Introduction
We take medications to diagnose, treat, or prevent illness. They come in lots of different forms and we take them in many different ways. You may take a drug yourself, or a healthcare provider may give it to you.
Drugs can be dangerous, though, even when they’re meant to improve our health. Taking them correctly and understanding the right way to administer them can reduce the risks. Read on to learn the importance of using medication as directed.
There are several different ways drugs can be administered. You’re probably familiar with injections and pills that you swallow, but medications can be given in many other ways as well.
Routes of medication administration are described in the table below.
The route used to give a drug depends on three main factors:
- the part of the body being treated
- the way the drug works within the body
- the formula of the drug
For instance, some drugs are destroyed by stomach acid if they’re taken by mouth. So, they may have to be given by injection instead.
Not all types of medications can be administered at home or by someone without special training. Doctors, nurses, and other healthcare providers are trained in how to give you medication safely.
Administration of medication requires thorough understanding the drug, including:
- how it moves through your body
- when it needs to be administered
- possible side effects and dangerous reactions
- proper storage, handling, and disposal
Healthcare providers are trained in all of these issues. In fact, many healthcare providers keep in mind the “five rights” when they administer drugs:
- the right patient
- the right drug
- the right time
- the right dose
- the right route
Medication errors happen all too often in the United States, even when drugs are given by professionals. The Food and Drug Administration receives more than 100,000 reports of medication errors annually through its MedWatch program. These errors can take place when:
- prescribing a drug
- entering the drug or dosage information into a computer system
- a drug is being prepared or dispensed
- a drug is taken by or given to someone
The “rights” are a starting point in helping to make sure that medications are given correctly and safely.
It’s important to take only the dosage described in the prescription label or other instructions. Dosage is carefully determined by your doctor and can be affected by your age, weight, kidney and liver health, and other health conditions.
For some medications, dosage must be determined by trial and error. In these cases, your healthcare provider would need to monitor you when you first start treatment.
For example, if your doctor prescribes thyroid medications or blood thinners, you would likely need to have several blood tests over time to show if the dosage is too high or too low. The results from these tests would help your doctor adjust your dosage until they find the one that’s right for you.
Many medications need to reach a certain level in your bloodstream to be effective. They need to be given at specific times, such as every morning, to keep that amount of drug in your system.
Taking a dose too soon could lead to drug levels that are too high, and missing a dose or waiting too long between doses could lower the amount of drug in your body and keep it from working properly.
Adverse events, or unwanted and negative effects, can happen with any drug. These effects can include an allergic reaction or an interaction with another drug you’re taking.
To help avoid these problems, be sure to tell your doctor about any other medications you’re taking or any times you’ve had an allergy to drugs or foods.
A drug with high risk of adverse effects may be administered only by a healthcare provider. And in some uncommon cases, your healthcare provider may keep you in their facility so they can observe how the drug affects you.
If you take a medication yourself, it’s up to you to watch for problems, such as a rash, swelling, or other side effects. If you notice any problems, be sure to let your doctor know.
Be sure to take your medications correctly to get the most out them and to reduce your risk of side effects and other problems. Anyone giving you the drug should follow your doctor’s instructions carefully.
Make sure that you understand everything about taking your medication. If you have any questions, talk to your doctor. Some questions you might ask include:
- I’m not sure how often I should take this medication. Can you explain your instructions more clearly?
- My nurse gives me my medication now. Can I be trained to give it to myself?
- I’m having trouble taking my medication. Can a family member or healthcare provider give it to me instead?
- Are there any side effects I should watch for?
- What time of day should I take this drug? Or does it matter?
- Am I taking any medications that this drug could interact with?
par•en•ter•al (pa ren′tər əl),USA pronunciation adj. [Anat., Med., Physiol.]
- Anatomy, Medicine, Physiologytaken into the body in a manner other than through the digestive canal.
- Anatomy, Medicine, Physiologynot within the intestine;
not intestinal.
- par- + enter- + -al1 1905–10
parenteral /pæˈrɛntərəl/ adj
- (esp of the route by which a drug is administered) by means other than through the digestive tract, esp by injection
- designating a drug to be injected
On this page:
What is the digestive system?
The digestive system is made up of the gastrointestinal tract—also called the GI tract or digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus. The liver, pancreas, and gallbladder are the solid organs of the digestive system.
The small intestine has three parts. The first part is called the duodenum. The jejunum is in the middle and the ileum is at the end. The large intestine includes the appendix, cecum, colon, and rectum. The appendix is a finger-shaped pouch attached to the cecum. The cecum is the first part of the large intestine. The colon is next. The rectum is the end of the large intestine.
Bacteria in your GI tract, also called gut flora or microbiome, help with digestion. Parts of your nervous and circulatory systems also help. Working together, nerves, hormones, bacteria, blood, and the organs of your digestive system digest the foods and liquids you eat or drink each day.
Why is digestion important?
Digestion is important because your body needs nutrients from food and drink to work properly and stay healthy. Proteins, fats, carbohydrates, vitamins, minerals, and water are nutrients. Your digestive system breaks nutrients into parts small enough for your body to absorb and use for energy, growth, and cell repair.
- Proteins break into amino acids
- Fats break into fatty acids and glycerol
- Carbohydrates break into simple sugars
MyPlate offers ideas and tips to help you meet your individual health needs.
How does my digestive system work?
Each part of your digestive system helps to move food and liquid through your GI tract, break food and liquid into smaller parts, or both. Once foods are broken into small enough parts, your body can absorb and move the nutrients to where they are needed. Your large intestine absorbs water, and the waste products of digestion become stool. Nerves and hormones help control the digestive process.
The digestive process
| Chewing |
| Peristalsis |
| Upper muscle in stomach relaxes to let food enter, and lower muscle mixes food with digestive juice |
| Peristalsis |
| None |
| None |
| Peristalsis |
How does food move through my GI tract?
Food moves through your GI tract by a process called peristalsis. The large, hollow organs of your GI tract contain a layer of muscle that enables their walls to move. The movement pushes food and liquid through your GI tract and mixes the contents within each organ. The muscle behind the food contracts and squeezes the food forward, while the muscle in front of the food relaxes to allow the food to move.
Mouth. Food starts to move through your GI tract when you eat. When you swallow, your tongue pushes the food into your throat. A small flap of tissue, called the epiglottis, folds over your windpipe to prevent choking and the food passes into your esophagus.
Esophagus. Once you begin swallowing, the process becomes automatic. Your brain signals the muscles of the esophagus and peristalsis begins.
Lower esophageal sphincter. When food reaches the end of your esophagus, a ringlike muscle—called the lower esophageal sphincter —relaxes and lets food pass into your stomach. This sphincter usually stays closed to keep what’s in your stomach from flowing back into your esophagus.
Stomach. After food enters your stomach, the stomach muscles mix the food and liquid with digestive juices. The stomach slowly empties its contents, called chyme, into your small intestine.
Small intestine. The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine, and push the mixture forward for further digestion. The walls of the small intestine absorb water and the digested nutrients into your bloodstream. As peristalsis continues, the waste products of the digestive process move into the large intestine.
Large intestine. Waste products from the digestive process include undigested parts of food, fluid, and older cells from the lining of your GI tract. The large intestine absorbs water and changes the waste from liquid into stool. Peristalsis helps move the stool into your rectum.
Rectum. The lower end of your large intestine, the rectum, stores stool until it pushes stool out of your anus during a bowel movement.
Watch this video to see how food moves through your GI tract.
How does my digestive system break food into small parts my body can use?
As food moves through your GI tract, your digestive organs break the food into smaller parts using:
- motion, such as chewing, squeezing, and mixing
- digestive juices, such as stomach acid, bile, and enzymes
Mouth. The digestive process starts in your mouth when you chew. Your salivary glands make saliva, a digestive juice, which moistens food so it moves more easily through your esophagus into your stomach. Saliva also has an enzyme that begins to break down starches in your food.
Esophagus. After you swallow, peristalsis pushes the food down your esophagus into your stomach.
Stomach. Glands in your stomach lining make stomach acid and enzymes that break down food. Muscles of your stomach mix the food with these digestive juices.
Pancreas. Your pancreas makes a digestive juice that has enzymes that break down carbohydrates, fats, and proteins. The pancreas delivers the digestive juice to the small intestine through small tubes called ducts.
Liver. Your liver makes a digestive juice called bile that helps digest fats and some vitamins. Bile ducts carry bile from your liver to your gallbladder for storage, or to the small intestine for use.
Gallbladder. Your gallbladder stores bile between meals. When you eat, your gallbladder squeezes bile through the bile ducts into your small intestine.
Small intestine. Your small intestine makes digestive juice, which mixes with bile and pancreatic juice to complete the breakdown of proteins, carbohydrates, and fats. Bacteria in your small intestine make some of the enzymes you need to digest carbohydrates. Your small intestine moves water from your bloodstream into your GI tract to help break down food. Your small intestine also absorbs water with other nutrients.
Large intestine. In your large intestine, more water moves from your GI tract into your bloodstream. Bacteria in your large intestine help break down remaining nutrients and make vitamin K. Waste products of digestion, including parts of food that are still too large, become stool.
What happens to the digested food?
The small intestine absorbs most of the nutrients in your food, and your circulatory system passes them on to other parts of your body to store or use. Special cells help absorbed nutrients cross the intestinal lining into your bloodstream. Your blood carries simple sugars, amino acids, glycerol, and some vitamins and salts to the liver. Your liver stores, processes, and delivers nutrients to the rest of your body when needed.
The lymph system, a network of vessels that carry white blood cells and a fluid called lymph throughout your body to fight infection, absorbs fatty acids and vitamins.
Your body uses sugars, amino acids, fatty acids, and glycerol to build substances you need for energy, growth, and cell repair.
How does my body control the digestive process?
Your hormones and nerves work together to help control the digestive process. Signals flow within your GI tract and back and forth from your GI tract to your brain.
Hormones
Cells lining your stomach and small intestine make and release hormones that control how your digestive system works. These hormones tell your body when to make digestive juices and send signals to your brain that you are hungry or full. Your pancreas also makes hormones that are important to digestion.
Nerves
You have nerves that connect your central nervous system—your brain and spinal cord—to your digestive system and control some digestive functions. For example, when you see or smell food, your brain sends a signal that causes your salivary glands to "make your mouth water" to prepare you to eat.
You also have an enteric nervous system (ENS)—nerves within the walls of your GI tract. When food stretches the walls of your GI tract, the nerves of your ENS release many different substances that speed up or delay the movement of food and the production of digestive juices. The nerves send signals to control the actions of your gut muscles to contract and relax to push food through your intestines.
Clinical Trials
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions.
What are clinical trials, and are they right for you?
Watch a video of NIDDK Director Dr. Griffin P. Rodgers explaining the importance of participating in clinical trials.
What clinical trials are open?
Clinical trials that are currently open and are recruiting can be viewed at www.ClinicalTrials.gov.