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Injection Drug Use


Gerald F. O’Malley

, DO, Grand Strand Regional Medical Center;

Rika O’Malley

, MD, Grand Strand Medical Center

Medically Reviewed Dec 2022
Topic Resources

Drugs may be swallowed, smoked, inhaled through the nose as a powder (snorted), or injected. When drugs are injected, their effects may occur more quickly, be stronger, or both.

Drugs may be injected into a vein (intravenously), a muscle (intramuscularly), or under the skin (subcutaneously). Veins in the arms are typically used for intravenous injections, but if these areas become too scarred and damaged, some people inject drugs into other veins, including those of the thigh, neck, armpit or feet.

Complications of Injection Drug Use

Injecting a drug has more risks than other methods of use. People are exposed not only to the effects of the drug but also to problems related to injection itself, such as the following:

Diagnosis of Injection Drug Use

  • A doctor's evaluation

  • Sometimes self-reporting

Sometimes injection drug use is diagnosed when people go to a health care practitioner because they want help stopping use of the drug. Other people try to hide their drug use.

Practitioners may suspect problems with drug use when they notice changes in mood or behavior in a person. They may then do a thorough physical examination. Signs of drug abuse may be apparent. For example, repeatedly injecting drugs intravenously produces track marks. Track marks are lines of tiny, dark dots (needle punctures) surrounded by an area of darkened or discolored skin. Injecting drugs under the skin causes circular scars or ulcers. People who inject drugs may claim other reasons for the marks, such as frequent blood donations, bug bites, or other injuries.

Health care practitioners also use other methods (such as questionnaires) to identify abuse of some drugs and other substances and to determine the extent of drug use and its effects. Urine and sometimes blood tests may be done to check for the presence of drugs.

Treatment of Injection Drug Use

  • Counseling

  • Prevention and treatment of infectious complications

Specific treatment depends on the drug being used, but it typically involves counseling and sometimes involves use of other drugs (for example, methadone as a safer drug to replace heroin). Family support and support groups help people remain committed to stopping use of the drug.

Treatment of complications is the same as that for similar complications with other causes. For example, abscesses may be drained, and antibiotics may be used to treat infections.

Because sharing needles is a common cause of HIV infection Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome (AIDS). HIV is transmitted... read more Human Immunodeficiency Virus (HIV) Infection and hepatitis Overview of Hepatitis Hepatitis is inflammation of the liver. (See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.) Hepatitis is common throughout the world. Hepatitis can be Acute (short-lived) read more , a harm-reduction movement was started. Its purpose is to reduce the harm of drug use in users who cannot stop. Thus, users are provided clean needles and syringes so they do not reuse others’ needles. This strategy helps reduce the spread (and the cost to society) of HIV infection and hepatitis.

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

  • National Institute on Drug Abuse (NIDA): Federal agency that supports scientific research into drug use and its consequences and supplies information about commonly used drugs, research priorities and progress, clinical resources, and grant and funding opportunities.

  • Substance Abuse and Mental Health Services Administration (SAMHSA): US Department of Health agency that leads public health efforts to improve behavioral health and provides resources, including treatment locators, toll-free helplines, practitioner training tools, statistics, and publications on a variety of substance-related topics.

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