What causes opioid addiction, and why is it so tough to combat? - Mike Davis

譯者: Lilian Chiu 審譯者: Helen Chang

More than 3,000 years ago, a flower began to appear in remedies

三千多年前，

有一種花開始出現在

古埃及醫學文獻記載的療法當中。

in Ancient Egyptian medical texts.

Across the Mediterranean, the ancient Minoans

在地中海地區各地，古米諾斯人

likely found ways to use the same plant for its high.

很可能找到一些方法 來使用同一種花帶來的快感。

Both ancient civilizations were on to something—

這兩個古文明都找到了 一樣很重要的東西——

opium, an extract of the poppy in question,

從前面提到的罌粟花 所粹取出來的鴉片，

can both induce pleasure and reduce pain.

能夠引發愉悅感和減輕痛苦。

Though opium has remained in use ever since,

雖然從那之後就一直 有人在使用鴉片，

it wasn’t until the 19th century that one of its chemical compounds,

要到十九世紀時， 它的一種化合物，

morphine, was identified and isolated for medical use.

嗎啡，才被發現 並獨立出來做為醫療用途。

Morphine, codeine, and other substances made directly from the poppy

嗎啡、可待因，及其他直接 由罌粟花製成的物質

are called opiates.

稱為鴉片劑。

In the 20th century, drug companies created a slew of synthetic substances

二十世紀時，藥廠 創造出許多合成物質，

similar to these opiates,

和這些鴉片劑很類似，

including heroin, hydrocodone, oxycodone, and fentanyl.

包括海洛英、氫可酮、 氧可酮、芬太奴。

Whether synthetic or derived from opium,

不論是合成的或從鴉片衍生出來，

these compounds are collectively known as opioids.

這些化合物統稱為鴉片類藥物。

Synthetic or natural, legal or illicit, opioid drugs

不論是合成的或天然的、 合法的或非法的，

鴉片類藥物都是非常有效的止痛劑，

are very effective painkillers, but they are also highly addictive.

但也極容易上癮。

In the 1980s and 90s,

在 1980、90 年代，

pharmaceutical companies began to market opioid painkillers aggressively,

藥廠開始積極推銷鴉片類止痛劑，

actively downplaying their addictive potential

還積極淡化它們會成癮的可能性，

to both the medical community and the public.

不論對醫界或大眾皆是如此。

The number of opioid painkillers prescriptions skyrocketed,

鴉片類止痛劑的處方數量大增，

and so did cases of opioid addiction, beginning a crisis that continues today.

鴉片類藥物成癮的案例數亦大增，

從此這個危機就一直持續至今。

To understand why opioids are so addictive,

若要了解為什麼 鴉片類藥物如此容易上癮，

it helps to trace how these drugs affect the human body from the first dose,

可以先去追蹤這些藥物 會如何影響人體，

從第一劑開始，經過重覆使用，

through repeated use, to what happens when long-term use stops.

一直到長期使用停止 之後會發生什麼事。

Each of these drugs has slightly different chemistry,

這類藥物的化學性質各有些微不同，

but all act on the body’s opioid system by binding to opioid receptors in the brain.

但對人體鴉片系統的影響方式

都是和大腦中的鴉片受體結合。

The body’s endorphins temper pain signals by binding to these receptors,

身體的腦內啡會結合這些受體， 用這種方式來減少痛苦訊號，

and opioid drugs bind much more strongly, for longer.

而鴉片類藥物的結合力 更強、更持久。

So opioid drugs can manage much more severe pain than endorphins can.

所以鴉片類藥物比腦內啡 更能處理強烈的痛苦。

Opioid receptors also influence everything from mood to normal bodily functions.

鴉片受體也會造成許多影響， 影響範圍從心情到正常身體功能。

With these functions, too, opioids’ binding strength and durability

鴉片類藥物也有這些功能， 且更強、更持久，

mean their effects are more pronounced and widespread

這就表示它們的效果會比

人體本身的傳訊分子 還要更深、更廣。

than those of the body’s natural signaling molecules.

When a drug binds to opioid receptors, it triggers the release of dopamine,

當藥物和鴉片受體結合時， 就會觸發多巴胺的釋放，

which is linked to feelings of pleasure and may be responsible

多巴胺和愉悅感有關，

可能是鴉片類藥物帶來快感的成因。

for the sense of euphoria that characterizes an opioid high.

At the same time, opioids suppress the release of noradrenaline,

同時，鴉片類藥物會抑制 正腎上腺素的釋放，

which influences wakefulness, breathing, digestion, and blood pressure.

正腎上腺素會影響到失眠、 呼吸、消化，和血壓。

A therapeutic dose decreases noradrenaline enough to cause side effects

治療用的劑量能夠 將正腎上腺素減少到

足以產生副作用 （如便秘）的程度，

like constipation.

At higher doses opioids can decrease heart and breathing rates to dangerous levels,

更高劑量的鴉片類藥物能將心跳

和呼吸頻率降低到危險的程度，

causing loss of consciousness and even death.

導致失去意識，甚至死亡。

Over time, the body starts to develop a tolerance for opioids.

隨著時間，身體開始發展出 對鴉片類藥物的耐受性。

It may decrease its number of opioid receptors,

身體可能會減少鴉片受體的數目，

or the receptors may become less responsive.

或者受體的反應會降低。

To experience the same release of dopamine and resulting mood effects as before,

若要感受到和以往同等的多巴胺 釋放量以及它造成的心情效應，

people have to take larger and larger doses—

攝取的劑量就必須越來越高——

a cycle that leads to physical dependence and addiction.

這個循環會導致 身體的依賴性以及上癮。

As people take more opioids to compensate for tolerance,

若攝取更高的劑量來彌補耐受性，

noradrenaline levels become lower and lower,

正腎上腺素的量就會越來越低，

to a point that could impact basic bodily functions.

低到可能會影響基本的身體功能。

The body compensates by increasing its number of noradrenaline receptors

身體的代償方式就是增加 正腎上腺素受體的數量，

so it can detect much smaller amounts of noradrenaline.

這樣便能偵測到 更少量的正腎上腺素。

This increased sensitivity to noradrenaline

這麼做會增加 對正腎上腺素的敏感度，

allows the body to continue functioning normally—

讓身體能持續正常運作——

in fact, it becomes dependent on opioids to maintain the new balance.

事實上，身體會變成 要依賴鴉片類藥物

才能維持這種新的平衡。

When someone who is physically dependent on opioids stops taking them abruptly,

如果一個人的身體 已經在依賴鴉片類藥物，

卻突然停止這類藥物，

that balance is disrupted.

這種平衡就會中斷。

Noradrenaline levels can increase within a day of ceasing opioid use.

正腎上腺素的量會在中止使用 鴉片類藥物的一天內就增加。

But the body takes much longer to get rid of

但身體要更長的時間才能擺脫

all the extra noradrenaline receptors it made.

它額外製造的正腎上腺素受體。

That means there’s a period of time

那就表示，有一段時間，

when the body is too sensitive to noradrenaline.

身體會對正腎上腺素太過敏感。

This oversensitivity causes withdrawal symptoms,

這種況度敏感會造成戒斷症狀，

including muscle aches, stomach pains, fever, and vomiting.

包括肌肉疼痛、胃痛、發燒、嘔吐。

Though temporary, opioid withdrawal can be incredibly debilitating.

雖然是鴉片類藥物戒斷暫時性的， 也有可能會讓人變得非常虛弱。

In serious cases, someone in withdrawal can be violently ill

情況嚴重時，戒斷的人可能會

for days or even weeks.

有數日甚至數週都病得很重。

People who are addicted to opioids aren't necessarily using the drugs

鴉片類藥物成癮的人此時 就不見得只是為了快感而用藥，

to get high anymore, but rather to avoid being sick.

也是為了避免生病。

Many risk losing wages or even jobs while in withdrawal,

許多人在戒斷時，要冒著 失去薪水甚至工作的風險，

or may not have anyone to take care of them during withdrawal.

或者可能在戒斷時期 沒有人能去照顧他們。

If someone goes back to using opioids later,

如果之後又再回頭用鴉片類藥物，

they can be at particularly high risk for overdose,

用藥過量的風險就會特別高，

because what would have been a standard dose while their tolerance was high,

因為當他們的耐受度很高時 所使用的標準劑量

can now be lethal.

現在卻可能是致命的劑量。

Since 1980, accidental deaths from opioid overdose

1980 年起，在美國 因鴉片類藥物過量

have grown exponentially in the United States,

致死的人數高速成長，

and opioid addictions have also exploded around the world.

鴉片類藥物成癮也在世界各地爆發。

While opioid painkiller prescriptions are becoming more closely regulated,

雖然對鴉片類止痛劑 處方的規制變得更嚴謹，

cases of overdose and addiction are still increasing,

用藥過量和成癮的案例數 仍然不斷增加，

especially among younger people.

特別是較年輕的人。

Many of the early cases of addiction were middle-aged people

早期，許多成癮的案例是中年人，

who became addicted to painkillers they had been prescribed,

他們上癮是因為處方中的止痛劑，

or received from friends and family members with prescriptions.

或取自有處方的親朋好友的止痛劑。

Today, young people are often introduced to prescription opioid drugs in those ways

現今，年輕人通常也經由這些方式 初次接觸到處方鴉片類藥物，

but move on to heroin or illicit synthetic opioids that are cheaper

但接著就開始改用海洛英 或非法的合成鴉片類藥物，

and easier to come by.

比較便宜也比較容易取得。

Beyond tighter regulation of opioid painkillers,

除了對鴉片類止痛劑 訂更嚴格的規定之外，

what can we do to reverse the growing rates of addiction and overdose?

我們還能怎樣反轉 不斷增長的上癮和過量用藥？

A drug called naloxone is currently our best defense against overdose.

目前對抗用藥過量的最佳防禦 是一種叫做納洛酮的藥物。

Naloxone binds to opioid receptors but doesn’t activate them.

納洛酮會和鴉片受體結合， 但不會啟動它們。

It blocks other opioids from binding to the receptors,

納洛酮會阻擋其他 鴉片類藥物和受體結合，

and even knocks them off the receptors to reverse an overdose.

甚至將它們踼出受體， 反轉用藥過量。

Opioid addiction is rarely a stand-alone illness;

鴉片類藥物成癮 通常不是獨立的疾病；

frequently, people with opioid dependence are also struggling

依賴鴉片類藥物的人 常有心理健康疾病的問題。

with a mental health condition.

There are both inpatient and outpatient programs that combine

對針對住院病人 及門診病人提供的計畫，

medication, health services, and psychotherapy.

結合了藥物治療、健康服務， 以及精神療法。

But many of these programs are very expensive,

但這類專案計畫通常很昂貴，

and the more affordable options can have long waiting lists.

比較負擔得起的選擇， 則是等候名單一長串。

They also often require complete detoxification from opioids

這類計畫通常也要求 參與者要先完成

鴉片類藥物的解毒， 才能開始治療。

before beginning treatment.

Both the withdrawal period and the common months-long stay in a facility

在戒斷期及在機構中待上 數個月的期間有可能會

can be impossible for people who risk losing jobs and housing in that timeframe.

失去工作和住所的人， 不太可能冒這個險。

Opioid maintenance programs aim to address some of these obstacles

鴉片類藥物維持計畫的目標 就是在處理一些這種障礙，

and eliminate opioid abuse using a combination

並消除鴉片類藥物濫用，

做法是結合藥物治療和行為療法。

of medication and behavior therapy.

These programs avoid withdrawal symptoms with drugs

這些計畫避免戒斷症狀的方式

是使用能與鴉片受體結合的藥物，

that bind to opioid receptors but don’t have the psychoactive effects

而這些藥物並不像止痛劑、海洛英，

of painkillers, heroin, and other commonly abused opioids.

及其他常被濫用的鴉片類藥物 會造成心理影響。

Methadone and buprenorphine

美沙酮和丁丙諾啡

are the primary opioid maintenance drugs available today,

是現今主要用來處理 鴉片類藥物成癮的維持藥物，

but doctors need a special waiver to prescribe them—

但醫生要有特殊的棄權條款 才能開這種處方——

even though no specific training or certification

不過，開鴉片類止痛劑的處方

is required to prescribe opioid painkillers.

並不需要特殊訓練或認證。

Buprenorphine can be so scarce

丁丙諾啡很稀少，

that there’s even a growing black market for it.

其黑市甚至不斷在成長。

There’s still a long way to go with combating opioid addiction,

在對抗鴉片類藥物成癮方面， 還有很長的路要走，

but there are great resources for making sense of the treatment options.

但有很棒的資源 可以弄懂治療的選擇。

If you or someone you know is struggling with opioid use in the United States,

如果你或是你認識的人在美國 面臨鴉片類藥物使用的困難，

the Department of Health and Human Services

衛生及公共服務部

operates a helpline: 800-662-4357

提供諮詢服務的電話： 800-662-4357

and a database of more than 14,000 substance abuse facilities in the US:

及超過一萬四千多筆 美國藥物濫用機構資訊的資料庫：

www.hhs.gov/opioids

www.hhs.gov/opioids。