Drug A - Z


Opiates (sometimes called ‘narcotic analgesics’) include morphine, codeine, pethidine, heroin and opium. Opiates are ‘depressant’ drugs. Depressant drugs do not necessarily make you feel depressed. Rather, they slow down the activity of the central nervous system and messages going to and from the brain and the body. This includes physical, mental and emotional responses.

The effects of any drug vary from person to person.  It depends on many factors including an individual’s size, weight and health, how the drug is taken, how much is taken, whether the person is used to taking it, the person’s mood and whether other drugs are taken.  The effects also depend on the environment in which the drug is used – for example, whether the person is alone, with others, or in a social setting.

Immediate effects

  • a rush of intense pleasure and a strong feeling of wellbeing
  • feelings of pain, hunger or sexual urges may diminish
  • breathing, blood pressure and pulse become slower, pupils of the eyes also get much smaller, mouth dries out.
  • drowsiness – as the amount used increases, the user may feel warm, heavy and sleepy
  • nausea and vomiting can occur

In greater quantities

The above immediate effects intensify and last longer with higher quantities of heroin.  As the quantity used increases, the following effects are also likely to occur:

  • poor concentration
  • sleeping (‘on the nod’)
  • shallower and slower breathing
  • nausea and vomiting
  • sweating, itching and increased urinary output

Long-term effects

  • constipation
  • menstrual irregularity and infertility in women
  • loss of sex drive in men
  • loss of appetite, malnutrition
  • greater susceptibility to infections

If a dependent person suddenly stops taking opiates, or severely cuts down the amount they use, they will experience physical withdrawal symptoms because their body has to readjust to functioning without the drug. This usually occurs within a few hours after last use.

Withdrawal symptoms include a craving for the drug, restlessness, yawning, tears, diarrhoea, low blood pressure, stomach and leg cramps, vomiting, goose bumps, and a runny nose. These withdrawal symptoms get stronger and usually peak around 2 to 4 days after last use.

They also include increased irritability, insomnia, loss of appetite, elevated heart rate, and emotional depression. Then they begin to get weaker and usually subside after 6 to 7 days. However, some symptoms, such as chronic depression, anxiety, insomnia, loss of appetite, periods of agitation and a continued craving for the drug, may last for periods of months and even years.

Overdose may occur if:

  • too much opiate is used, or it is a strong batch
  • it is used with alcohol or sedatives (benzodiazepines).

Remember with these drugs – especially synthetic opioids – if you have never used before, you only need a very small amount.  Overdose with these drugs is particularly dangerous as it can cause death.  Breathing becomes very slow (and in some instances stops), body temperature drops, and heartbeat becomes irregular.


People who are physically dependent on opiates usually develop tolerance to the drug, making it necessary to take more and more to get the desired effects. Eventually, a usage plateau is reached, at which no amount of the drug is sufficient. When this level is achieved, dependent users continue to administer the drug, but largely for the purpose of delaying withdrawal sickness.


Dependence on opiates can be psychological, physical, or both.

Psychological dependence: People who are psychologically dependent on opiates find that using it becomes far more important than other activities in their lives. They crave the drug and will find it very difficult to stop using it, or even to cut down on the amount they use.

Physical dependence: Physical dependence occurs when a person’s body adapts to the opiate and the body gets used to functioning with the drug present. For some people this dependence leads to bad eating habits, poor hygiene and housing problems. Poor nutrition and living conditions increase the risk of infections and other health problems. Maintaining the ‘habit’ can sometimes lead to users turning to crime to get enough money to pay for it.

Morphine is most generally available as morphine sulphate tablets in various strengths from 10mg to 200mg, or as capsules, and may be taken orally. These can also be processed for use by injecting subcutaneously, intramuscularly, or intravenously; the last is the route preferred by those who are dependent on morphine.

Codeine is usually taken orally but can be injected intramuscularly or subcutaneously. The intravenous route is usually not used as reactions such as facial swelling, pulmonary edema and convulsions can occur.

Homebake is made by converting codeine-based pharmaceuticals into morphine. It is either sold as a liquid ready for injection or as crystals which are dissolved and injected.

Pethidine can be taken orally, injected, and sniffed. It is unknown if smoking is possible.

Heroin is fairly rare and expensive in New Zealand and, when available, is usually white or off white powder. Most heroin in NZ originates in SE Asia. Heroin is most commonly injected into a vein. It can also be smoked (‘chasing the dragon’) or snorted.

Opium from poppies can be smoked.

Heroin is a Class A drug. The maximum penalty for importation/ manufacture/supply is life imprisonment and for possession 6 months jail and/or $1000 fine.
Morphine (including homebake) and Opium are Class B drugs. The maximum penalty for importation/ manufacture/supply is 14 years imprisonment and for possession 3 months jail and/or $500 fine.

Codeine is a Class C drug. The maximum penalty for importation/ manufacture/supply is 8 years imprisonment and for possession 3 months jail and/or a $500 fine.

It is illegal to drive a motor vehicle while under the influence of any drug, including opiates. Breaking this law carries heavy penalties including disqualification from driving, fines and even imprisonment. It is advised that you do not drive after the consumption of any mood altering substance. You could put your own and other people’s life at serious risk.

Like all drugs, opiates may have the potential to cause harm to the unborn child and also harm to the baby whilst breastfeeding. Due to this, it is recommended to not use any level of opiates during pregnancy and whilst breastfeeding.