Page 122 - pharma 1 theoretical updated MNU_Neat

Clinical pharmacy 2024/2025 Level 3 Pharm D Pharmacology 1 (PO 502)

D-DIs &
 Phosphodiesterase V inhibitors [sildenafil, tadalafil, vardenafil]
Contraindicat ➔potentiate the action of the nitrates.

ion  combination is contraindicated to exclude hypotension

Rapidly. Occur ➔blood vessels become desensitized to vasodilation.

❖ overcome by ➔ providing a daily “nitrate-free interval” to

restore sensitivity to the drug.
❖ Interval ➔ 10 to 12 hours (usually at night, because demand on

Tolerance the heart is decreased at that time.
 Nitroglycerin patches ➔are worn for 12 hours, and then removed
for 12 hours.
 However, variant angina worsens early in the morning, perhaps

due to circadian catecholamine surges ➔so, the nitrate-free
interval in these patients should occur in the late afternoon.

Notes

 Short acting preparations sublingual Nitroglycerin (used in acute attacks)
 Long-acting oral preparations (used in between the attacks)

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