As with other drugs, the medical complications of heroin may vary depending on the individual, frequency of use, amount of dosage, and/or prior medical attributes.
Heroin use can lead to addiction, a chronic relapsing problem attendant to repeated drug use that has the potential for causing neurochemical and molecular changes in the brain as well as instigating behavior change.
Withdrawal symptoms are most noticeable between 24 and 48 hours after the last dose of heroin and can include restlessness, muscle and bone pain, insomnia, diarrhea, vomiting, cold flashes with goose bumps, and leg movements. Users sometimes describe withdrawal as being similar to a bad case of the flu. The symptoms usually subside after a week but there has been evidence showing that the symptoms may be persistent for many months.[1,2] Heroin users rarely die from withdrawal.
Chronic use or abuse of heroin can lead to long lasting and deleterious impairments on intellectual functioning.[3-5] The negative effects on brain functioning may include a decrease in working memory, episodic memory, and decision making.[3,4] In addition, active heroin addicts may exhibit poor impulse control, planning, decision making, verbal functioning, and visual-spatial analysis.[3,5]
Injecting is a particularly common route of administration among heroin users. This is a concern because additives in street heroin may not dissolve readily. As a result, injecting heroin can contribute to the clogging of the blood vessels that lead to the lungs, liver, kidneys, and brain. Collapsed veins, cellulitis, and abscesses are common problems among chronic injection heroin users. In Arizona, most of the heroin used is a dark gummy form of the drug called black tar heroin. This form of the drug may be especially problematic because it is less refined and cheaper than white powder heroin and is frequently mixed with different adulterants such as dextrose, burned cornstarch, instant coffee, and sometimes dirt. As a result of the mixing process, bacterial spores may be introduced to the final product. In addition, since black tar heroin is predominantly injected, repeated IV injections can cause vascular sclerosis and lead the injectors to inject subcutaneously or intramuscularly. As a result, a series of infections grouped as necrotizing fasciitis can form and become lethal.
Some short term effects associated with heroin smoking (inhaling heroin vapors) may include leukoencephalopathy, reduced pulmonary function, dyspnea, and status asthmaticus.
Poor health of heroin users and the depressing effects heroin causes on respiration are contributing factors to pulmonary complications including various types of pneumonia.
Recent studies have reported that peripheral immunomodulatory functions are influenced by opiates. Exogenous opiates, such as heroin, tend to repress diverse immune functions. The depression of the immune system along with poor nutritional status, intravenous drug use, poly drug use, and unsanitary housing can lead to the problems of cutaneous and systemic infections often seen in heroin users.
Along with abscesses and cellulitis, endocarditis is also reported in injection drug users (IDUs) abusing heroin. Endocarditis predominantly appears on the right side, often involving the lungs.
Infections of the Liver
The risks for acquiring hepatitis B, C, and A are increased in heroin users who administer the drug intravenously. In general, hepatitis B and C may occur due to sharing of contaminated drug injecting equipment. Hepatitis A, which is typically transmitted in the general population by the normal fecal-oral route, may be transmitted among heroin users due to poor hygiene in the preparation of the drug.
Blood born viruses
HIV is also a serious concern, particularly among injection drug users. Sharing of needles, along with other injecting equipment and an increase in risky sexual behaviors (e.g. prostitution) contribute to the transmission of HIV.