Published on June 20, 2026
Have you ever wondered why you swallow a tiny aspirin pill for a headache, but you have to go to a clinic to get a shot of a vaccine? Or why some asthma medications come as inhalers? Medicines are administered in ways that ensure that they work safely, effectively, and when needed. Some medicines can be administered through different routes.
Oral Administration
Swallowing a pill, capsule, or syrup is the most common way to take medicines. Once swallowed, the medicine travels to the stomach and small intestine, where it dissolves and is absorbed into the bloodstream. From there, it reaches the liver before finally circulating to the rest of the body. Taking an oral medication is highly convenient and cost-effective. However:
Oral medicines take time to work, usually 30 to 90 minutes. Therefore, they are not the ideal choice for emergencies.
Some oral medicines are partly or completely destroyed by stomach acid or liver enzymes before they ever reach the bloodstream. For example, insulin gets destroyed in the stomach and can therefore not be given orally. The antipsychotic drug asenaprine gets destroyed by the liver if it is given orally. Therefore, the tablet is placed below the tongue from where it gets absorbed directly into the blood stream.
People who are unconscious cannot be administered oral tablets.
Injections
When a drug cannot survive the digestive tract, or in case of an emergency, doctors turn to injections. Not all injections are administered the same way. Some medicines such as insulin are injected just below the skin, while others such as flu shots are injected into the muscle. Several emergency medicines and fluids are injected into the vein.
Inhalation
For respiratory conditions like asthma, inhalers and nebulizers are often preferred. These turn medications into a fine mist or powder that patients breathe, enabling the medications to reach directly into the lungs, and avoiding side effects to other parts of the body.
Topical (Creams/Ointments) and Patches
Creams and ointments are applied directly to the skin or mucous membranes to treat a local issue. For example, an antifungal cream is used to treat a fungal infection of the skin. Very little enters the bloodstream. On the other hand, patches (like nicotine or fentanyl patches) are stuck to the skin and release a steady, controlled dose of medicine through the skin and into the bloodstream over a few days.
Disclaimer: The information provided in this site is for informational purposes only. It is not intended to replace the advice of a doctor or healthcare professional, or the relationship that exists between a patient/site visitor and his/her existing physician. Always consult your doctor or other qualified healthcare provider for any medical condition, procedure, or treatment.