Toxicity Toxicity of<unk>  Animal studies comparing pure<unk>  to morphine showed it to have increased toxicity, more potent relief of pain, higher levels of sedation, decreased respiration, and increased digestive activity. Toxicity of "krokodil" Illicitly produced<unk>  is typically far from pure and often contains large amounts of toxic substances and contaminants as a result of the drug producers neglecting to remove highly toxic reactants and solvents left over from synthesis. This neglect could be due to the producers having a limited understanding of chemistry or as a way to avoid the costs of extracting the toxic material. Injecting any such mixture can cause serious damage to the skin, blood vessels, bone and muscles, sometimes requiring limb amputation in long-term users. Causes of this damage are associated with iodine, phosphorus and other toxic substances that are present after synthesis.<unk>  producers would use cheap, readily available but relatively toxic and impure solvents such as battery acid, gasoline or paint thinner during the reaction scheme, without adequately removing them afterwards before distribution. Strong acids and bases such as hydrochloric acid and sodium hydroxide are also employed without measuring the pH of the final solution, and analysis of leftover solutions of "krokodil" in used syringes showed the pH was typically less than 3 (i.e. as acidic as lemon juice). Failure to remove insoluble fillers and binding aids from the codeine tablets used as starting material, as well as co-administration with pharmaceuticals such as tropicamide and tianeptine, are also cited as possible contributors to the high toxicity observed in users. The frequent occurrence of tissue damage and infection among illicit users are what gained the drug its nickname of the flesh-eating drug, or the zombie drug as homemade versions made under inadequate conditions contain multiple impurities and toxic substances that lead to severe tissue damage and subsequent infection as a direct consequence of use. Gangrene, phlebitis, thrombosis (blood clots), pneumonia, meningitis, septicaemia (blood infection), osteomyelitis (bone infection), liver and kidney damage, brain damage, and HIV/AIDS are common serious adverse health effects observed among users of krokodil. Sometimes, the user will miss the vein when injecting the<unk> , creating an abscess and causing death of the flesh surrounding the entry-point. Reinforcement disorders Early medical trials of humans taking<unk>  have resulted in the finding that like morphine and most other analgesics of the morphine type, small amounts are highly addictive and tolerance to the drug develops quickly. However, though tolerance to respiratory depression with repeated doses was observed in rats, early clinical trials failed to show any tolerance to these same effects with repeated doses in humans.
Desomorphine
Apomorphine
Droperidol
Tripelennamine
Bocasan
Benzatropine
Bretylium
Tropisetron