Background

Cinchona (Cinchona calisaya) is an evergreen tree that grows up to 15 meters in Peru, Ecuador, and Colombia. The bark is used to make medicine.

Cinchona bark contains a chemical called quinine. Quinine has effects that help fight malaria and reduce heart palpitations.

People use cinchona for cancer, hemorrhoids, malaria, muscle cramps, varicose veins, and many other conditions, but there is no good scientific evidence to support these uses.

Safety Safety definitions

When taken by mouth: Cinchona is likely safe when used as a flavoring in tonic water and alcoholic beverages. But it is possibly unsafe when used as medicine. Cinchona products sold as over-the-counter (OTC) medicines are required to carry the warning, "Caution - discontinue use if ringing in the ears, deafness, skin rash, or visual disturbances occur." Cinchona contains quinine, which was banned by the US FDA due to serious side effects. In large amounts, cinchona is likely unsafe and has been linked to fatal heart complications.

Special Precautions & Warnings:

Pregnancy: Cinchona is likely unsafe when taken by mouth during pregnancy. It might stimulate the uterus and cause birth defects. Avoid use.

Breast-feeding: Cinchona is possibly unsafe when taken by mouth while breast-feeding. Chemicals in chinchona can be passed to a nursing infant in breastmilk and cause toxic effects. Avoid use.

Stomach or intestinal ulcers: Don't use cinchona if you have ulcers. It might increase the risk of bleeding.

Heart conditions such as long QT interval syndrome: Cinchona contains quinine and quinidine. These chemicals can cause an irregular heartbeat and might increase the risk of irregular heartbeat in people with long QT syndrome.

Myasthenia Gravis: Don't use cinchona if you have myasthenia gravis. It contains quinine and quinidine, which might cause muscle weakness and make this condition worse.

Surgery: Cinchona might slow blood clotting. This might increase the risk of extra bleeding during and after surgery. Stop using cinchona at least 2 weeks before a scheduled surgery.

Effectiveness

Dosing & administration

Traditionally, cinchona has been prepared as a tea. But there isn't enough reliable information to know what an appropriate dose of cinchona might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.

Interactions with pharmaceuticals

Antacids

Interaction Rating=Moderate Be cautious with this combination.

Antacids are used to decrease stomach acid. Cinchona may increase stomach acid. By increasing stomach acid, cinchona might decrease the effectiveness of antacids. Also, cinchona contains quinidine and some antacids might slow down removal of quinidine from the body, increasing the risk of side effects.

Carbamazepine (Tegretol)

Interaction Rating=Moderate Be cautious with this combination.

The body breaks down carbamazepine to get rid of it. Cinchona contains quinine. Quinine can increase how much carbamazepine the body absorbs. Taking cinchona along with carbamazepine might increase the effects and side effects of carbamazepine.

Digoxin (Lanoxin)

Interaction Rating=Moderate Be cautious with this combination.

Cinchona contains quinine and quinidine, which can slow the rate at which digoxin is removed from the body. Taking cinchona along with digoxin might increase the effects and side effects of digoxin.

Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates)

Interaction Rating=Moderate Be cautious with this combination.

Some medications are changed and broken down by the liver. Cinchona might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

Medications that can cause an irregular heartbeat (QT interval-prolonging drugs)

Interaction Rating=Moderate Be cautious with this combination.

Cinchona might affect electrical currents in the heart. This can increase the risk of having an irregular heartbeat. Some medications can have this same effect. Taking cinchona with these medications might increase the risk for a serious heart issue.

Medications that decrease stomach acid (H2-blockers)

Interaction Rating=Minor Be watchful with this combination.

H2-blockers are used to decrease stomach acid. Cinchona can increase stomach acid. Taking cinchona might decrease the effects of H2-blockers.

Some common H2-blockers include cimetidine (Tagamet), ranitidine (Zantac), and famotidine (Pepcid).

Medications that decrease stomach acid (Proton pump inhibitors)

Interaction Rating=Minor Be watchful with this combination.

Proton pump inhibitors are used to decrease stomach acid. Cinchona can increase stomach acid. Taking cinchona might decrease the effects of proton pump inhibitors.

Some common proton pump inhibitors include omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), and esomeprazole (Nexium).

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)

Interaction Rating=Moderate Be cautious with this combination.

Cinchona might slow blood clotting. Taking cinchona along with medications that also slow blood clotting might increase the risk of bruising and bleeding.

Phenobarbital (Luminal)

Interaction Rating=Moderate Be cautious with this combination.

Cinchona contains quinine. Quinine might increase how much phenobarbital is in the body. Taking cinchona with phenobarbital might increase the effects and side effects of phenobarbital.

Quinidine

Interaction Rating=Major Do not take this combination.

Cinchona contains quinidine. Taking quinidine along with cinchona can increase the effects and side effects of quinidine. Do not take cinchona if you are taking quinidine.

Quinine

Interaction Rating=Major Do not take this combination.

Cinchona contains quinine. Taking quinine along with cinchona can increase the effects and side effects of quinine. Do not take cinchona if you are taking quinine.

Interactions with herbs & supplements

Herbs and supplements that might cause an irregular heartbeat (QT interval-prolonging products): Cinchona might affect electrical currents in the heart. This can increase the risk of having an irregular heartbeat. Taking cinchona with other supplements with similar effects might increase the risk for a serious heart issue. Examples of supplements with this effect include bitter orange, ephedra, grapefruit, iboga, and Panax ginseng.
Herbs and supplements that might slow blood clotting: Cinchona might slow blood clotting and increase the risk of bleeding. Taking it with other supplements with similar effects might increase the risk of bleeding in some people. Examples of supplements with this effect include garlic, ginger, ginkgo, nattokinase, and Panax ginseng.

Interactions with foods

There are no known interactions with foods.