-The above pharmacologic profile allows for an appreciation of the anti-hypertensive characteristics of amlodipine, how it differs from other CCBs, and why it is a poor choice for inpatient therapy.
-Given the 9 hour lag between agent ingestion and peak concentration (time of peak), meaningful declines in BP will not occur for 6-12 hours.
Consequently, it should be avoided if BP reduction is sought within hours.
-Since the full anti-hypertensive effect will not be realized for more than a week (the amount of time required to achieve a steady state), dose escalation within 1-2 days of initiating therapy will not hasten BP control but only serve to magnify the risk of hypotension in the following weeks.
-In contrast, amlodipine's long half-life and modest variation in plasma concentration (trough-to-peak ratio) ensure a continuous and uniform anti-hypertensive effect throughout the day. Thus, it is an ideal outpatient therapy.
-Given half-lives of 4-5 hours, isradipine and extended release nifedipine act within 4-6 hours and achieve near full effect within days. In the absence of contraindications, these remain my inpatient agents of choice.
: While a medication's effect on BP and its time to onset cannot generally be determined from drug concentrations,
of amlodipine indicate that serum concentrations are a credible indicator of time to anti-hypertensive effect.
-Disclosures: I have no conflicts to declare. My thanks to Sean Kane, Pharm.D. of
for this article.