Clozaril and Pronestyl

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Using procainamide together with cloZAPine is not recommended. Combining these medications may increase the risk of agranulocytosis, which is a rare but serious and potentially fatal disorder that affects white blood cells, as well as an irregular heart rhythm that may also be life-threatening in severe cases. Contact your doctor if you develop signs and symptoms of infection such as fever, chills, body aches, sore throat, coughing, breathing difficulties, mouth ulcers, or flu-like symptoms during treatment with either medication. In addition, you should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, shortness of breath, or irregular heartbeat. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

CONTRAINDICATED: The use of clozapine with other potentially myelotoxic agents including procainamide may increase the risk and/or severity of hematologic toxicity. Clozapine alone is associated with a significant risk of agranulocytosis, defined as an absolute neutrophil count (ANC) of less than 500/mm3. During premarketing trials in the U.S., at a time when the need for close monitoring of white blood cell counts was already recognized, the cumulative incidence of agranulocytosis at one year was estimated to be approximately 1.3%. The incidence has decreased postmarketing under a weekly WBC count monitoring system. Although the mechanism of clozapine-induced agranulocytosis is unknown, it is possible that causative factors may interact synergistically to increase the risk and/or severity of bone marrow suppression. The use of procainamide itself has been associated with agranulocytosis, bone marrow depression, neutropenia, hypoplastic anemia, and thrombocytopenia in approximately 0.5% of patients. A fatality rate of 3% has been reported for agranulocytosis associated with clozapine and 20% to 25% for agranulocytosis associated with procainamide.

GENERALLY AVOID: Like other Class IA antiarrhythmic agents, procainamide can cause dose-related prolongation of the QT interval. Theoretically, coadministration with other agents that can prolong the QT interval such as clozapine may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: The use of clozapine in combination with other agents having a well-known potential to cause agranulocytosis or otherwise suppress bone marrow function is considered contraindicated. The concurrent use of procainamide with other medications that can prolong the QT interval should preferably be avoided unless benefits are anticipated to outweigh the risks.

Clozaril

Generic Name: clozapine

Brand name: Clozaril, Fazaclo, Versacloz, Clopine, CloZAPine Synthon, Denzapine, Zaponex

Synonyms: n.a.

What is Clozaril?

Pronestyl

Generic Name: procainamide

Brand name: Pronestyl, Procan SR, Pronestyl-SR, Procanbid

Synonyms: Pronestyl (injection)

What is Pronestyl?