Rectal Route
The rectal route involves giving a drug through the rectum,
where it is absorbed by the rectal mucosa into the bloodstream. It is
useful when patients cannot take medicines by mouth, such as during vomiting,
unconsciousness, or difficulty swallowing. Drugs given by this route may
act locally in the rectum or produce a systemic effect after
absorption.
Definition
The rectal route of administration means introducing
a drug into the rectum, usually in the form of a suppository, enema,
or rectal solution, for local or systemic action.
Forms Used
- Suppositories
– solid, bullet-shaped preparations that melt at body temperature
- Enemas
– liquid preparations for cleansing or delivering medicine
- Rectal
gels or creams – for local application (e.g., hemorrhoids)
Advantages
- Useful
for unconscious, vomiting, or bedridden patients
- Avoids
destruction of the drug by stomach acid and enzymes
- Partially
avoids first-pass metabolism, improving drug effectiveness
- Suitable
for children and elderly patients
- Can
provide local action (for hemorrhoids or inflammation) or systemic
action (like fever or pain relief)
- Useful
when the oral route is not possible
Disadvantages
- Uncomfortable
and inconvenient for many patients
- Absorption
may be irregular or incomplete
- Irritation
of rectal mucosa may occur
- Difficult
to retain the drug for enough time
- Not
suitable for drugs that require precise dose control
Importance of Rectal Route
- Provides
an alternative route when oral administration is not possible:
When the patient cannot take medicines by mouth due to illness, surgery, or other reasons, rectal administration becomes a good alternative.
Example: Rectal suppositories are given to patients unable to swallow tablets after surgery. - Ensures
drug delivery in vomiting or unconscious patients:
Rectal route allows medicine to be absorbed even when the patient is vomiting or unconscious.
Example: Paracetamol suppositories are used to reduce fever in vomiting or unconscious children. - Helps
in pediatric and geriatric care:
This route is useful for children and elderly patients who have difficulty swallowing or are uncooperative.
Example: Glycerin suppositories are used as mild laxatives for children or bedridden elderly patients. - Offers
local treatment for rectal diseases such as piles or fissures:
Drugs can act directly on the affected rectal tissues, giving fast relief and promoting healing.
Example: Hydrocortisone suppositories or creams are used to reduce inflammation and pain in piles. - Can
provide systemic effects like fever or pain relief:
Some drugs administered rectally are absorbed into the bloodstream to produce body-wide effects.
Example: Diclofenac suppositories are used for systemic pain relief and to lower fever. - Avoids
gastric irritation and partial first-pass metabolism:
Drugs given rectally do not pass through the stomach, preventing irritation, and part of the drug escapes liver metabolism, improving absorption.
Example: Aspirin suppositories help patients with stomach ulcers avoid gastric irritation. - Important
in emergency or special medical situations:
In emergencies or when intravenous access is not available, rectal route offers a quick and effective option.
Example: Diazepam rectal gel is used to control seizures when IV access is not possible.
