THE HEART OF THE MATTER
a special program of the National Emergency Medicine Association (NEMA) 

Week: 529.1 Guest: Dr. Michael Smolensky, Prof. Univ. Of Texas School of Public Health Topic: What is Chronotherapy?- Part One Host: Steve Girard

NEMA: What is chronotherapy? Dr. Michael Smolensky, a professor at the University of Texas School of Public Health joins us today....

Smolensky: Biologically, systems are well organized in time, with biological rhythms of various cycle duration's. The most well-known rhythm is that of the menstrual cycle, which in most women is around 28 to 30 days duration. However, we have other rhythms of the body...another being so very important in medicine is the 24 hour, termed the cirdadian rhythm.

NEMA: How has the knowledge of these biological timescapes turned into the field of chronotherapeutics?

Smolensky: The occurrence of various diseases are not random during the 24 hours, certain cardiovascular clinical events are more common at the start of the activity period, such as acute myocardial infarction, or sudden cardiac death...certain other diseases, such as asthma, are more common during the overnight period... persons who suffer from ulcer disease tend to have more problems with their condition later in the evening. Because we have a very strong, circadian biological time structure, that is we're not the same biochemically or physiologically in the morning versus the evening, our vulnerability to disease is going to be rather different at different times of the day, but in a very predictable manner.

NEMA: How does that knowledge lend itself to the actual treatment of some of the problems you mentioned?

Smolensky: We can use so-called conventionally formulated medications...the time capsule or tablet preparations, at specific times of day, to optimize their efficiency and to make sure that they are safe from side effects, taking into consideration these 24 hour rhythms. However, in certain cases, we need to reconstitute and reformulate our medications with the use of new and modern drug delivery technology, so we can synchronize the plasma concentrations of medications, in direct relationship over the 24 hours, with regard to the need for medication.

NEMA: As it stands right now, what kinds of maladies are best suited for chronotherapeutic treatment?

Smolensky: One, for example, is asthma. There is a specific formulation of a bronchial dilator medication which is marketed, which gives more drug purposely at night than during the day, when asthma is at lower risk to patients. Another application would be for ulcer disease.. There's a circadian rhythm in the secretion of basal acid secretion...tends to be higher at night than during the morning hours, and therefore if we take these so called H-2 receptor blocker medications, these anti-acid medications in the evening, we more effectively treat peptic ulcer disease. Also, the body shows a very distinct 24 hour rhythm in its synthesis of cholesterol and other harmful fatty substances. And this is why its generally recommended that patients take their cholesterol lowering medications generally around dinner time or before bedtime because this is the time when they're most efficient in containing the levels of cholesterol synthesis.

NEMA: Dr. Michael Smolensky will join us again soon to discuss new, specially formulated chronotherapy drugs, and the future of the field. I'm SG.