Procainamide drug monitoring

The cardiac arrhythmias are life-threatening, so the patient must be closely monitored, with facilities available for possible resuscitation. Drugs such as quinidine and procainamide are contraindicated, but lidocaine, propranolol, or phenytoin has been used safely and effectively. The arterial blood gas levels, pH, and electrolyte concentrations should be monitored so that metabolic acidosis or hypokalemia can be identified that would further aggravate the arrhythmias. Electrical pacing may be required if the antiarrhythmic drugs fail. Hyperpyrexia is treated by cooling. Seizures may be managed by intravenous doses of diazepam. 

PROCAINAMIDE ANTI HYPERTENSIVES AND HEART FAILURE DRUGS-ACE INHIBITORS Possible T risk of leukopenia Uncertain at present Monitor FBC before starting treatment, 2-weekly for 3 months after initiation of therapy, then periodically thereafter... 

These interaetions are not elearly established, and the reaction appears to he rare and unpredictable. All that can he constructively said is that patients taking both drugs should he very closely monitored for any signs of hypersensitivity (e.g. skin reactions) or low white cell count (sore throat, fever), especially if they have renal impairment. The UK manufacturer of captopril recommends that diffeiential white hlood cell counts should be performed before adding allopurinol, then every 2 weeks during the first 3 months of treatment, and periodically thereafter. Similar caution and advice is given by the UK manufacturers of several other ACE inhibitors. For other possible interactions with ACE inhihitors that might result in an increased risk of leucopenia see also ACE inhihitors + Azathioprine , p.l8 and ACE inhibitors + Procainamide , p.33. 

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