What is Quinine: Uses, Dosage, Side Effects and More

Quinine is a prescription medication that comes from the bark of the cinchona tree and has been used for centuries to treat malaria. Today, doctors primarily prescribe it for severe malaria cases when other treatments haven't worked or aren't suitable. You might also know quinine from tonic water, though the medical form is much stronger and requires careful monitoring by your healthcare provider.

What is Quinine?

Quinine is a natural alkaloid that fights malaria parasites in your blood. It's one of the oldest antimalarial drugs we have, originally discovered by indigenous peoples in South America who used cinchona bark to treat fevers. The medication works by interfering with the malaria parasite's ability to break down hemoglobin, essentially starving the parasite.

In its medical form, quinine is much more concentrated than what you'd find in tonic water. Your doctor will only prescribe it when they believe the benefits outweigh the risks, as it can have serious side effects that need monitoring.

What is Quinine Used For?

Doctors prescribe quinine primarily for severe malaria caused by Plasmodium falciparum parasites. This is typically when you've traveled to areas where malaria is resistant to other treatments, or when first-line medications haven't worked for you. It's considered a second-line treatment, meaning your doctor will try other options first.

Sometimes, though much less commonly, doctors might prescribe quinine for severe leg cramps that haven't responded to other treatments. However, this use has become controversial due to safety concerns, and most medical organizations now recommend against it for cramps.

How Does Quinine Work?

Quinine targets the malaria parasite's digestive system inside your red blood cells. When malaria parasites infect your blood, they feed on hemoglobin and produce toxic waste products. Quinine disrupts this process by interfering with the parasite's ability to detoxify these waste products, ultimately killing the parasite.

This is a fairly strong medication that works differently from newer antimalarial drugs. While effective, it requires careful dosing and monitoring because it can affect your heart rhythm and other body systems. Your doctor will want to keep a close eye on you while you're taking it.

How Should I Take Quinine?

Take quinine exactly as your doctor prescribes, usually every 8 hours with food or milk to reduce stomach upset. Swallow the capsules or tablets whole with a full glass of water, and don't crush or chew them as this can increase the risk of side effects.

Food helps your body absorb the medication more evenly and reduces nausea, which is a common side effect. Try to take it at the same times each day to maintain steady levels in your bloodstream. If you're having trouble keeping it down due to nausea, let your doctor know right away.

Never adjust your dose on your own, even if you're feeling better. Malaria parasites can develop resistance if you don't complete the full course, and stopping early might allow the infection to return stronger than before.

How Long Should I Take Quinine For?

Most people take quinine for 3 to 7 days, depending on the severity of their malaria and how well they respond to treatment. Your doctor will determine the exact duration based on your specific situation, including which type of malaria you have and where you likely contracted it.

It's crucial to complete the entire course even if you start feeling better after a few days. Malaria parasites can hide in your system, and stopping treatment early gives them a chance to multiply again. Your doctor might also prescribe additional medications to take alongside or after quinine to ensure all parasites are eliminated.

What Are the Side Effects of Quinine?

Quinine can cause several side effects, ranging from mild to serious. The most common ones you might experience include nausea, vomiting, diarrhea, and stomach pain. Many people also develop what's called "cinchonism," which includes symptoms like ringing in your ears, headache, dizziness, and temporary hearing problems.

Here are the more common side effects you should be aware of:

• Nausea and vomiting
• Diarrhea or stomach upset
• Headache and dizziness
• Ringing in your ears (tinnitus)
• Temporary hearing changes
• Blurred vision
• Flushing or sweating

Most of these symptoms are manageable and often improve as your body adjusts to the medication. However, they're also signs that you need close monitoring from your healthcare team.

More serious side effects require immediate medical attention. These include severe heart rhythm problems, significant drops in blood sugar, severe allergic reactions, and blood disorders. While less common, these can be life-threatening.

Contact your doctor immediately if you experience:

• Irregular or fast heartbeat
• Severe dizziness or fainting
• Signs of low blood sugar (sweating, shakiness, confusion)
• Severe rash or difficulty breathing
• Unusual bleeding or bruising
• Severe vision or hearing changes

These serious reactions are rare but need prompt medical care. Your doctor will likely monitor your heart rhythm and blood sugar levels while you're taking quinine, especially if you have other health conditions.

Who Should Not Take Quinine?

Quinine isn't safe for everyone, and your doctor will carefully review your medical history before prescribing it. People with certain heart conditions, blood disorders, or those taking specific medications may need alternative treatments instead.

You should not take quinine if you have:

• A history of severe allergic reactions to quinine or quinidine
• Certain heart rhythm disorders
• A condition called glucose-6-phosphate dehydrogenase (G6PD) deficiency
• Myasthenia gravis (a muscle weakness disorder)
• Severe kidney or liver disease

Your doctor will also be cautious about prescribing quinine if you're pregnant, breastfeeding, or have diabetes. While it can be used in pregnancy when the benefits outweigh the risks, it requires very careful monitoring.

Make sure to tell your doctor about all medications you're taking, including over-the-counter drugs and supplements. Quinine can interact with many medications, including blood thinners, heart medications, and certain antibiotics.

Quinine Brand Names

Quinine is available under several brand names, with Qualaquin being the most common prescription form in the United States. Other brand names include Quinamm, though availability can vary by country and region.

Generic quinine is also available and works just as effectively as brand-name versions. Your pharmacist can help you understand which form you're receiving and ensure you're taking it correctly. Always check that you're getting the prescription strength, not the much weaker form found in tonic water.

Quinine Alternatives

Several alternatives to quinine exist for treating malaria, and your doctor will often try these first. Artemisinin-based combination therapies (ACTs) are now the preferred first-line treatment for most types of malaria because they're often more effective and have fewer side effects.

Common alternatives include:

• Artemether-lumefantrine (Coartem)
• Atovaquone-proguanil (Malarone)
• Doxycycline
• Mefloquine
• Chloroquine (for areas without resistance)

Your doctor will choose the best alternative based on where you contracted malaria, which type of parasite you have, and your individual health factors. In some cases, you might receive a combination of medications to ensure the most effective treatment.

Is Quinine Better Than Chloroquine?

Quinine and chloroquine work differently and are used in different situations, so it's not simply a matter of one being better than the other. Chloroquine used to be the go-to treatment for malaria, but many malaria parasites have developed resistance to it, especially in certain parts of the world.

Quinine is typically reserved for severe malaria cases or areas where other treatments have failed due to resistance. It's considered more potent but also has more significant side effects and requires closer monitoring. Chloroquine, when it works, tends to be better tolerated with fewer side effects.

Your doctor will choose based on several factors including where you likely contracted malaria, local resistance patterns, and your overall health. In many cases, neither of these medications will be the first choice, as newer combination therapies are often more effective.