When I told my family doctor that I was taking just half the dose of the medication he prescribed for my anxiety disorder, he didn’t like it, telling me that at such a low dose, it would render the drug ineffective.
“It was the only placebo effect that makes you believe it was working… It actually didn’t touch you at all,” he told me.
But I knew that at that dosage, the drug has helped lower my stress level, allowing me to feel relaxed while showing minimum side effects. But I didn’t come to this finding without price. When I tried the prescribe dosage by following my doc’s order, terrible symptoms of overdose -- from racing heartbeat to dizziness to fatigue – had taken a heavy toll on my predisposed vulnerability to anxiety and stress, leading to my repeated attempts to quit the drug altogether.
But my Caucasian doctors’ words only made me more frustrated and confused. “Why did the dose that won’t work on others made me respond to it?” Do I respond to all drugs in a similar way? Would I experience drug overdose if I follow my doctors’ orders for other drugs he would prescribe in future?”
The fact is that individual human beings react to drugs differently and that a set of specific genes shape a person’s response to medications. While somebody who takes 10 medicine a day, throws them back with a glass of wine and just be okay, others broke out in a full-body rash in response to antibiotic to stave off infection.
A poor metabolizer of certain drugs carries gene variants that hamper their ability to covert the drugs to its active form, while a rapid metabolizer would break down the drug too quickly and get it eliminated from their system at a faster speed. As such, a poor metallizer may face increased intoxication even life-threatening risks for taking a dosage that would render it less effective or even useless at all to a rapid metabolizer.
Ethnicity plays a significant role in the process of drug metabolism. African descendants usually require higher drug doses than Asians or Caucasians because they, as the world’s oldest ancestral group, carry more diverse liver enzymes that allow them to break down drugs and eliminate them more quickly. Asians, meanwhile, tend to require lower drug doses than do Caucasians to control certain conditions, such as high cholesterol, blood clotting and hypertension, due to their inferior metabolizer status.
在对病人吸收药物能力一无所知情况下盲目开处方会导致不可设想的后果。有一大部分夏威夷居民携带某种基因变种，使他们服用中风后防止血液凝结的药物后出现危及生命的药物中毒。2014年， 夏威夷州向制药商Bristol-Myers Squibb and Sanofi-Aventis发起法律诉讼，指控其大力推广一种令这一太平洋岛屿的居民服用后出现高度死亡率的药物。
Prescribing drugs while ignorant of patients’ metabolizer status could cause deadly consequences. A significant portion of Hawaiian population carry gene variants that could render them dangerous to Plavix, a drug used to prevent blood clots after a stoke. In 2014, the State of Hawaii filed a suit against Bristol-Myers Squibb and Sanofi-Aventis for allegedly marketing a drug that left many Pacific Islanders dying at a higher rate wile taking it.
But people of the same ethnicity can have very different genetic drug profile. The good news is that a generic test analysing whether a medication is safe and effective for each individual will soon available on the Canadian pharmaceutical market, allowing doctors to predict which drug a patient will adequately metabolize, particularly for patients suffering depression and anxiety like myself. Some doctors believe that Ontario government may cover pharmacogenetic testing within two years.
But the testing is currently only available to the privileged few – such as company executives and the well heeled individuals. A doctor who, knowing his genetic drug profile took half the regular dose of a blood thinner during a recent surgery, said “It makes me feel guilty that this is not universally available.”
And it has made me jealous. Had I armed with this powerful genetic test results -- I would have been given the right dose of anti-depression at the outset -- without going through the side effects and the additional stress.
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