Chronotherapy is the treatment of illness or disorders by administering drugs at times that are in harmony with the body's circadian rhythms. Circadian rhythms are 24-hour cycles that regulate essential functions and processes like sleep, temperature, and organ function. There is evidence that timing medication doses to match circadian rhythms can increase benefits and reduce side effects. Specifically for hypertension, the normal daily dip in blood pressure at night is disrupted, increasing cardiovascular risk. Studies show administering blood pressure medications at bedtime helps control blood pressure and reduces cardiovascular events and organ damage compared to other dosing times.

1. WHAT IS CHRONOTHERAPY
The treatment of an illnessor disorder by administeringa drugata time of day believed to be in harmony with the
body’s natural rhythym called CIRCADIAN RYTHM”.Chronotherapy with medications involves thetailored timingof
doses to match the body’s rhythms and behavioral patterns in order to increasebeneficial effects and/or minimize
any adverse medication effects across theday and night. Given the emerging knowledge that circadian rhythmicity
exists in every cell and all organ system, there is increasinginterestin the possiblebenefits of chronotherapy for
many diseases
CIRCADIANRYTHYM
Circadian rhythms are24 hours cycles thatare partof the body’s internal clock,runningin the background to carry
out essential functions and processes.Differentexamples of circadian rhythms aresleep wake cycle, temperature
cycle, rest activity and fasting-feedingcycles,gastric ph regulation , organ blood flow , renal function and liver
enzyme activity.These cyclic rhythms aremaintained by body’s Neuro-hormonal system.
Circadian Rhythm of Blood PressureThereis a well documented 24 hour pattern of blood
pressurewith peak in early morning and fall duringnight.The autonomic nervous system is the prime suspectin
mediating the circadian variation in blood pressure.In hypertension this normal variation in morningand nightBP
is disturbed.Nocturnal dippingof BP is partof this normal cycleand its absence (non dippi ng) is more frequent in
hypertensive patients and is associated with more severe end organ damage and increased risk of CV events.
CARDIOVASCULAREFFECTS
Cortisol exhibits a 24h circadian rhythmthat effects the brain,autonomic nervous system , heart and the
vasculaturethatprepares the CVS for optimal functioning.Morningsurgeof cortisol levels areappears to be an
objective biological marker of the stress response that can be related do adversecardiac events likemyocardial
infarction ,ventricular fibrillation in early morning.
CONCLUSION
From different studies and trials itcan beconcluded that timingof blood pressuremedication has great impactto
avoid CV morbidity and mortality.Not only combinations of drugs and/or an increasein medication dosageto
control blood pressureis necessary butbed time administration 0f medications havegreat impacton blood
pressurecontrol too