What is cannabis?

Cannabis is a plant that has three species. Cannabis sativa is the species that produce chemicals known as cannabinoids. The major cannabinoid of cannabis is ?-9-tetrahydrocannabinol (THC) and is the main psychoactive substance that contributes to the hallucinogenic effect of cannabis. Cannabis is the most widely cultivated, trafficked and abused illicit drug in the world. It is one of the drugs that is abused in Malaysia and make up 16% of the local drug addict population. The term ‘marijuana’ is often used to refer to cannabis leaves or other crude plant material while ‘hashish’ refers to the resin extracted from the flowers of the plant. Cannabis is listed in the Dangerous Drugs Act 1952, which ban the cultivation, production, distribution, import, export, possession and misuse of this drug.

Cannabis LeavesCannabis Leaves

Street Names of Cannabis That are Popular Among Drug Addicts in Malaysia

  • Ganja
  • Grass
  • Sayur
  • Tarek daun
  • Indian hemp
  • Barang weed
  • Joints
  • Sticks
  • Hashish
  • Dope
  • Pot
  • Weed

Symptoms of Cannabis Misuse

  • Increase in pupil size
  • Lack of concentration and judgement
  • Candy addiction
  • Increased appetite
  • Laughing for no reason

Effects of Cannabis Misuse on Health

Cannabis abuse can result in increased heart rate, loss of short term memory, always in anxious condition, respiratory tract and lung damage and addiction while prolonged use can result in psychotic disorders. When used during pregnancy it may cause impaired foetal development.

Synthetic Cannabis

Synthetic cannabis is a herb spiked with chemicals that result in similar psychoactive effects to marijuana. It may cause symptoms of addiction similar to cannabis. It is legally sold in some countries with names such as Spice, K2, No More Mr Nice Guy. Synthetic Cannabis contain chemicals called cannabimimetics that can cause harmful effects to health. It has potential to be abused because of similar effects to marijuana. This synthetic drug is not tested for its safety. In 2012, the U.S poison centre received five reports on the harmful effects of the synthetic cannabis.

The Effects of Synthetic Cannabis Misuse

Synthetic cannabis consumption produced symptoms similar to marijuana. Symptoms observed are as follows:

  • Always in anxious condition
  • Fast heart rate and high blood pressure
  • Nausea and vomiting
  • Muscles cramps and chills
  • Hallucinations and psychotic disorders
  • Suicidal and self-harming thoughts

Cannabis (THC) Metabolism

Cannabis can be taken into the body by inhalation and smoking. This route of intake allows quick diffusion of cannabis through the nasal passages and lungs into the blood. The metabolism of THC occurs in the liver. The main metabolite of THC formed in liver is 11-hydroxy-THC. In regular users, cannabinoids can be detected in blood between 12-24 hours after administration into the body. The lipid-soluble cannabinoid is retained longer than other drugs in our body.

Excretion of Cannabis

The main metabolite of cannabis excreted in urine is 11-nor-THC-carboxylic acid. THC can be detected longer in urine than other water-soluble drugs such as amphetamine and morphine. Detection period is up to 20-28 days after consumption. Specimen for THC testing should be sent immediately to the testing laboratory in Pathology Department, Ministry of Health because it is not stable at high temperatures. The specimen should be sent in ice. If the specimen cannot be sent immediately, it should be stored at 2-8 ?C or frozen if storage is more than three days.

Detection of Cannabis Misuse

Cannabis abuse can be detected by doing a drug test to detect 11-nor-THC-carboxilic acid in urine. There are two main categories of urine drug testing that is screening and confirmatory.

Screening Test

Screening tests are initial, qualitative drug tests conducted to identify classes of drugs present in the urine. Immunoassay based on the principle of competitive binding is the common technique used. Urine drug screening test kits are available as on-site tests or laboratory analysis. Rapid test are often used as on-site tests and are used in clinics and by law enforcers. The screening test result rely on a set threshold cut off value. Cut-off is a concentration to distinguish a positive or negative results. Specimens with concentrations above or equal to the cut-off are considered positive whole those with concentrations lower than the cut-off are considered negative. Screening test cut-off for THC is 50 ng/ml. Screening tests are not specific for the drug tested and therefore for legal or medico-legal purposes, all positive screened specimens have to be retested using confirmatory test methods.

Alat perubatan immunoassay yang digunakan dalam ujian saringan cannabis di hospital KKMAn immunoassay instrument that is used in KKM hospitals for the analysis of drug of abuse screening tests

Confirmation Test

Confirmatory tests are used to confirm a positive screened result. Confirmatory test is able to determine the presence of specific drugs in urine. Confirmatory test is mostly done using chromatographic techniques. The common chromatography techniques used to confirm THC are Gas Chromatography Mass Spectrometry (GCMS) and Liquid Tandem Mass Spectrometry (LC/MS/MS).

Gas Chromatography Mass SpectrometryGas Chromatography Mass Spectrometry (GCMS)

Liquid Chromatography Tandem Mass SpectrometryLiquid Chromatography Tandem Mass Spectrometry (LC/MS/MS)


  3. Garis Panduan Ujian Pengesanan Dadah Dalam Air Kencing.Pekeliling KPK Bil. 6/2002
  4. Peat, M.A. and Peat J.J. Cannabinoids: Abused Drugs Monograph Series, Abbott Laboratories, Diagnostic Division, Texas, 1994.
  5. WHO 2014 Management of substance abuse
  6. Bulletin AADK 2013
Last Reviewed : 04 January 2016
Writer : Dr. Norlida bt. Harun
Accreditor : Dr. Raja Elina bt. Raja Aziddin