What is an overdose?
An overdose means having too much of a drug (or combination of drugs) for your body to be able to cope with. There are a number of signs and symptoms that show someone has overdosed, and these differ with the type of drug used.
Opioids, benzodiazepines and alcohol are all depressants, which means they slow the central nervous system, including breathing and heart rate. Too much of any one of these substances on their own or in combination can kill or cause permanent brain damage.
Opiates are derived from opium, and there are some drugs such as fentanyl and methadone, that are synthetic drugs manufactured without using opium. Others, like oxycodone, which is derived using thebaine, one of the compounds in opium, are described as semi-synthetic.
Benzodiazepines are used medically to reduce anxiety, help people sleep and to relax the body. They include diazepam or Valium, oxazepam or Serepax , alprazolam or Xanax and a number of other drugs. Taken in high doses or in conjunction with alcohol they are responsible for many overdoses. Taking these kinds of drugs in higher than prescribed quantities can slow your breathing to dangerous levels or stop it altogether. Mixing these drugs can be extremely dangerous.
People’s tolerance to a drug can drop quickly and for a variety of reasons, such as having not used for a while (eg: having been in custody or having done detoxification/rehabilitation) or cutting down.
Signs of depressant drugoverdose (e.g. heroin, morphine, oxycodone, fentanyl, methadone) include:
- shallow breathing or not breathing at all
- snoring or gurgling sounds (this can mean that a person’s airway is partly blocked)
- blue lips or fingertips
- floppy arms and legs
- no response to stimulus
- unrousable (can’t be woken up) unconsciousness.
If you can’t get a response from someone, don’t assume they are asleep. Not all overdoses happen quickly and sometimes it can take hours for someone to die. Action taken in those hours could save a life. This is a medical emergency: call the ambulance immediately if you can’t rouse them.
Generally people do not automatically think of alcohol when they think of overdose, but alcohol is a depressant and it is all too possible to overdose on it. Acute alcohol poisoning, which is usually a result of binge drinking, is an example.
Our bodies can process about one unit of alcohol an hour. If you drink a lot quickly the amount of alcohol in your bloodstream (blood alcohol concentration, or BAC) may become dangerously high, which can stop your body from working properly. In extreme cases, alcohol poisoning could stop you breathing, stop your heart or cause you to choke on your own vomit.
Signs of alcohol intoxication to the point of overdose include:
- loss of coordination
- irregular or slow breathing (less than eight breaths a minute)
- blue-tinged or pale skin
- low body temperature (hypothermia)
- stupor (being conscious but unresponsive)
- unconsciousness (passing out).
It is possible to overdose on amphetamines such as speed and ice. Amphetamine overdose increases the risk of heart attack, stroke, seizure or drug-induced psychotic episodes.
Amphetamine overdoses look different from an opioid OD, and signs and symptoms include:
- chest pain
- severe headache
- high temperature (overheating, but not sweating)
- difficulty breathing
- agitation and paranoia
Understanding tolerance and half-life
When a person uses a drug regularly they develop tolerance to it. This means they need to use more to get the same effect. Similarly, if a person hasn’t been using regularly – or if they’ve not been able to get drugs – their tolerance will drop. When people take their usual amount of drugs after a break from using, it could be too much for the body to cope with and lead to an overdose. This is why high-risk situations for drug overdose include post-release from prison, detoxification and rehabilitation. Someone on naltrexone can also be at risk if they use soon after stopping oral medication, or skipped a dose, or when the effects of a naltrexone implant have ceased.
“Half-life” refers to the time it takes for a drug to drop to half the strength of its original dose. Some drugs have a long half-life, for example some benzodiazepines. If a person has used yesterday, they may still have enough in their system today to overdose if they use more. Diazepam (Valium) has one of about 24 hours, so if you took 20mg yesterday you would still have approximately 10mg of diazepam active in your system today. If you were then to use heroin or morphine, you would have an increased risk of overdose as you would be using the opioids in addition to that 10mg of diazepam.