Quinidine is used to treat certain types of irregular heartbeats. Quinidine is in a class of medications called antiarrhythmic medications. It works by making your heart more resistant to abnormal activity.

What is the action of quinidine?

Quinidine acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers.

What does quinidine do to the heart?

Quinidine is a Class 1a antiarrhythmic. It works in the heart to slow down the electrical impulses that make the heart muscle contract and pump blood. During an arrhythmia, heart muscle contractions are irregular. Slowing down the electrical impulses can regulate the heartbeat and stop the arrhythmia.

Is quinidine used for high blood pressure?

Quinidine had no significant effect on the systolic blood pressure response to any work load. However, quinidine significantly decreased the systolic blood pressure at all exercising heart rates, compared to control, in 15 of the 17 subjects.

How does quinidine prolong action potential?

Mechanism of action

Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (I_Na). ... The effect of quinidine on the ion channels is to prolong the cardiac action potential, thereby prolonging the QT interval on the surface ECG.

Quinidine uses and side effects - Explained simply, quinidine ecg

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Is quinidine still used?

Due to numerous proofs of increased risk for the appearance of ventricular arrhythmia and sudden death, as well as a number of other adverse effects and drug interactions, quinidine was withdrawn from use and in the recent years has become unavailable in many countries.

What is the difference between quinine and quinidine?

Quinidine is a secondary alcohol, the radicals in which are a 5-methyoxyquinoline ring and 3-vinylquinuclidine. Quinidine only differs from quinine in the configuration of the carbon atom of the carbinol group, and it can be made by isomerization of quinine (37.1. 1.47) [4].

When should I take quinidine?

Quinidine sulfate tablets are usually is taken every 6 hours. Extended-release quinidine gluconate tablets are usually is taken every 8 to 12 hours. Take quinidine at around the same times every day.

Can quinidine cause hypokalemia?

Hypokalemia and slow heart rates are commonly observed in a clinical setting and, in the tissue bath, quinidine and several of its metabolites induce abnormal automatic behavior when extracellular potassium is lowered and stimulation rate is slowed.

Can you drink alcohol with quinidine?

quiNIDine Alcohol (Ethanol)

Using dextromethorphan together with quiNIDine may increase the effects of dextromethorphan. Contact your doctor if you experience difficulty breathing, dizziness, drowsiness, anxiety, restless feeling, nervousness, confusion, or diarrhea.

Is quinidine a cardiac depressant?

The main use of quinidine, however, involves its activity as a myocardial depressant—that is, it depresses the excitability and conduction velocity of nerve impulses and the contractility of the heart muscle. The drug also tends to lower blood pressure.

Is quinidine an antimalarial?

Quinidine is an effective antimalarial drug for Plasmodium falciparum infections and may be more potent than quinine.

How does quinidine interact with digoxin?

An interaction between quinidine and digoxin is known to occur with toxic concentrations of digoxin in the serum resulting when the two drugs are administered together. The effects can be very dangerous, especially in those patients with advanced and severe cardiac disease.

Where is quinidine absorbed?

In conclusion, quinidine was rapidly and efficiently absorbed at the proximal intestine under ordinary circumstances. However, the oral bioavailability was modulated by various factors including the dose (or luminal concentration at the absorption site), presence of P-gp inhibitors, and gastrointestinal pH.

Is quinidine water soluble?

3Solubility. Slightly sol in water and soluble in alcohol.

In which drug reserpine is present?

reserpine, drug derived from the roots of certain species of the tropical plant Rauwolfia. The powdered whole root of the Indian shrub Rauwolfia serpentina historically had been used to treat snakebites, insomnia, hypertension (high blood pressure), and insanity.

What is quinidine arrhythmia?

Quinidine-Induced Arrhythmias

The lack of correlation between plasma quin- idine concentrations and this adverse drug effect raises the possibility either that external factors (for example, hypokalemia) modulate the response to quinidine in vivo or that one or more unmeasured active metabolites play a role.

What are the effects of low potassium and magnesium?

A harmful concentration of magnesium, sodium, potassium, or calcium can produce one or more of the following symptoms:

• irregular heartbeat.
• weakness.
• twitching and muscle spasms.
• changes in blood pressure.
• excessive tiredness.
• numbness.
• confusion.
• bone disorders.

What drugs contain quinidine?

Description and Brand Names

• Cardioquin.
• Quinaglute.
• Quinalan.
• Quinidex Extentabs.

What does dextromethorphan treat?

Dextromethorphan is used to temporarily relieve cough caused by the common cold, the flu, or other conditions. Dextromethorphan will relieve a cough but will not treat the cause of the cough or speed recovery. Dextromethorphan is in a class of medications called antitussives.

What is clofibrate used for?

Clofibrate is used to lower cholesterol and triglyceride (fat-like substances) levels in the blood.

Is quinidine a sodium channel blocker?

Quinidine is a “mixed” antiarrhythmic, with prominent sodium channel blocking (as well as potassium channel blocking) properties.

Why was quinine taken off the market?

In early 2007, FDA banned all prescription quinine products other than Qualaquin. FDA acted in this manner because of a perception that quinine is not effective for this condition and that its risk potential far exceeds its efficacy potential.

What is the therapeutic range for quinidine?

The generally accepted therapeutic range for quinidine is 2–6 μg/mL. Quinidine serum concentrations above the therapeutic range can cause increased QT interval or QRS complex widening (>35–50%) on the electrocardiogram, cinchonism, hypotension, high-degree atrioventricular block, and ventricular arrhythmias.

Why is quinine in tonic water bad for you?

The quinine in tonic water helps give it a bitter taste. People should not mistake tonic water for a healthful drink, as it may contain sugar and provides no additional nutritional value. Tonic water cannot help a person with leg cramps or restless legs syndrome.