Glycerol Trinitrate Patch

(GTN Patch)







-  Short acting nitrate which causes venodilation & arterial vasodilation



-  Tan colored patches

-  Oval 25mg patch = 5mg/24hrs

-  Oblong 50mg = 10mg/24hrs

-  Apply to dry, hairless, clean skin

-  Leave on for 12hrs

-  Apply next patch to different area



-  Systolic BP <90

-  HR <50



-  Angina prevention

-  Heart failure --> CCF/APO

-  AMI

-  Anal fissures

-  Often used as a quick fix for HTN

-  Other

-  May be used close to IV canula site to keep vein open

-  Mx of enthesopathies with 1/4 25mg patch kept on 24hrs (lateral epicondylitis)


Side Effects

-  Headaches: sudden, intense

-  Dizziness, weakness, flushing

-  Postral hypotension, syncope

-  Bradycardia (uncommon), tachycardia

-  Tolerance: loss of symptomatic & haemodynamic effects

-  Reduced by 8-12hr/day wo patch

-  Remove before defibrillation: risk of explosion

-  Do not prescribe w Sildenafil (Viagra), Tadalafil (Cialis) or Verdenafil (Levitra): may produce severe hypotension