The Medical Complications of Drug Addiction and the Medical Assessment of the Intravenous Drug User: 25 Years Later

A quarter of a century ago, three articles [1-3] reviewed the medical complications of drug addiction. Previously, these complications were a novel clinical problem in a small subgroup of patients in municipal and county hospitals in our largest cities; however, they now occur frequently throughout this country and in other parts of the world. The emergence of human immunodeficiency virus (HIV) infection and the increase in cocaine abuse have added new dimensions to this problem. Despite this, few general reviews have been written [4]. Many questions from the original reviews remain unanswered (for example, the endocrine, hematologic, and immunologic sequelae of drug abuse). Our review is intended to provide a historical context to this vast subject. Methods Study Selection We performed a manual search of the internal medicine and subspeciality literature of the past three decades. Selected studies were of three typesbaseline studies for the period ending in 1968, subsequent studies (after 1968) that emphasized changes from baseline, and studies after 1968 that emphasized change (or the absence of change) and the manner in which clinicians conceptualized problems. Definition of Terms Intravenous drug user is now the preferred term instead of the previous, broad term of drug abuser. This term also places the focus on the major common cause of these medical complicationsneedle use. Although the term intravenous drug user excludes subcutaneous usage (see tetanus) and the inhalation route used for crack cocaine intoxication, we use it because of its connection with the major infectious disease complications. Certain drugs prevalent in the 1960s, such as intravenous methamphetamine (methedrine or speed), have returned. Others, such as cocaine in its various formsinhaled (powder and free-base), smoked (crack), and injectedhave expanded to become major parts of the current market. Heroin, which penetrated the inner city areas in the 1950s, remains the major drug abused by addicts currently admitted to drug-abuse treatment programs [5]. However, this may represent selection bias and may systematically underestimate cocaine and amphetamine use [6-8]. However, intravenous drug users are seldom drug purists. In addition to heroin or cocaine, they may inject other opiates available (methadone, hydromorphone [Dilaudid], morphine, or meperidine [Demerol]) and nonopiate drugs of other classes, with their unique side effects [9, 10]. A partial list of drugs of abuse and their street names is given in Table 1. Many new slang names and many new drugs that are now abused have appeared during the past 25 years. Table 1. Partial List of Street Names of Abused Drugs The Apparent Natural History of Intravenous Drug Use Experience suggests variability in the natural history of intravenous drug use, but as a disease archetype it is a useful pattern for predicting behavior. The following natural history of intravenous drug use emerges from multiple patient interviews and is consistent with what is reported by drug abuse counselors and in the literature [11, 12]. Intravenous administration is usually first tried in adolescence. At this time, the person, who may not yet have his or her own injection paraphernalia (works), may use a communal needle and syringe. He may also patronize shooting galleries where a common works is rented. Most transmission of hepatitis occurs within the first few years; we know less about when HIV transmission occurs, although it may be at the same time. As drug use increases and continues (late teens and early 20s), the person has his own works and shares it less and less, until a steady needle partner may be the only other person using the same hypodermic equipment. During their late 20s and early 30s, drug users often try to quit or to decrease drug use. They begin to enter rehabilitation programs voluntarily or are forced to do so by the court. Finally, in their late 30s and 40s, they may stop intravenous drug use. Some turn to other drugs, especially alcohol, or other oral agents (prescription or illegal). Some are abstinent for long periods only to relapse repeatedly, and some are weekend recreation intravenous drug users (one form of weekend chipper). Fifty- and 60-year-old intravenous drug users are not rare [8, 13]. The relapsing nature of intravenous drug abuse belies the notion of cure in this group of persons. Stars fall was the title used by a prominent English therapist writing about relapses in his patients who had previous stellar cures [14, 15]. By this reasoning, the abstinent are only in remission, a profoundly pessimistic view. Changes in the Injection Apparatus In the past two decades, the works [16] have been modernized. What began as a reusable, metal needle wedged onto a medicine dropper, with rolled paper as an adaptor, is now a disposable syringe with a disposable needle, both being reused. Proponents of the distribution of needles and syringes are not providing anything that is not already available [17]. However, they argue for providing them in new condition to decrease needle sharing, which might help decrease transmission of viral agents, although it will not decrease bacterial or fungal contamination of the skin or injected material. Counseling of intravenous drug users on improving their self-injection sterile technique has also been considered [18]. Cooking the material in a spoon or bottle cap to achieve solubility, using contaminated water, and improvising filters (cotton or cigarette filters) are practices that continue, along with the resulting infectious complications. Complications of Illicit Drug Use Skin and Superficial Structures Skin and soft tissue lesions, once the most common reason for emergency room visits by intravenous drug users, result from the nonsterile injections, sharing of equipment, poor personal hygiene, subcutaneous injection into deltoid muscles and thighs in the absence of an available vein, or injection into the veins of the neck or groin. Some active intravenous drug users have stigmata (scars due to old abscesses or track marks, a darkening of the skin over the antecubital veins, which is literally tattooing with carbon particles and other materials pushed under the skin). It is easy to understand how these repeated injections result in cellulitis, skin abscess, septic thrombophlebitis, necrotizing fasciitis, gas gangrene, pyomyositis [1, 2, 19-21], localized Fournier gangrene [22], lymphedema, or even infected, pulsatile pseudoaneurysms of the neck or groin [23-25]. The microorganisms involved in the skin and local vascular infections vary, but Staphylococcus aureus is the main agent, followed by various streptococci, aerobic gram-negative rods, anaerobic cocci, and bacilli [19-23]. The same range of organisms has been found in the metastatic bone and joint infections and the endocarditis of intravenous drug users. However, new and unique symptoms continue to be reported; a syndrome of severe dermatitis, eosinophilia, and dermatopathic lymphadenopathy has recently been described in two intravenous drug users with dual infection with HIV-I and human T-lymphotropic virus II [26]. Musculoskeletal Involvement To the rheumatologist, the complications of intravenous drug use cover a broad area [27], ranging from the transient rheumatologic prodrome of hepatitis B antigenemia [28] to chronic amyloidosis [29, 30]. One salient change in the past decades has been in the agents causing bone and joint infections in intravenous drug users [31-33]. Staphylococcus aureus has apparently replaced Candida species and gram-negative bacilli (in particular, Pseudomonas) as the primary cause of these infectionsnot unlike what occurred with endocarditis (see below). In the current setting of extensive cocaine abuse, there are reports of muscle and skin infarction [34] and of rhabdomyolysis after free-basing cocaine, sometimes with renal failure and shock after intravenous injection or inhalation of free-base cocaine (crack) or both [35-38]. A similar syndrome of rhabdomyolysis and shock has been reported due to intravenous methamphetamine or phenmetrazine use [39]. Rhabdomyolysis and myoglobinuria have also been reported with heroin and various other drugs [40-44]. Some cases were clearly due to pressure-induced crush injuries during a prolonged period of unconsciousness. Two unique reports, frequently cited in the literature, must be discussed. A report from Boston City Hospital, in the late 70s, of a musculoskeletal syndrome was associated with Brown Mexican heroin [45]. This syndrome was never reported again nor confirmed by clinical experience elsewhere. It was either a truly local phenomenon or an example of the hazard of asking leading questions of intravenous drug users. The other report [46] presented a syndrome of small middle vessel angiitis (which was disseminated and necrotizing) as a consequence of intravenous drug use. What was insufficiently emphasized was that most patients with this syndrome were intravenous users of methamphetamine. This drug abuse from the 1960s to early 1980s produced a considerable volume of literature [47-53] covering both cerebral and disseminated vasculitis as well as intracerebral hemorrhage and cerebral infarction. Some of these same findings were noted later when cocaine abuse spread, not surprisingly, because amphetamines and cocaine are sympathomimetic agents. Pulmonary Complications The nature of pulmonary complications has been greatly altered by the arrival of HIV (Table 2). Aside from Pneumocystis pneumonia [54], the opportunistic infections of HIV have had a smaller effect on hospital admissions of intravenous drug users than have the more frequent bacterial pneumonias. It had long been suspected, although never proven [1, 20, 44], that intravenous drug users were at greater risk for bacterial pneumonia. Although no difference appears to occur in progression to the acquired immunodeficiency syndrome (AIDS) between in