A Guide to the Different Routes of Drug Administration

types of drugs with different routes of administration

Not only are there several drugs out there including both legal and illegal substances, but also there are numerous different ways to administer these drugs as well as pros and cons to each.

Different Types of Drug Administration for Medicinal Use & Abuse

How drugs are taken can impact the intensity of their effects, how quickly the effects are felt, and in terms of prescription medicine, their efficacy. Because of these differences, prescription medications and illegal drugs alike can come in many forms.

Medicinal drugs come with specific instructions for the modes of drug administration in order to avoid complications and ensure they work the way they are designed to, but illicit drug users may alter a drug in order to take it in a way that leads to a faster and stronger high.

Some of the different routes of drug administration include:

  • Oral- through the mouth
  • Injection- administered with a needle
  • Nasal- snorted through the nose
  • Inhalation- inhaled through the mouth and sometimes nose
  • Transdermal- absorbed through the skin
  • Ocular– absorbed through the eye
  • Otic- through the ear
  • Rectal or vaginal- inserted in the rectum or vagina


Taking drugs orally is one of the most common ways of drug administration for both medicinal use and drug abuse. Several prescription medications and over-the-counter drugs come in pill form that can be swallowed or chewed. There are also some drugs that are placed under the tongue (sublingually) or between the gums and cheek (buccally) for faster absorption.

Because these medications can sometimes be addictive, people who misuse them may start to regularly abuse these drugs. Other illicit substances such as Ecstacy and PCP may also come in pill form. For drug users, oral administration may not produce as powerful highs, but it is a less threatening type of drug administration.


Injection is another popular route of drug administration for both illicit substances and medicinal purposes. Drugs can be injected into the muscle (intramuscular), beneath the skin (subcutaneously), or into a vein (intravenously).

Intravenous drug injection is popular among drug users because it leads to a faster high and is often done with heroin. Although drug users enjoy more immediate effects with this method, skin infections like abscesses from iv drug use are possible as well as several other serious health problems.


Nasal drug administration is when drugs are taken through the nose. Some over-the-counter or prescription medicines come in nasal sprays for this purpose. Other illicit drugs like often cocaine are snorted in powder form through the nose for a fast high. This route of drug administration can lead to serious damage to not just the nose, but the respiratory system as a whole.


Inhalation is a route of drug administration that is not as common. It is sometimes administered with a machine so the dosage can be better regulated and is often used for drugs that act directly on the lungs. Some people have also taken to inhaling chemicals from household products like cleaners in a process nicknamed huffing. Huffing is extremely dangerous and can lead to immediate death from suffocation or heart failure.


Transdermal drug administration is when drugs are applied to and absorbed through the skin. These types of drugs typically come as a patch and can be used for a variety of medicinal purposes. Transdermal drugs are growing in use in the medical field because of how they decrease the risk of damage to the liver and gastrointestinal system.1

Although not as common as other routes of drug administration, some transdermal drugs like fentanyl patches can be abused.


Some medicine administration is done through the eye. These drugs can come in the form of eye drops, gels, or ointment and are typically used to treat the eye directly. Ocular drug abuse is not common.


Similar to ocular drug administration, otic drug administration is most commonly used to administer medicine directly to the ear. It is also not a common route of administration for drug abuse.

Rectal or Vaginal

Some drugs may also be absorbed through the rectum or vagina. The rectum has a high number of blood vessels and a thin surface layer, so substances are absorbed quickly in this manner.

While these medicinal drugs come in the form of suppositories, other drugs may be taken in this manner as well in a process called boofing. People can boof a variety of different substances including cocaine and alcohol, but there are many dangers of taking drugs anally that are not designed for this purpose.


There are several different routes of drug administration out there, but abusing and misusing drugs in any way can be dangerous. If you or someone you love is struggling with substance abuse, get help. Drug rehabs are designed to assist people in overcoming this abuse and moving forward. Contact us today to learn more.

1. NCBI - Transdermal Medications

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