What are the main classes of drugs which act on the heart?
Two major groups used clinically for treatment of cardiac
conditions are:
ACTION
ANTIARRHYTHMIC
Antiarrhythmic
drugs
:
Cardiac depressant, slow excitability of
heart correct heart rate and rhythm.
Ex: Quinidine, Pronestyl (procainamide)
Route
and Dosage:
Quinidine:
P.o. Griii q 4 h
Pronestil:P.O. I.V. I_M. 250mg
SIDE
EFFECTS
:
Quinidine
Pronestyl: Central nervous
system,G.I. slow pulse
pranestyl Central nervous system,G.I. slow pulse,
except cinchonism.
Nursinq
Implications:
Quinidine:
check apical pulse before giving. withhold, chart and
circle duty time and notify doctor if marked changes
in rate,
quality or rhythm of heat beat.
RATIONALE
:
An anti arrythmic drug such as quinidine may dislodge
thrombi by promoting vigorous atrial contraction. The thrombus or thrombi may
enter the circulation and cause: pulmonary, cerebral, or multiple embolism. To
reduce the likelihood of embolic phenomena, an anticoagulant such as. heparin
may be administered before and during quinidine therapy to patients with a long
history of atrial fibrillation. In addition, it can cause thrombocytopenia as a
result of platelet agglutination and lysing. NURSES should carefully observe
patients on quinidine therapy for bleeding tendencies such as petechiae,
ecchymosis or purpura, epistaxis, etc.
NURSING
IMPLICATIONS PRONESTYLE :
Check apical pulse for 1 minute. If marked change in rate, report to the
Doctor. If given IV, the nurse should monitor the patient's blood pressure and
EKG for the same changes as quinidine.
Watch
for: hypotension and systemic lupoid reaction.
Cardiotonic Drug :
A) Digitalis
B) Digoxin, Lanoxin
C) Digitoxin
ACTION
A:
Excitatory or stimulating effect on the heart. Increase the
contraction power of cardiac muscle. Treat heart pump failure
Route a Dosage :P.O. IM O.lgm daily
Side Effects: Nausea, vomiting, diarrhea, bradycardia, collstipation, tinnitus
ACTION
B:
Digoxin; Lanoxin Slows and strengthens heart
Route and Dosage: P.O.I.M. I.V. 0.25 to O.5mg Side Effects: Same as Digitalis
ACTION
C:
Digitqxin : Slows and strengthens heart
Route
and Dosage:
P.O.
0.1 to 1.25
Side
effects: nausea,
vomiting diarrhea, bradycardia,constipation, tinnitus
Nursinq
Implications: Check
Apical pulse before giving.Do not giving medication
if pulse below 60. Potassium
level Circle on drug sheet, notify physician.
RATIONALE
It
should be noted that these two classes of drugs are not mutually
exclusive.Antiarrhythmic drugs can have a cardiotonic effect,and
cardiotonic drugs can correct an abnormal heart rhythm
The
followinq are also antiarrhytluaic druqs
Propranolol
(Enteral) Beta adrenergic
blocking agent;
-DECREASE
RISE OF BLOOD SUGAR
-Prevents
rise of free fatty acids
-Induce
Hypoglycemia
-Potentiate
action of Insulin and oral hypoglycemic drugs
-Lidocaine
(xylocaine)
-Quinidine
like action on the heart
-Used
to control PVC
Effect
with short duration of action 10 to 20 minutes. On
CHS:convulsions,Hypotension,cardiac arrest