When we visit a doctor for any disease condition, we are prescribed few medicines which are to be taken by specific routes. These routes include
- Oral route
- Topical route (skin, eyes, ears)
- Inhalation route
- Parenteral route (injections)
- Vaginal route
- Anal route.
- Sub-lingual route.
These routes are called as routes of medication administration.
You might have mostly got tablets to consume but at times even syrups, ointments and even injections are given. You can also read types of dosage forms for more.
Some are taken by mouth (orally), some by skin application (ointment) while others into body muscles (injections). But why do doctors need this many routes of medication administration?
This is quite interesting and is studied as part of pharmacology course in medicine.
Routes of medication administration
Oral route ( also called per oral)
In this route as the name indicates drug is taken by mouth. It is safer and also inexpensive. It is the most common route of taking drugs.
Dosage forms like the tablets, capsules, syrups, suspensions, emulsion are taken by this route.
This route is preferred due to advantages like
a. Ease of administration as even the patient can take medicine on his own without others help.
b. The chances of taking improper dose is absent.
c. This is non-painful route and also safest route.
d. Also dosing by this route allows no wastage of drug.
d. It is suitable for people of all ages including infants, children, adults and old age people.
But it also has few limitations like
a. It is not possible to give drugs in this route to patients who are not awake or conscious.
b. Not all drugs can be given by this route due to chance of degradation in the liver before showing its actions.
c. In case of emergency this route is not preferred as the time taken by medicament given by this route to produce effect is half and hour to one hour. That is there is no immediate response.
Ex: Tablets, syrups, capsules are given by this route.
This route is where the medicament is applied on to skin to produce its effects. This route is one of the safest route as the drug cannot product adverse effects as it does not reach the systemic circulation (blood in the body). In this method of administration, drug is applied on to skin, mucus or any other body surfaces.
a) It can show local effect. I.e. the drug acts only at the site of application and not on whole body like in oral route.
Ex: Powders, ointments, lotions etc.
Here drugs are given by nose. The drugs are in gaseous form and allowed to be inhaled by the patient into the lungs.
After reaching the lungs, the drugs reach systemic circulation.
Examples: Some volatile anesthetics used in surgery are given by inhalation route. The patient inhales the anesthetic which reaches the brain and makes him lose the consciousness.
This is meant either for cleaning of poisons from stomach or for delivery of nutrition to the body bypassing mouth.
Parenteral route (other than intestine)
As the name indicates, here the drugs are given in routes other that intestine.
For this the drug in the form of liquid is taken into a sterilized or disposable syringe. Then the air drop if any a removed and the drug injected to the patient by piercing the needle into the tissue.
All types of injections come under this route. This route is less frequently used by doctors due to technical help required. But still this route has advantages over oral route.
This route is again divided into
- Intra-muscular (Injection into the muscle)
- Intra-venous (Injection into the veins)
- Sub-cutaneous (injection below the skin)
Advantages of this parenteral route.
- It is suitable to for emergency medical help.
- It helps to administer drugs even to patients in coma.
- For quick action and achieving immediate response in the patient the medicament is given directly into blood vessels.
- Also small amount of drug is needed compared to other routes as there is no wastage of drugs by metabolism.
- Those drugs which are not absorbed by stomach or which get digested by gut are given by this route.
Ex: Insulin in diabetic patients.
Disadvantages of this route:
1. Risky route: This route is risky as once drug is given, it cannot be retrieved back or stopped easily.
2. Pain and wounds: This route can induce pain during the injection also frequent injections can cause wound or abscesses.
3. Expensive route: One needs a syringe, cotton, sterilizing agent before administering the injection. So this adds up the cost.
4. Minimal chances of self medication. The patient cannot take the drug on his own in most cases.
This route is possible only in women. Also most of the times, this route is avoided. This is used for local infection in the genital parts of women.
This route of drug administration involves, passing of medicament into anus to affect the large intestine. This is called as enema and very useful in cases like irritable bowel syndrome, fistula, piles.
In this route, the tablet is kept below the tongue. The tablet dissolves slowly releasing the drug which is absorbed into the blood of the buccal cavity.
Glyceryl trinitrate which is used in case heart strokes is taken by this method.
This method is preferred for this drug because, it avoid first pass metabolism in liver and also the action starts fast. Further, the patient can take it on his own.