ANTI-ARRYTHMIC AGENTS

Question 1

What are anti-arrhythmic agents?

Answer 1

These are drugs that are used to suppress abnormal rhythm of the heart I.e cardiac arrhythmias.

Question 2

What is cardiac arrhythmia

Answer 2

They alter the pattern of contraction or mark an increase or decrease in heart rate reducing the ability of the heart to pump blood I.e atrial flutter,atrial fibrillation(irregular heart rate leading to poor blood flow) and ventricular fibrillation.

Question 3

Give the pharmacology of Amiodarone Hcl

Answer 3

Trade name: Procor
Class: Anti-arrhythmic agent
Mode of action: It acts directly on myocardial cells, blocking potassium channels and prolonging action potential duration and the refractory period.
Therapeutic uses:should be reserved for life threatening ventricular arrhythmia that doesn’t respond to other therapies.
Contraindications:
-sinus bradycardia
-Av block
- Thyroid dysfunction 
Side effects: 
-Bradycardia
-CHF
-Tremor
-Visual disturbance 
-Hemolytic/aplastic anaemia
-Hepatoxicity
Doses: Tablet form-200mg daily.
             IV infusion-5mg/kg body weight over 20                -120 minutes.

Question 4

Give the pharmacology of lidocaine hydrochloride.

Answer 4

Trade name: Sylocaine
Class: Anti-arrhythmic agent
Moa: Suppresses automacity of ventricular cells,decreasing diastolic depolarization and increasing ventricular fibrillation threshold.
Clinical uses: Acute ventricular arrhythmia
Myorcardial infarction
Contraindications: Hypersensitivity
Heart block
Side effects: Dyspnea
Dizziness
Hypotension
Dosage: Available in ampoule of conc of 1% (100mg),IV Bolu’s of 50 & 100mg at the rate of 25-50mg per minute .
Nursing considerations:
- Don’t add lidocaine to blood transfusion assembly
- Use 5% dextrose solution to prepare drug and its state for 24 hours
- Assess for history of hypersensitivity
- Obtain blood pressure,pulse rate and respiration rate to use as baseline data
- Drug should be given in a monitored environment
-If adverse reaction occur,discontinue infusion and prepare for an emergency management.

Question 5

Give the pharmacology of phenytoin

Answer 5

Trade name :Dilantin
Class: Anti-arrhythmic and anti-convulsants
Moa: It acts in the mirror cortex in the brain to reduce the spread of electrical discharge for rapidly firing epileptic fossa in this area in the brain.
Clinical uses: Chronic epilepsy,premature ventricular contraction,tachycardia.
Contraindications: Hypersensitivity
Side effects: Drowsiness,measles like rash,gingival hyperplasia,hirsutism and hypoglycemia.
Doses: For arrhythmia- 200-400mg daily (tablet)
IV - 100mg up to 1g
Nursing consideration:
-IV phenytoin may form precipitate so flush tubing by saline and not dextrose before and after administration
- Asses for hypersensitivity
- Advice a pregnant woman to not breastfeed if she is still on the drug after delivery.
- During IV infusion monitor BP for signs of hypotension
- Give food to the patient to avoid GI upset
- Of the patient is diabetic,monitor for signs of hypoglycemia
-Report any case of excessive hair growth

Question 6

Give the pharmacology of procainamide

Answer 6

Trade name:procam
Class: Anti-arrhythmic agent
Moa: Suppressing the conduction of cardiac impulses and produce a direct cardiac effect to prolong the refractive period of the heart.
Clinical uses: Ventricular tachycardia,atrial fibrillation,digitalis intoxication.
Contraindications: Hypersensitivity and Av heart block
Side effects: Hypotension,abdominal pain,bitter taste.
Dosage :Injection:100mg/ml and 500mg/ml
Adult dose for arrhythmias;
IM- 0.5mg to 1g every 4 to 8 hours.
IV- 100 to 200mg per dose or 15-18mg/kg body weight infused slowly over 25 to 30 mins and you may repeat as needed and not to exceed 1g.
In renal impairment;
Reduce the loading dose to 12 mg per kg body weight .
Reduce the infusion to one third In moderate renal /cardiac impairment and two third in severe renal/cardiac impairment.
In hepatic impairment;
Reduce the dose by 50%