A number of drugs of abuse are given by injection to achieve a more rapid or potent effect or both. Drugs are typically injected IV but may be injected subcutaneously, IM, or even sublingually. Users typically access peripheral veins, but when these have sclerosed due to chronic use, some learn to inject into large central veins (eg, internal jugular, femoral, axillary).
People who inject illicit drugs risk not only the adverse pharmacodynamic effects of the drugs but also complications related to contaminants, adulterants, and infectious agents that may be injected with the drug.
Some drug users crush tablets of prescription drugs, dissolve them, and inject the solution IV, thus injecting themselves with an array of filler agents commonly present in tablets, including cellulose, talc, and cornstarch. Filler agents can become trapped by the pulmonary capillary bed and result in chronic inflammation and foreign body granulomatosis. Filler agents can also damage the endothelium of heart valves, thus increasing the risk of endocarditis. Infective Endocarditis Infective endocarditis is infection of the endocardium, usually with bacteria (commonly, streptococci or staphylococci) or fungi. It may cause fever, heart murmurs, petechiae, anemia, embolic... read more
Street drugs such as heroin Opioid Use Disorder and Rehabilitation “Opioid” is a term for a number of natural substances (originally derived from the opium poppy) and their semisynthetic and synthetic analogues that bind to specific opioid receptors. Opioids... read more and cocaine Cocaine Cocaine is a sympathomimetic drug with central nervous system stimulant and euphoriant properties. High doses can cause panic, schizophrenic-like symptoms, seizures, hyperthermia, hypertension... read more are often “cut” with various adulterants (eg, amphetamines Amphetamines Amphetamines are sympathomimetic drugs with central nervous system stimulant and euphoriant properties whose toxic adverse effects include delirium, hypertension, seizures, and hyperthermia... read more , clenbuterol, dextromethorphan, fentanyl, ketamine Ketamine and Phencyclidine (PCP) Ketamine and phencyclidine are dissociative anesthetics that can cause intoxication, sometimes with confusion or a catatonic state. Overdose can cause coma and, rarely, death. Ketamine and phencyclidine... read more , levamisole, lidocaine, lysergic acid diethylamide [LSD] Hallucinogens Hallucinogens are a diverse group of drugs that can cause highly unpredictable, idiosyncratic reactions. Intoxication typically causes hallucinations, with altered perception, impaired judgment... read more , pseudoephedrine, quinine, scopolamine, xylazine). Adulterants may be added to enhance mind-altering properties or to substitute for pure drug; their presence can make diagnostic and therapeutic decisions difficult.
Needle sharing and use of nonsterile techniques can lead to many infectious complications. Injection site complications include cutaneous abscesses Cutaneous Abscess A cutaneous abscess is a localized collection of pus in the skin and may occur on any skin surface. Symptoms and signs are pain and a tender and firm or fluctuant swelling. Diagnosis is usually... read more , cellulitis Cellulitis Cellulitis is acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci or staphylococci. Symptoms and signs are pain, warmth, rapidly spreading erythema... read more , lymphangitis Lymphangitis Lymphangitis is acute bacterial infection (usually streptococcal) of peripheral lymphatic channels. (See also Overview of Bacterial Skin Infections and Lymphadenitis.) Typical causes of lymphangitis... read more , lymphadenitis Lymphadenitis Lymphadenitis is an acute infection of one or more lymph nodes. Symptoms include pain, tenderness, and lymph node enlargement. Diagnosis is typically clinical. Treatment is usually empiric.... read more , and thrombophlebitis. Distant focal infectious complications due to septic emboli and bacteremia include bacterial endocarditis Infective Endocarditis Infective endocarditis is infection of the endocardium, usually with bacteria (commonly, streptococci or staphylococci) or fungi. It may cause fever, heart murmurs, petechiae, anemia, embolic... read more and abscesses in various organs and sites. Septic lung emboli Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. Risk factors for pulmonary embolism are... read more and osteomyelitis Osteomyelitis Osteomyelitis is inflammation and destruction of bone caused by bacteria, mycobacteria, or fungi. Common symptoms are localized bone pain and tenderness with constitutional symptoms (in acute... read more (particularly lumbar vertebral) are particularly common. Infectious spondylitis and sacroiliitis may occur.
Systemic infectious diseases are primarily hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more B and C and HIV infection Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection results from 1 of 2 similar retroviruses (HIV-1 and HIV-2) that destroy CD4+ lymphocytes and impair cell-mediated immunity, increasing risk of certain... read more . IV drug users are at high risk of pneumonia Overview of Pneumonia Pneumonia is acute inflammation of the lungs caused by infection. Initial diagnosis is usually based on chest x-ray and clinical findings. Causes, symptoms, treatment, preventive measures, and... read more , resulting from aspiration or hematogenous spread of bacteria. Other infections that are not directly caused by drug injection but are common among IV drug users include tuberculosis Tuberculosis (TB) Tuberculosis (TB) is a chronic, progressive mycobacterial infection, often with a period of latency following initial infection. TB most commonly affects the lungs. Symptoms include productive... read more , syphilis Syphilis Syphilis is caused by the spirochete Treponema pallidum and is characterized by 3 sequential clinical, symptomatic stages separated by periods of asymptomatic latent infection. Common manifestations... read more , and other sexually transmitted diseases Overview of Sexually Transmitted Diseases Sexually transmitted diseases (STDs), also termed sexually transmitted infections (STIs), can be caused by a number of microorganisms that vary widely in size, life cycle, the diseases and symptoms... read more . Even botulism Botulism Botulism is poisoning that is due to Clostridium botulinum toxin and that affects the peripheral nerves. Botulism may occur without infection if toxin is ingested, injected, or inhaled. Symptoms... read more and tetanus Tetanus Tetanus is acute poisoning from a neurotoxin produced by Clostridium tetani. Symptoms are intermittent tonic spasms of voluntary muscles. Spasm of the masseters accounts for the name lockjaw... read more can result from IV drug abuse.
Some patients readily admit to injection drug use, but for others, a thorough physical examination is needed to detect evidence of injection.
Chronic IV drug use can be confirmed by observing track marks due to repeated injections into subcutaneous veins. Track marks are a linear area of tiny, dark punctate lesions (needle punctures) surrounded by an area of darkened or discolored skin due to chronic inflammation. Track marks are often found in easily accessible sites (eg, antecubital fossa, forearms), but some drug users try to hide evidence of their injections by choosing less obvious sites (eg, axillae).
Subcutaneous injection (skin popping) can cause characteristic circular scars or ulcers; there may be signs of previous abscesses. Addicts may deny stigmata of drug use by attributing track marks to frequent blood donations, bug bites, or previous trauma.
Drug users, especially those with a history of injection drug use, should be thoroughly evaluated for viral hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more , HIV infection Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection results from 1 of 2 similar retroviruses (HIV-1 and HIV-2) that destroy CD4+ lymphocytes and impair cell-mediated immunity, increasing risk of certain... read more , and the wide range of other infectious diseases common among these patients (eg, tuberculosis, syphilis, other sexually transmitted diseases). Also, vaccination Overview of Immunization Immunity can be achieved Actively by using antigens (eg, vaccines, toxoids) Passively by using antibodies (eg, immune globulins, antitoxins) A toxoid is a bacterial toxin that has been modified... read more to prevent hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more , influenza Influenza Vaccine Based on recommendations by the World Health Organization and the Centers for Disease Control and Prevention (CDC), vaccines for influenza are modified annually to include the most prevalent... read more , pneumococcal infections Pneumococcal Vaccine Pneumococcal disease (eg, otitis media, pneumonia, sepsis, meningitis) is caused by some of the > 90 serotypes of Streptococcus pneumoniae (pneumococci). Vaccines are directed against many of... read more , tetanus infection Tetanus-Diphtheria Vaccine A vaccine for tetanus alone is available, but the tetanus vaccine is typically combined with those for diphtheria and/or pertussis. The vaccine for diphtheria is available only in combination... read more , and other infections should be offered to all appropriate patients.
The AIDS epidemic has triggered a harm-reduction movement, which aims to reduce the harm of drug use without necessarily requiring cessation. For example, providing clean needles and syringes for users who cannot stop injecting drugs reduces the spread of HIV and hepatitis.
Treatment of infectious complications is the same as that for similar infections resulting from other conditions; it includes use of antibiotics and incision and drainage of abscesses. Treatment may be complicated by difficulty obtaining venous access (and keeping the patient from using it to inject more drugs) and by poor adherence to treatment regimens.