Pronestyl

Generic Name: Procainamide hydrochloride
Product Name: Pronestyl

Indication

Pronestyl capsules are used in patients with life threatening abnormal heart rhythms. As an injection, Pronestyl is used to reverse severe and life threatening abnormal heart rhythms in hospital under continuous monitoring.

Action

Pronestyl (procainamide) reduces the excitability of the heart muscle to electrical activity, meaning the heart is less likely to start or continue with abnormal heart rhythms

Pronestyle has a half life of 2.5-5 hours, its main by-product has a half life of 6-8 hours. The drug is excreted by the kidneys.

Dose advice

The dose should be titrated to maintain therapeutic effect as judged by clinical effect, and is dependent on the patientâ??s age, weight and general condition, renal elimination, hepatic acetylation rate and cardiac status.
Oral procainamide is preferable for treating non life-threatening arrhythmias, and for long term maintenance therapy after initiating treatment with parenteral therapy.
Parenteral therapy is indicated for life-threatening arrhythmias, and those patients in whom oral therapy is not appropriate (e.g. patients with nausea or vomiting, patients who are nil by mouth, or patients who might have unreliable gut absorption). Intravenous therapy allows rapid control of serious arrhythmias, though it should only be carried out in the setting of hospitals or emergency facilities with access to close observation including blood pressure and ECG monitoring to avoid a possible hypotensive reaction. Intravenous therapy should be ceased in the presence of persistent conduction disturbances (e.g. excessive widening of QRS complex or prolongation of the PR interval) or hypotension (e.g. a fall in blood pressure of more than 15 mmHg)
Intramuscular administration is less likely to produce temporary high plasma levels than intravenous therapy, however therapeutic plasma levels take longer to achieve.
When switching from parenteral Pronestyl to oral, 3-4 hours (i.e. one half life for renal elimination) should elapse between the last parenteral dose and the first oral dose.
Parenteral drug products should be examined visually for particulate matter and discolouration prior to administration.
Impaired renal or hepatic function: Renal or hepatic impairment both prolong Pronestyl elimination, and doses should be reduced or dosing intervals increased in order to give adequate blood levels and reduce the incidence of dose related adverse effects.
Elderly patients/Cardiac insufficiency: Lower doses or longer dosing intervals should be used in older patients (to account for age related changes in renal function), and patients with cardiac insufficiency, to give therapeutic blood levels and reduce the incidence of dose related adverse effects.

Schedule

S4

Common side effects

Side effects are less common with Pronestyl capsules than with injections.
-Hypotension (low blood pressure), serious cardiac rhythm disturbances (including heart block).
-A lupus erythematosus like syndrome is fairly common after prolonged therapy, (the clinical picture includes arthralgia, pleural or abdominal pain, and sometimes arthritis, pleural effusions, pericarditis, fevers, chills, myalgia, and possibly haematological or skin lesions. It may be preceded by a rising titre of serum ANAs). If discontinuation of procainamide does not reverse symptoms, corticosteroid treatment may be effective.

Uncommon side effects

-Nausea, vomiting, anorexia, abdominal pain, diarrhoea, bitter taste, acute hepatomegaly, increased serum aminotransferase.
-Angioneurotic oedema, urticaria, maculopapular rash, flushing and pruritus.
-Muscular weakness has been reported in patients with supra therapeutic blood concentrations of Pronestyl.
-Dizziness, weakness, mental depression and psychosis with hallucinations have been observed.

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For further information talk to your doctor.