Ask Dr. H: A melatonin dose can help you sleep, but easy does it
Question: How does a melatonin supplement work? I know that it's helpful for sleep, but it's a hormone and not a sedative like Ambien or Lunesta.
Question:
How does a melatonin supplement work? I know that it's helpful for sleep, but it's a hormone and not a sedative like Ambien or Lunesta.
Answer: You're exactly right. Melatonin is not a sedative, but a hormone secreted by the pineal gland in the brain that's involved in regulating the body's master clock and helping the body distinguish when we should be awake and when we should be asleep (a biological time cue). That's why, in small doses, melatonin supplements have been used to help people adapt to changes in sleep-wake cycles, like from jet travel across time zones or from shift work.
When you take an over-the-counter melatonin supplement of 2-6mg 30 to 90 minutes before bedtime, it advances the internal time clock because of a brief spike in the blood melatonin level and makes your body think it's later than it really is. For some folks, that will help with initial insomnia (difficulty falling asleep). Unfortunately, melatonin has not been shown to be very effective for chronic sleep disorders.
Since a low light level is a stimulus for the secretion of melatonin, be sure to keep your room dark. An important piece of information about the use of melatonin is that more is not necessarily better. Too large a dose of supplemental melatonin (more than 6mg) will spill over onto the wrong side of the melatonin-regulated sleep-wake cycle and actually cause a melatonin-induced insomnia.
Why didn't pneumonia shot work?
Q:
I'm 78 years old. I received the pneumonia vaccine in 2004. At that time, my doctor said that the vaccination lasts 10 years. Can you explain why I was hospitalized this past summer with pneumonia?
A: Many folks think that their pneumonia shot will keep them from getting pneumonia, and that's not quite true. The pneumonia shot protects only against pneumococcal (streptococcal) pneumonia, the most common cause of bacterial pneumonia. And even that's only 60 to 70 percent effective at best. Other bacteria like H. influenza, staphylococcus, mycoplasma, chlamydia and neisseria also cause bacterial pneumonia. Viruses like influenza, respiratory syncytial virus (RSV), adenovirus, and parainfluenza can cause pneumonia that's viral. A flu shot will only protect against viral pneumonia if the cause of the infection is influenza.
As far as how long the pneumonia (pneumococcal) vaccine lasts, it can provide years of protection to someone younger than 65 with a healthy immune system. It's recommended that a second shot be given once a healthy person reaches 65. Folks who have any form of chronic illness should be revaccinated every five years.