Street drugs can be a source of endless frustrationfor emergency physicians and medical toxicologists who scramble to keep up with the drugs du jour. No sooner is one drug banned than another — similar but still legal — pops up to take its place.
Dab is one example. It's an extremely powerful form of marijuana, and it has more than a few aliases: amber, wax, butter, earwax, glass, shatter, and BHO (butane hash oil.) Dab contains upwards of 75–90 percent tetrahydrocannabinol (THC). Users say it will blow your mind.Home chemists say it also may blow you up.
Dab is manufactured by forcing a hydrocarbon solvent — usually butane — through a tightly packed mass of marijuana leaves, stems, and buds. The solvent extracts THC from the plant material, and the remaining resinous or waxy material after it is cooked can be smoked, vaporized, or ingested. It will, according to Rolling Stone magazine, make the user feel “cosmically baked.” (http://rol.st/1ePMibc.)
Of course, it doesn't take a genius to see a major problem here. Butane is extremely volatile and flammable. The vapor is heavier than air and tends to accumulate, especially in enclosed spaces. Dab is legal in Colorado for now, where it is manufactured under industrial conditions and sold in marijuana shops. But the seemingly straightforward extraction process has attracted many an amateur with a vision of “breaking dab” and becoming the Walter White of weed. A good number of these cooks have ended up in burn units after explosions destroyed their homes. The Los Angeles Times reported in January that at least 17 patients with severe injuries associated with cooking BHO had been admitted to burn centers in the Southern California area over the past 14 months.
The analogy to meth lab explosions is so obvious that “Breaking Dab” T-shirts are already for sale on the Internet, and our poison center has consulted on several patients who presented after using it. The important clinical point is that even regular consumers of marijuana (which usually contains about 20% THC) can't handle dab. The drug is so powerful that users may exhibit psychotic behavior lasting 24 hours or more. Prolonged observation and admission is often required.
Then there's gravel, a second-generation bath salt.It looks like a collection of small grayish-white stones, which gives it its name. It was just a little more than three years ago that we first heard about bath salts, psychotropic chemicals that were often labeled — with a wink — as “not for human consumption.” Intensive analytical work determined that the main ingredients in those first bath salts were the synthetic cathinones MDPV, methylone, and mephedrone,although these products could contain almost anything.
Last October, the Kingsport (TN) Times News reported that local police had dealt with nearly two dozen incidents involving people exposed to gravel.The drug samples they seized often contained adulterants such as methamphetamine and clonazepam, but the main ingredient was alpha-pyrrolidinopentiophenone (α-PVP), an analogue of MDPV. This was often sold as a purported plant fertilizer.
No cases of α-PVP toxicity have yet been reported in the medical literature, but severe paranoiais a characteristic finding in press accounts. Some patients also seem to be impervious to pain, making them difficult to restrain and control. α-PVP is a central nervous system and cardiovascular stimulant like all synthetic cathinones.
A scientific article in press sheds some light on the actions of α-PVP (Neuropharmacology 2014 Mar 2 [Epub ahead of print]). The authors note that MDPV is distinct from mephedrone and methylone because it has a five-sided nitrogen-containing pyrollidine ring. α-PVP contains this same ring, which blocks dopamine and norepinephrine reuptake. This resembles the pharmacologic mechanism of cocaine rather than amphetamine, mephedrone, or methylone, drugs that increase catecholamine release. The observable stimulant effects of all these drugs are similar, however, because the final result of both mechanisms is increased catecholamine levels in synapses.
As if dab and gravel weren't enough for EPs, there's also the mystery of the strange cocaine adulterant.I mused on that a few years ago, asking: Who put the veterinary worm medicine in cocaine? (EMN 2010;32:28; http://bit.ly/1jKlGZo.) The whodunitbegan when epidemiologists noticed a number of cases of agranulocystosis in cocaine users even though cocaine had not been previously associated with loss of white blood cells. Further investigation revealed that samples of cocaine used by these patients all contained levamisole, a dewormer used to treat large animals.
In fact, more than half of the cocaine samples intercepted coming into the United States contained levamisole. Why would anyone go to the trouble of obtaining this unusual adulterant and adding it to the cocaine supply, especially because it is far from benign? Exposure to levamisole has also been associated with some particularly nasty cases of necrotizing dermal vasculitis.
The mystery may have been solved. A laboratory investigation into the pharmacology of levamisole found that it is metabolized in aminorex, a stimulant marketed as a diet aid in Europe. These authors found that aminorex is a powerful inhibitor of dopamine and norepinephrine reuptake while levamisole is a weak one. Aminorex also increases release of serotonin. The resulting augmentation of catecholamine activity in the synapse may enhance and prolong the effects of cocaine. (Neurochem Int 2013 Dec 1 [Epub ahead of print].)