"Unga", a highly addictive heroin-based drug, has reached a tipping point across communities of the Western Cape, and is now a major drug of choice on the Cape Flats.
According to Grant Jardine, director of the Cape Town Drug Counselling Centres, the build-up of unga in low-income communities has been a gradual one, but this year has marked the turning point.
"For the first few months of this year," he says, "heroin was our number one presenting drug for the first time.
"This indicates that heroin use is definitely on the increase amongst people in the disadvantaged areas that we serve, but the attention has all landed on tik which has masked the rise of heroin."
According to Andreas Pluddemann, a senior scientist at the Medical Research Council's Alcohol and Drug Abuse Research Unit, "Five years ago, heroin was found mainly in the middle class".
"But that has all changed, and it is now highly prevalent in lower socio-economic groups in the form of unga."
At the same time, the age at which people are experimenting with drugs is younger, says Jardine, and while the percentage of youngsters trying drugs is also higher, the type of drugs they are using has also changed to harder, more addictive ones like heroin.
Lara Foot-Newton, who directed Addicted to Life - an interactive theatre production aimed at school learners in high-risk communities, says that during every performance of her play, when the narrator says that it is not just about tik because in years to come, there will be something to replace it, the learners in the audience shout out "unga".
But, she adds, the name of a specific drug "gets hype just like a brand name, and the word spreads really quickly, but the real problem here is the general culture of substance and alcohol abuse".
Jardine says that, as a result, "just targeting tik is ineffective because in a few years, it is going to be something else and then something else."
Lionel Newton, who was instrumental in the field research for the script of Addicted to Life, says that "one of the reasons it is flooding the market is because of the war in Afghanistan where the heroin comes from, and this in turn means that unga is far more readily available and cheaper".
Pluddemann says it is also cheaper because it is sold in smaller units, and is less concentrated and of a poor quality.
"The price difference between tik and unga is now relatively small," he says, "and the street value of a unit of unga is just R30 or R40."
The two drugs, however, are not competing for a market but are in fact exacerbating the use of each other.
Says Pluddemann, "Unga is marketed as a good agent to accompany tik because it has the opposite effect.
"Tik keeps you on a high and awake for hours, so people need something to bring them down and help them sleep. And so heroine too becomes more popular."
Jardine says such combinations of substance use are highly common.
"It is extremely rare that someone with a substance abuse problem uses only one drug. One often has a 'drug of choice' but it is rare that that will be the only drug she or he is using."
Cape Flats rapper "Hoppie", who was once an addict but now uses his music to speak out against substance abuse, says he was part of the Cape Flats drug culture for seven consecutive years, and that during that time, he never just used one type of drug.
"I was part of a world where dagga, mandrax, ecstasy, rocks, tik and heroin were nothing unusual, an during that time I did so many things I am not comfortable with and which I now regret."