Stockholm, Sweden, when a sunny day or a lot of sun, doctors seem to prescribe drugs with a dose higher than during the rainy season. The new study found that while a lot of summer sun, the drug becomes less effective.Swedish scientists have shown that extra vitamin D is produced by the body in the months in the summer, to accelerate the body's ability to break down drugs. This makes the job becomes less effective drug.
The findings are based on a study of 6,000 people shows that doctors should reduce the dosage of some drugs in the months of winter darkness and increasing the dose on a sunny summer and a lot of sunlight.
Researchers say the findings could have implications for half of all prescription drugs, but they also warn patients not to change the dose without consulting your doctor.
In this study, researchers studied 70 000 blood samples from organ transplant patients who drank one of three drugs that suppress the immune system functioning in Stockholm, Sweden, more than 10 years.
Samples taken during the winter in Stockholm that only a few bright and even almost no sunlight, compared with samples taken on the long summer.
According to findings published in the journal Drug Metabolism and Disposition, drug concentrations vary throughout the year in a manner that closely reflected the changes in levels of vitamin D, namely the nutrients produced by the body in response to sunlight.
The highest vitamin D levels achieved in the months of summer, which causes the effectiveness of 2 types of immune system-suppressing drugs to 7 to 17 percent lower.
Researchers believe that vitamin D may increase the amount of chemicals released by the liver is involved in deciphering the drug.
"As much exposure to sunlight, the body release a chemical or an enzyme known as CYP3A4, are involved in the metabolism of about half of all drug types. And we watched some of the drugs can be affected by sunlight," explained Dr. Erik Eliasson, who conducted research at the Karolinska Institute, as reported by Dailymail, Friday (11/03/2011).
According to Dr Eliasson, is still too early to provide concrete advice for doctors or patients. But it is important to remind patients not to change the dose of the medicine without talking to the doctor.
"Further studies will be needed to confirm these results, but CYP3A4 is considered the most important enzyme in the turnover of drugs in the body and the results may have significance for many drugs," continued Dr Eliasson.
Dr Eliasson also said that researchers are investigating whether sunlight accelerate the workings of the body to break down warfarin, blood-thinning drug. This is because only a few small changes in concentrations of warfarin, it can trigger life-threatening bleeding.
source: http://health.detik.com/read/2011/03/11/102205/1589307/763/efek-obat-jadi-kurang-efektif-jika-banyak-sinar-matahari