• Basic Info
• Top Questions
• Clinical Info
• Interactions

Before taking quinidine, tell your doctor if you are taking any of the following medicines:

• pimozide (Orap);

• itraconazole (Sporanox);

• ziprasidone (Geodon);

• voriconazole (VFEND);

• thioridazine (Mellaril) or mesoridazine (Serentil);

• ritonavir (Norvir);

• dolasetron (Anzemet);

• digoxin (Lanoxin);

• warfarin (Coumadin);

• erythromycin (E-Mycin, Eryc, E.E.S., others);

• sparfloxacin (Zagam), levofloxacin (Levaquin), grepafloxacin (Raxar), gatifloxacin (Tequin);

• another medicine to treat irregular heartbeats such as bepridil (Vascor), dofetilide (Tikosyn), procainamide (Procan SR, Procanbid, Pronestyl), disopyramide (Norpace), and others;

• a beta-blocker such as atenolol (Tenormin), metoprolol (Lopressor), propranolol (Inderal), and others;

• a tricyclic antidepressant such as amitriptyline (Elavil), doxepin (Sinequan), clomipramine (Anafranil), imipramine (Tofranil), others; or

• a phenothiazine such as chlorpromazine (Thorazine), promethazine (Phenergan, Promethegan), prochlorperazine (Compazine), and others.

You may not be able to take quinidine, or you may require a dosage adjustment or special monitoring if you are taking any of the medicines listed above.

Many drugs other than those listed here can interact with quinidine, resulting in dangerous side effects and/or decreased effectiveness. Do not take any other prescription or over-the-counter medications, including herbal products, during treatment with quinidine without first talking to your doctor or pharmacist.

If you experience any of the following serious side effects, stop taking quinidine and seek emergency medical attention or contact your doctor immediately:

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);

• a new or a worsening irregular heartbeat pattern;

• chest pain or chest discomfort;

• ringing in the ears;

• changes in vision;

• dizziness, fainting, or headache;

• rash;

• difficulty breathing;

• abdominal pain, nausea, or vomiting; or

• yellowing of the skin or eyes.

Other, less serious side effects may be more likely to occur. Continue to take quinidine and talk to your doctor if you experience

• mild upset stomach;

• headache;

• decreased appetite;

• diarrhea; or

• muscle weakness.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.