Procainamide adverse effects

ADMINISTERING PROCAINAMIDE Adverse reactions with procainamide therapy include nausea, loss of appetite, and vomiting. Small meals eaten frequently may be better tolerated than three full meals. Administering the drug with meals may decrease gastrointestinal effects. 

CNS stimulation and hallucinations are rare. The incidence of severe adverse effects in long-term therapy may be lower than those observed with quinidine or procainamide. 

Dicyclomine (Bentyl) [Anrimuscarinic, GI Anrispasmodic/ Anticholinergic] Uses Functional IBS Action Smooth-muscle relaxant Dose Adults. 20 mg PO qid T to 160 mg/d max or 20 mg EM q6h, 80 mg/d - qid then T to 160 mg/d, max 2 wk Feds. Infants >6 mo 5mg/dose tid-qid Children 10 mg/dose tid-qid Caution [B, -] Contra Infants <6 mo, NAG, MyG, severe UC, BOO Disp Caps, tabs, syrup, inj SE Anticholinergic SEs may limit dose Interactions T Anticholinergic effects W/ anticholinergics, antihistamines, amantadine, MAOIs, TCAs, phenothiazides T effects OF atenolol, digoxin X effects H7 antacids X effects OF haloperidol, ketoconazole, levodopa, phenothiazines EMS Avoid procainamide usage, may T adverse effects may T effects of digoxin, monitor... 

Adverse effects With chronic use, procainamide causes a high incidence of side effects, including a reversible lupus erythe-matosus-like syndrome that develops in 25 to 30% of patients. Toxic concentrations of procainamide may cause asystole or induction of ventricular arrhythmias. Central nervious system (CNS) side effects include depression, hallucination and psychosis. With this drug, gastrointestinal intolerance is less frequent than with quinidine. 

There have been a few previous reports of similar adverse effects with procainamide in therapeutic dosages, and in most cases the plasma concentrations of procainamide... 

CIMETIDINE, RANITIDINE ANTIARRHYTHMICS-AMIODARONE, FLECAINIDE, MEXILETINE, PROCAINAMIDE, PROPAFENONE Likely t plasma concentrations of these antiarrhythmics and risk of adverse effects Cimetidine inhibits CYP2D6-mediated metabolism of flecainide, mexiletine, procainamide and propafenone. Ranitidine is a much weaker CYP2D6 inhibitor. Cimetidine is a potent inhibitor of organic cation transport in the kidney, and the elimination of procainamide is impaired Monitor PR and BP at least weekly until stable. Warn patients to report symptoms of hypotension (lightheadedness, dizziness on standing, etc.). Consider alternative acid suppression therapy... 

Hydralazine has been in use since the 1950s and is usually used in combination with other drugs such as diuretics and P-blockers. In a significant number of patients, and typically after 18 months, adverse effects started to appear. These included joint and muscle pain (arthralgia and myalgia), a rash on the face and inflamed blood vessels (vasculitis). The rash on the face made afflicted patients look wolf-like, which gave rise to the name for the syndrome. Lupus erythematosus (Lupus is Latin for wolf). This disease can be caused by other drugs, such as isoniazid very occasionally and procainamide more frequently. It may also have other, unknown, causes and has some similarities with rheumatoid arthritis. 

Apart from the lupus-like syndrome, the adverse effects of acecainide are as common as those of procainamide. The commonest affect the gastrointestinal tract and the central nervous system. Anorexia, nausea, vomiting, diarrhea, and abdominal pain are common, as are insomnia, dizziness, light-headedness, tingling sensations, and blurred vision. Other reported unwanted effects include skin rashes, constipation, and reduced sexual function (2-5). 

The adverse effects of intravenous procainamide (400 mg up to three times infused over 10 minutes) have been reported in 60 adults with atrial flutter or fibrillation in a comparison with ibutihde (2). The adverse effects were headache in 11%, hypotension in 11%, flushing in 3.1%, dizziness in 3.1%, and hypesthesia in 3.1%. The mean fall in systolic blood pressure was about 20 mmHg and occurred at 30-35 minutes after infusion the corresponding fall in diastolic blood pressure was 10 mmHg. However, in seven patients there was severe hypotension, with a fall in diastolic blood pressure of up to 67 mmHg in three cases withdrawal of the infusion was required and these patients were treated with intravenous fluids, dopamine, or both. In the severe cases the hypotension occurred during or immediately after the infusion of procainamide. 

A comparison between procainamide and propafenone in 62 patients, who had undergone coronary artery bypass grafting or valvular surgery within 3 weeks and developed sustained atrial fibrillation, showed that both drugs converted the dysrhythmia to sinus rhythm in up to 76% of cases, but that propafenone did it more quickly (3). Symptomatic arterial hypotension occurred more frequently with procainamide (nine of 33 patients) than with propafenone (two of 29 patients). Other adverse effects of procainamide were nausea (n = 2) and junctional escape rhythm (n = 2). 

The adverse effects of procainamide are predominantly on the heart. It causes reduced myocardial contractility... 

Quinidine has a wide spectmm of adverse effects but causes increased—not decreased—gastrointestinal motility and often results in diarrhea. Procainamide causes lupus quinidine causes thrombocytopenia amiodarone causes thyroid dysfunction. The answer is (A). 

Procainamide causes a reversible syndrome similar to lupus erythematosus Pulmonary fibrosis and thyroid dysfunction are known adverse effects of amiodarone Torsade de pointes arrhythmias are often associated with drugs that prolong action potential duration... 

Disopyramide phosphate is used orally for the treatment of certain ventricular and atrial arrhythmias. Despite its structural dissimilarity to procainamide (Fig. 26.10), its cardiac effects are very similar. Disopyramide is rapidly and completely absorbed from the gastrointestinal tract. Peak plasma level is usually reached within 1 to 3 hours, and a plasma half-life of 5 to 7 hours is common. Approximately half of an oral dose is excreted unchanged in the urine. The remaining drug undergoes hepatic metabolism, principally to the corresponding N-dealkylated form. This metabolite retains approximately half the antiarrhythmic activity of disopyramide and also is subject to renal excretion. Adverse effects of disopyramide frequently are observed. These effects are primarily anticholinergic in nature and include dry mouth, blurred vision, constipation, and urinary retention. 

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