Little Fly Wing: a new drug of concern in Argentina

A form of crude cocaine base known as ‘paco’ has been the ‘drug of the poor’ in Argentina for more than a decade 1. Paco typically contains adulterants such as inactive sugars, caffeine, local anesthetics (e.g. lidocaine) and stimulants (e.g. ephidrine), as well as production by-products (e.g. kerosene, soda ash). During the last few years, phenacetin has been detected as an adulterant to paco. Some of these adulterants pose the threat of serious short- and long-term health consequences independent of the negative health effects of cocaine, although there is insufficient research to quantify the nature and extent of such effects for most of these adulterants, phenacetin being an exception 2-6. During the last year, a new version of cocaine—Little Fly Wing—has been identified, and is causing as much concern as paco. It is produced in crystalline form, and is sniffed or injected. In comparison to paco [typically sold at 10 pesos (~ US$ 1) per ‘hit’], Little Fly Wing sells for 300–500 Argentine pesos (~ US$ 30–50) per gram. Although assay data are unavailable, a newspaper article by the Chairman of the Anti-Drug Association of Argentina 7 and an interview with the head of the Chemical Laboratory, Chemical Precursors and the Technical Office of the former Dangerous Drugs of Santa Fe province, Argentina 8 indicate that it is composed of ±80% cocaine hydrochloride and ±20% phenacetin. While prevalence data are lacking, reports about consumption are occurring in the media and from patients entering treatment. Cocaine has both short- and long-term deleterious effects. It causes pulmonary (e.g. heart palpitations to heart failure) and neurological problems (e.g., seizures to strokes), with a heightened risk of various psychological problems, including addiction 9. Due to the high amount of cocaine hydrochloride in Little Fly Wing (±80%), the nerve cells release abnormally large amounts of dopamine, more than are released by typical forms of freebase or crack cocaine, with significant deleterious effects on executive functioning, emotions and memory. Phenacetin causes hemolysis: destruction of red blood cells. This is caused by an immunocomplex formation mechanism. Antibodies are formed against the drug, which leads to the formation of immune complexes that are absorbed over the red blood cells membrane, which then activates the complement triggering hemolysis. This cascade usually produces an acute intravascular hemolysis, often with renal failure and thrombocytopenia 10. Phenacetin was once used in analgesic preparations, but has been found to be associated with an increased risk of carcinogenesis (e.g. urinary tract cancers), cardiovascular diseases, renal failure and certain blood disorders (e.g. methemoglobinemia), with its concomitant risk of shock, seizures and even death 11-13. These issues led to its withdrawal from the market by the US Food and Drug Administration (FDA), the United Kingdom, Sweden and Japan. It is still available in Argentina 14. Thus, this new preparation of a highly pure cocaine combined with phenacetin found in Little Fly Wing may pose a risk of morbidity and mortality equal to the risk posed by paco or crack cocaine for individuals who use it in Argentina or any other country where it may become popular. Public health surveillance systems should begin monitoring for the appearance of Little Fly Wing, and research on the nature and extent of its deleterious effects is needed urgently. None.