to people or the environment. If a take-back program isn't available, you can throw it in the trash at home. First, remove it from its original container, mix it with something undesirable like used coffee grounds, seal the mixture in a plastic bag, and throw it away. Always keep medications out of reach of children and pets.
How do I take Quinidine?
Take Quinidine exactly as your doctor prescribes. It's usually taken every 6 to 8 hours, depending on your condition. You can take it with or without food, but taking it with food might help prevent stomach upset. Swallow the tablets whole; do not crush or chew them. If you miss a dose, take it as soon as you remember unless it's almost time for your next dose. In that case, skip the missed dose and continue your regular schedule. Do not double up on doses. Always follow your doctor's specific instructions for taking Quinidine.
How long does it take for Quinidine to start working?
Quinidine starts working shortly after you take it, but the time to achieve its full therapeutic effect can vary. For heart rhythm disorders, you might notice improvements in symptoms like palpitations or dizziness within a few hours. However, it may take several days to see the full benefits. Factors like your overall health and the specific condition being treated can affect how quickly Quinidine works. Always take Quinidine exactly as prescribed and follow your doctor's instructions to achieve the best results.
How should I store Quinidine?
Store Quinidine at room temperature, away from moisture and light. Keep it in a tightly closed container to protect it from damage. Avoid storing it in humid places like bathrooms, where moisture can affect the medication's effectiveness. If your pills came in packaging that isn't child-resistant, transfer them to a container that children can't easily open. Always store Quinidine out of reach of children to prevent accidental ingestion. Regularly check the expiration date and properly dispose of any unused or expired medication.
What is the usual dose of Quinidine?
The usual starting dose of Quinidine for adults is 200 to 300 mg every 6 to 8 hours. Your doctor may adjust the dose based on your response and any side effects. The maximum recommended dose is typically 600 mg every 6 hours. Quinidine dosing may vary for different conditions, so always follow your doctor's specific instructions. For elderly patients or those with kidney or liver problems, dose adjustments may be necessary. It's important to take Quinidine exactly as prescribed to manage your condition effectively.
Warnings and Precautions
Can I take Quinidine with other prescription drugs?
Quinidine has several important drug interactions. It can interact with digoxin, which is a medication used to treat heart conditions, increasing the risk of digoxin toxicity. Quinidine can also interact with warfarin, which is a blood thinner, affecting its effectiveness. Other interactions include certain antibiotics and antifungal medications. These interactions can increase the risk of adverse effects or reduce the effectiveness of Quinidine. Always inform your doctor about all medications you are taking to prevent interactions. Your doctor can adjust your treatment plan to ensure safety and effectiveness.
Can Quinidine be taken safely while breastfeeding?
The safety of Quinidine while breastfeeding is not well-established. It's unclear if Quinidine passes into breast milk or affects the breastfed infant. If you're taking Quinidine and wish to breastfeed, discuss this with your doctor. They can help weigh the benefits and risks and may suggest alternative treatments if necessary. Your doctor can provide guidance on how to safely manage your condition while ensuring the well-being of your baby. Always consult your healthcare provider before making any changes to your medication.
Can Quinidine be taken safely while pregnant?
The safety of Quinidine during pregnancy is not well-established. Limited evidence makes it difficult to provide definitive advice. Quinidine should only be used during pregnancy if the benefits outweigh the risks. Uncontrolled heart rhythm problems can pose serious risks to both mother and baby. If you're pregnant or planning to become pregnant, discuss your treatment options with your doctor. They can help create a plan that ensures the safety of both you and your baby while managing your condition effectively.
Does Quinidine have adverse effects?
Yes, Quinidine can have adverse effects, which are unwanted reactions to a medication. Common adverse effects include nausea, vomiting, and diarrhea. These occur in about 10% of people taking Quinidine. Serious adverse effects include heart rhythm problems and low blood pressure, which require immediate medical attention. If you experience any new or worsening symptoms, contact your doctor. They can help determine if Quinidine is the cause and adjust your treatment if necessary. Always report adverse effects to your healthcare provider to ensure safe and effective treatment.
Does Quinidine have any safety warnings?
Yes, Quinidine has important safety warnings. It can cause serious heart rhythm problems, which is why it's crucial to follow your doctor's instructions closely. If you experience symptoms like dizziness, fainting, or a rapid heartbeat, seek medical help immediately. Quinidine can also lower blood pressure, leading to dizziness or fainting. Drink plenty of fluids and avoid standing up too quickly. Not adhering to these warnings can lead to severe complications. Always discuss any concerns with your doctor to ensure safe use of Quinidine.
Is it safe to drink alcohol while taking Quinidine?
It's best to avoid alcohol while taking Quinidine. Alcohol can increase the risk of side effects like dizziness and low blood pressure. It may also interfere with the effectiveness of Quinidine in treating heart rhythm problems. If you choose to drink, do so in moderation and be aware of any symptoms like dizziness or fainting. These could indicate a problem and require medical attention. Always discuss alcohol use with your doctor to get personalized advice based on your health situation.
Is it safe to exercise while taking Quinidine?
You can exercise while taking Quinidine, but be cautious. Quinidine can cause dizziness or low blood pressure, which might affect your ability to exercise safely. Start with light activities and gradually increase intensity as your body adjusts. Stay hydrated and avoid strenuous activities if you feel dizzy or lightheaded. If you experience any unusual symptoms during exercise, stop and rest. Always consult your doctor before starting a new exercise routine while on Quinidine to ensure it's safe for your specific health condition.
Is it safe to stop Quinidine?
It's not safe to stop Quinidine suddenly without consulting your doctor. Quinidine is often used for long-term management of heart rhythm problems. Stopping it abruptly can worsen your condition or cause serious heart rhythm issues. If you need to stop Quinidine, your doctor may suggest gradually reducing the dose to prevent complications. Always talk with your doctor before making any changes to your medication regimen. They can help you safely adjust your treatment plan to protect your health.
Is Quinidine addictive?
Quinidine is not addictive or habit-forming. It does not cause physical or psychological dependence. This medication works by affecting the heart's electrical activity to treat irregular heartbeats. It does not interact with brain chemistry in a way that would lead to addiction. You won't experience cravings or withdrawal symptoms when stopping Quinidine. If you have concerns about medication dependence, rest assured that Quinidine does not carry this risk. Always follow your doctor's instructions for taking and stopping this medication.
Is Quinidine safe for the elderly?
Elderly individuals are more vulnerable to the safety risks of Quinidine due to age-related changes in the body. These changes can affect how the body processes medication, increasing the risk of side effects like dizziness or low blood pressure. Quinidine can be used safely in the elderly with careful monitoring by a doctor. Regular check-ups are important to adjust the dose if needed and to monitor for any adverse effects. Always follow your doctor's instructions when taking Quinidine.
What are the most common side effects of Quinidine?
Side effects are unwanted reactions to a medication. Common side effects of Quinidine include nausea, vomiting, and diarrhea, affecting about 10% of users. Some people may also experience dizziness or lightheadedness. These side effects are usually mild and may improve as your body adjusts to the medication. If you notice new symptoms after starting Quinidine, they might be temporary or unrelated to the medication. Always talk with your doctor before stopping any medication. They can help determine if your symptoms are related to Quinidine and suggest ways to manage them.
Who should avoid taking Quinidine?
Quinidine has important contraindications. Do not use it if you have a history of Quinidine-induced low blood platelets, which are cells that help your blood clot, or if you have certain heart conditions like complete heart block without a pacemaker. These are absolute contraindications due to severe risks. Relative contraindications include liver or kidney disease, where caution is needed. Always inform your doctor of your medical history before starting Quinidine. They can determine if it's safe for you and monitor for any potential risks.
Forms / Brands
