Drugs and Their Effects


Find out how drugs and alcohol can affect you...

The Oxford Dictionary defines a drug as ‘a medicine or other substance which has a physiological effect when ingested or otherwise introduced into the body’. In addition to regulated prescription and un-regulated illicit drugs, coffee and tobacco are also considered drugs as they have an effect on the body when consumed.

Information on some of the more common drugs detected is outlined below:

Cannabis (Marijuana)

Marijuana is the most commonly used of all illicit drugs and subsequently the most commonly detected in a drug and alcohol testing program.

Cannabinoids are derived from the plant Cannabis sativa. Marijuana is the dried leaves, flowers and stem of the plant. Hashish consists mainly of the resin from the flower clusters on the female plant. It is usually either smoked or ingested in food or liquids such as tea.

Common names used for cannabinoids are marijuana, dope, pot, herb, weed, grass, ganja, mary-jane and hash. The main active ingredient in cannabis that produces a ‘high’ is called delta-9-tetrahydrocannabinol, or more commonly THC(9).

The effects of cannabis in the body can last from two to six hours.

The side effects listed below make it dangerous to use cannabis at work, particularly if the employee is operating heavy machinery or driving a vehicle. There is also a greater risk of an accident occurring due to the poor performance of even simple manual tasks.

Regular cannabis users may start to exhibit signs of loss of energy and interest in their tasks, causing their performance to suffer. They may also find it difficult to learn new work skills. Family and relationship problems may can be caused or made worse by involvement with cannabis. Legal problems may also occur as it is an illegal substance and may come to the attention of police, subsequently receiving fines and associated criminal convictions.

In common with other psychoactive drugs, the effects of cannabis depend on the dose, the individual and environment.

Short Term Effects of Cannabis

Cannabis is known to cause the following:

  • Short term memory problems
  • Impaired thinking
  • Loss of balance and coordination
  • Decreased concentration
  • Changes in sensory perception
  • Impaired ability to perform complex tasks
  • Decreased alertness
  • Disinhibition.

Long Term Effects of Cannabis

Regular and continued use of cannabis may cause or contribute to a number of health problems including:

  • Respiratory difficulties – cannabis smoke contains many substances which irritate the airways, and many smokers tend to hold the smoke in for longer which aggravates respiratory problems
  • Increased risk of cancers of the lung, mouth, throat and tongue as cannabis contains a number of carcinogens (cancer-causing agents)
  • Cannabis dependence syndrome – characterised by a variety of cognitive, physical and behavioural symptoms, such as inability to control use; continued use despite problems, withdrawal and tolerance
  • Increased risk of psychotic symptoms resulting in anxiety, panic reactions or paranoia
  • Cannabis dependence reduces fertility in both men and women.

Tolerance and Dependence of Cannabis

Cannabis dependence and tolerance are quite common among regular uses of cannabis. Tolerance means the user requires more cannabis to achieve the same effects they used to get with smaller amounts. Dependence, or addiction, means cannabis has become central in their life, they may spend much of their time thinking about cannabis and obtaining it, they may have trouble controlling their use, or continue to use cannabis despite experiencing problems.

Dependent users who abruptly stop their cannabis use may have mild withdrawal symptoms such as sleep disturbance, anxiety and irritability.

Cannabis and Driving

Performance of complex tasks such as driving motor vehicles is impaired after smoking even small amounts of marijuana. Higher doses result in poor performance of simple manual tasks. The degree of impairment depends on the amount of cannabis consumed.

The use of cannabis and alcohol together, or separated by a few hours, besides making some of the unpleasant effects of both drugs much worse (e.g. nausea), can severely impair driving. These effects on driving of the two drugs taken together are considerably greater than the effects of either substance taken alone.

Testing for Cannabis

THC and other compounds from cannabis can be detected in the blood and urine for some time after marijuana has been used. These compounds can be stored in body fat, to be gradually excreted from the body. For infrequent users of marijuana, a single occasion of use may be detectable in the urine for several days. Long-term heavy users of marijuana may have cannabis compounds detectable in their urine for many weeks after their last use of cannabis. However, it is difficult to determine how recently a person has used cannabis from blood or urine tests.

The time that it takes before the average person will stop testing positive for THC is extremely variable and dependent on several factors. THC is the only one of the illicit drugs that is stored in the fat tissue, so it can take longer to be cleared from the system. Every individual has a different body size and shape and metabolism, which are all factors in how quickly the drug will be eradicated.

The concentration of THC can also vary greatly between plants, from 1-30% of the total dry weight, thus a person who ingests or smokes marijuana with a very high THC level will probably take longer than someone who has taken marijuana with a low THC level to clear the drug from their system. It is very dependent on how much an individual has smoked, how often, what they have smoked and how long they have been smoking for.

Usually someone who has one dose of marijuana and is not a common smoker it would probably take between 1-4 days to be cleared from the system, but for a very heavy and constant smoker it can take up to 4 weeks. For a very heavy and constant smoker, with some form of metabolic disorder, i.e. Hepatitis C, it can take up to 8 weeks.

Synthetic Cannabinoids (synthetic cannabis)

Synthetic cannabis is a psychoactive herbal and chemical product which, when consumed mimics the effects of cannabis. It is best known by the brand names Kronic, K2 and Spice, terms which have largely become generic trademarks used to refer to any synthetic cannabis product. A type of synthetic cannabis sold in Australia is known as Kronic. Synthetic cannabis compounds are now illegal across Australia.

When synthetic cannabis blends first went on sale in the early 2000s it was thought they achieved an effect through a mixture of legal herbs. Laboratory analysis in 2008 showed this was not the case and that they in fact contained synthetic cannabinoids which act on the body in a similar way to cannabinoids naturally found in cannabis, such as THC. A large and complex variety of synthetic cannabinoids, most often cannabicyclohexanol, JWH-018, JWH-073 or HU-210, are used in an attempt to avoid the laws which make cannabis illegal, making synthetic cannabis a designer drug.

Effects of Synthetic Cannabis

No official studies have been conducted on its effects on humans. Though its effects are not well documented, extremely large doses may cause negative effects that are generally not noted in marijuana users, such as increased agitation and vomiting.

Testing for Synthetic Cannabis

A number of on-site synthetic cannabis urine drug test kits are now available. Ask for independent laboratory analysis to ascertain the accuracy of the device used.

Laboratory testing for synthetic cannabinoids is also available using liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) for oral fluid and liquid chromatography/high resolution/mass spectrometry (LC/HR/MS) for urine.

Because synthetic cannabis is not part of the Australian Standards, testing for synthetic cannabis (and the levels of detection) need to be included in your policy.


Call Medvet on 1800 633 838 for more information about testing for synthetic cannabis at your workplace.


8.9% of Australians have tried amphetamines in their life, with 3.4% having used them in the last 12 months. However, 22% of 20-29 year olds have tried amphetamines and 4.8% have used them in the last month, which is well above the national average.

Amphetamine and methamphetamine are chemically very similar in structure. They are usually made in backyard laboratories, and are therefore of varying strength and purity. Many other substances can be mixed in with amphetamines such as other drugs, sugar, glucose, bicarbonate of soda and ephedrine. They are usually taken by mouth, intranasal (by 'snorting'), smoking or via injection.

Other common names for amphetamines or methamphetamines are aped, up, fast, louee, goey, whiz, pep pills, crystal meth, ice, shabu and uppers. They usually come in either a white to brown powder form, capsules, tablets, crystals or red liquid and include the ‘ecstasy’ type drugs.

Amphetamines are synthetic central nervous system stimulants. Their action mimics that of the human hormone adrenaline.

Short Term Effects of Amphetamines

Short term effects of amphetamines can include:

  • A rush which includes speeding up of bodily activities such as heart rate, breathing and blood pressure. The mouth can dry up, sweating increases and headaches can occur
  • Feeling more energetic and alert, increased confidence and reduced appetite
  • Irritability, anxiety, depressive, hostile and aggressive behaviours. Panic attacks can also occur
  • Strokes, heart failure, seizures and high body temperatures as a result of overdose and the impure nature of most amphetamines
  • Feelings of violence, tension, radical mood swings, depression and total exhaustion when coming down from the ‘high’. Coming down can also cause shaking and feelings of nausea.

Long Term Effects of Amphetamines

The long term effects of amphetamine misuse can be:

  • Chronic sleeping problems
  • Anxiety, paranoia and depression, possibly even psychosis
  • High blood pressure and an irregular heartbeat
  • Malnourishment due to long term loss of appetite
  • Aggressive tendencies
  • Immune system damage from lack of sleep and malnourishment, leading to reduced resistance to infections.

Testing for Amphetamines

Amphetamines can be detected via oral fluid or urine.

Amphetamines can take varying time to be cleared from the body, depending on factors such as potency of the drug taken, weight, metabolism, amount of drug taken, whether the person has taken other drugs and the environment that the person is taking the drug in. Usually it will take between 1-2 days for the drug to be cleared from the system enough to be able to pass a drug test.


Cocaine is not a commonly used drug in Australia, with only 4.4% of people having tried it and 0.4% of people being current users of the drug.

Cocaine hydrochloride is derived from the leaves of the Coca bush. It is usually either a fine white/cream powder or in small rock like forms ("crack" cocaine). It is taken by sniffing or snorting, injecting and smoking.

Cocaine is a powerful central nervous system stimulant rapidly absorbed and transmitted to the brain.

Short Term Effects of Cocaine

Short term effects of taking cocaine include:

  • A short high - usually 15-30 minutes if the cocaine is snorted, or 5-10 minutes after smoking the cocaine
  • Intense and immediate high typified by hyper-stimulation, reduced fatigue and mental clarity. Restlessness, irritability and anxiety
  • Poor concentration and judgement
  • Inhibition of normal feelings of tiredness
  • Constricted peripheral blood vessels, dilated pupils and increased temperature, heart rate and blood pressure.

Long Term Effects of Cocaine

  • Paranoia, psychosis and hallucinations
  • Unpredictable and aggressive behaviour
  • Insomnia
  • Depression and anxiety upon withdrawal from taking the drug
  • Ulceration of the mucous membrane of the nose and can damage the nasal septum and cause it to collapse
  • Smoking can cause lung damage, coughing and chest pain, and injecting can cause damage to the veins, tetanus, abscesses and damage to the heart, lungs, liver and brain, and can potentially lead to contracting hepatitis and HIV.

Many cocaine/amphetamine users also use benzodiazepines in conjunction so as to induce sleep after drug use. Usually a cocaine user will take 12 hours to 3 days to test negative to a drug test after ceasing use.


Opiates are drugs that briefly stimulate the higher centres of the brain and then depress activity of the central nervous system. This alters the messages going to and from the brain and body, slowing physical, mental and emotional responses. They are used medicinally to relieve pain. They can include natural and synthetic forms. Natural opiates, such as codeine and morphine, are derived from the opium extracted from the seedpod of the Asian poppy. Other drugs such as heroin are further processed from morphine and others from codeine.


Codeine is usually in the form of an over the counter pain killer such as Panadeine or Nurofen Plus, or can be prescribed by a Doctor as a severe pain reliever such as Oxycontin or Mersyndol. Painkillers such as these are commonly abused by the Australian public, with 3% recently using analgesics for non-medicinal purposes.

Impairment effects can include drowsiness, diminished response time and respiratory depression. Addiction to severe pain killers can develop.


Heroin is not a widely used drug in Australia, approximately 2.3% of people have tried heroin, and 0.5% of people are current users.

Heroin is made from morphine or codeine (which is derived from the opium poppy) by using a chemical process. It is often of varying potency and usually includes other substances that are used to 'cut' the drug. Heroin is usually injected into a vein, but can also be smoked or snorted.

Heroin is highly addictive, both physically (the body undergoes a strong withdrawal from each hit, but adapts to heroin and becomes used to functioning with the drug present) and psychologically (emotional dependence).

Short Term Effects of Heroin

The short term effects of using heroin include:

  • An intense surge of euphoria
  • Diminishing feelings of physical pain, hunger and sexual urges
  • Central nervous system depression including breathing, blood pressure and pulse becoming slower, dry mouth and increasing drowsiness
  • Nausea and vomiting can occur, particularly in cases of overdose

Long Term Effects of Heroin

The long term effects of using heroin can include:

  • Collapsed veins, infection of the heart lining and valves, abscesses, cellulitis, and liver disease as well as pulmonary complications including various types of pneumonia. This is often because of poisonous additives to the heroin when it is cut.
  • Constipation, menstrual irregularity and infertility in women, and loss of sex drive in men
  • HIV and Hepatitis B and C are common health problems for injecting heroin users after being contracted via unsafe sharing of needles

Heroin has a short half-life in the body, and the high commonly lasts from 15 minutes to 4 hours. It will usually take about 12-24 hours for most of the heroin to be eradicated from the body.


Benzodiazepines are prescribed and used commonly in Australia as sleeping tablets or muscle relaxants (i.e. anti-anxiety or sedative type medication e.g. Valium).

Benzodiazepines are usually prescribed, so there is very little of the drug available that has not been produced in regulated and hygienic situations. Benzodiazepines are most often prescribed in tablet or capsule form. They are usually taken orally or injected.

Short Term Effects of Benzodiazepines

If taken according to directions, benzodiazepines should have the following effects:

  • Relaxation, calmness and relief from tension and anxiety
  • Sometimes side effects such as drowsiness, tiredness, dizziness and lethargy can occur
  • Blurred or double vision, impairment of thought processes including depression and memory, vertigo and stuttering can occur
  • If higher doses are taken over-sedation can occur leading to drowsiness or sleep.

Long Term Effects of Benzodiazepines

Long term benzodiazepine use can cause:

  • Difficulty sleeping and disturbing dreams
  • Nausea, headaches, skin rash, sexual problems, menstrual problems, weight gain, greater appetite and increased risk of accidents
  • Drowsiness, lack of motivation, difficulty thinking clearly, memory loss, and may even cause such side effects as personality change, changes in emotional response and anxiety problems.

Testing for Benzodiazepines

Benzodiazepines can be detected in oral fluid or urine, however benzodiazepines are not included as part of the AS 4760 Standard. If you are using oral fluid testing for your drug and alcohol program and want to include testing for benzodiazepines, it is important you include this drug and associated detection levels in your drug and alcohol policy.

Depending on the dose and amount of time that benzodiazepines have been taken for, it will usually take approximately 1-4 days for the drugs to be cleared from the system.


Alcohol is the most widely used, psychoactive, or mood changing, recreational drug in Australia and is part of most social occasions.

Alcohol is a central nervous system depressant – not a stimulant as most people think. The effect of alcohol depends on:

  • How much alcohol is consumed
  • How quickly the alcohol is consumed
  • Whether it is consumed with other drugs
  • Whether the person is used to drinking
  • The person’s mood
  • The person’s age, weight, sex and general health status.

Short Term Effects of Alcohol

Depressant drugs affect concentration and coordination and slow response times to unexpected situations.

After a few drinks the effects are:Three Beers

  • People feel more relaxed
  • Reduce concentration
  • Slower reflexes.

After a few more drinks:

  • Fewer inhibitions
  • More confidence
  • Reduced coordination
  • Slurred speech
  • Intense moods e.g. sad, happy, angry.

As more alcohol is consumed, the following effects may occur:

  • Increased confusion
  • Blurred vision
  • Poor muscle control
  • Nausea
  • Vomiting
  • Sleep
  • Worst case scenario is coma or possibly death.

Long Term Effects of Alcohol

Heavy consumption of alcohol over time can cause damage to many parts of the body. Impairment of brain and liver functions can be permanent. If diet is also poor, their health may be further affected. Emotional difficulties such as depression and relationship problems are also likely.

Testing for Alcohol

Testing for alcohol should be with an AS 3547 compliant breathalyser.