Before taking quinine, tell your doctor or pharmacist if you are allergic to it; or to quinidine or mefloquine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: previous serious side effects with quinine (such as blood problems), family/personal history of a certain enzyme problem (glucose-6-phosphate dehydrogenase deficiency-G6PD), a certain eye nerve problem (optic neuritis), hearing problems (such as ringing in the ears), a certain nerve/muscle disease (myasthenia gravis), heart rhythm problems (such as atrial fibrillation/flutter), kidney problems, liver problems.
This drug may make you dizzy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Quinine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.