Hyperpolarization-Activated Cyclic Nucleotide-Gated Channel Blockers

Question 1

HCN Blockers-

Answer 1

A NEW class of drugs was approved for treatment of patients with HF

Question 2

HCN Blockers

MOA-

Answer 2

Blocks the HCNs and slows the hearts pacemaker, the sinus node in the repolarizing phase of the action potential

Question 3

HCN Blockers

Indications-

Answer 3

• For chronic HF

- Slows the heart and decreases the workload

Question 4

HCN Blockers

Name-

Answer 4

Ivabradine (P)

Question 5

HCN Blockers

Contraindications-

Answer 5

• Allergy
• Active, decompensated HF
• Hypotension
• Sick sinus syndrome of AV block
• Resting HR under 60
• Pt dependent on pacemaker
• Sever hepatic impairment

Question 6

HCN Blockers

Caution-

Answer 6

• Afib

- Moderate heart block

Question 7

HCN Blockers

Adverse Effects-

Answer 7

• Bradycardia
• Hypertension
• Afib
• Luminous phenomena (sudden change in brightness, colored bright lights, image decompensation, multiple images)

Question 8

HCN Blockers

Drug-Drug

Answer 8

• CYP3A4 inhibitors or inducers

- Negative chronotropic drugs (=slower HR, can cause severe bradycardia- ex: digoxin and HCN= NO!)

Question 9

HCN Blockers

Implenmentation-

Answer 9

• Monitor HR and BP frequently
• Monitor input/output
• Provide safety measures if visual disturbances occur
• Provide patient teaching