this class is brief discussion for under graduate examination purpose

1. Dr. RAGHU PRASADA M S
MBBS,MD
ASSISTANT PROFESSOR
DEPT. OF PHARMACOLOGY
SSIMS & RC.
1

2. Enteral routes
Oral
Sublingual
Rectal
Parentral routes
Intra venous
intra muscular
intra peritonial
Intrathecal
intramedullary
Intra-arterial
Intra-articular
Subcutaneous
Intracardiac
Epidural
Inhalational
Transdermal
Topical route
Conjunctival, nasal
Auditory, vaginal
Urethral
Inunction
Dermal

3. 1. Commonest, Convenient , Cost effective
2. No Skill required, Self medication, Safest,
Sterilization is not required
3. Acceptable, Less Adverse effects compared to
parenteral route
4. Painless,
5. Large volume (doses) can be given
Both for systemic /local effects in G.I.T (All effects)
For local effect e.g. neomycin (an aminoglycoside),
anthelmintics, antiamoebic.

4. 1. Absorption varies (delay, decrease, or increase )
2. affected by food or drugs that affect GI motility
e.g. antimuscarinic, opioids )
3. Dose may not accurately be delivered
4. Irritation of gastric mucosa
5. Patient compliance not ensured
6. First pass metabolism/Presystemic elimination -
Metabolism of drug (to inactive form) after
administration before it reaches the systemic
circulation.
Greater the first pass effect, lesser will be the
bioavailability

5. Not suitable for Unconscious patients, Vomiting
patients, Emergency --- (Slow onset of action)
Following drugs can not be given by oral route:
Drugs destroyed by Stomach pH -benzyl penicillin)
Drugs destroyed by Intestinal enzymes (e.g., Insulin
Hydrophilic drugs which can not absorbed
(e.g. neomycin)
Drug interaction: One drug can affect the absorption
of other drug e.g., antacids decrease the absorption of
tetracycline.

6. Rapid onset of action
Useful in emergency- (glyceryl trinitrate, nifedipine &
ergotamine), especially if tablet is crushed, giving greater
surface area for solution
Effect can be terminated by spitting out tablet
No sterilization required, No skill needed
First pass hepatic metabolism Increase bioavailability
Not affected by gastric acidity or intestinal enzymes

7. Inconvenient for frequent use
Irritation of oral mucosa & excessive salivation
Promotes swallowing, so losing the advantage of by
passing the first pass effect
Patient compliance not ensured
Not suitable for large doses and vomiting patients
Bitter, irritant drugs cannot be given

8. Can be used for producing both the systemic effects
and local effects
Drugs that are irritant to stomach can be given by
suppository (aminophylline)
Suitable in unconscious, vomiting , motion sickness,
migraine or when a patient can not swallow, & when
cooperation is lacking (sedation in children)

9. Sterilization is not required
Minimal skill is required
Avoid 50% first pass hepatic metabolism (from
lower rectum)
For local effect e.g. in proctitis or colitis
Demerit-Psychological, patient may be embarrassed
Irritation of mucosa & inflammation may occur
with repeated use
Absorption unreliable, especially if rectum is full of
faeces

10. Rapid onset of action
Useful in emergency
No first pass effect, 100% bioavailability,
Dose more accurately delivered & give effective, &
Highly predictable blood concentration
Suitable in vomiting , motion sickness, migraine
Unconscious patients, or when a patient can not
swallow & when cooperation is lacking
Large volume (doses) of drug can be given

11. Costly, Inconvenient, Local irritation
More chances of adverse effects,
most dangerous
Maximal Sterilization, Skill is required
Self-medication is not advisable
Drugs that are too irritant
(anticancer agents) to be given
by other routes
Chances of local venous thrombosis
and infection with prolonged infusion

12. Reliable and suitable for irritant drugs and
depot preparations (penicillin, neuroleptics,
medroxyprogesterone) can be used at monthly
or longer intervals
Absorption is more rapid than subcutaneous injection
or oral route (soluble preparations are absorbed within
10 – 30 mins)

13. Demerits
Inconvenient
Painful especially for frequent use
More chances of adverse effects than oral route
Sterilization is required
Chances of infection are more
Skill required for administration
Local irritation at site of administration
Not acceptable for self administration
If any adverse effect occur that can not be
removed.

14. Can be used for local and systemic effects both
Reliable and acceptable for self administration
(e.g. diabetic patients taking Insulin)
For local effect --- e.g. local anesthetics
Poor absorption in peripheral circulatory failure
Repeated injections at one site can cause
lipodystrophy, resulting in erratic
absorption (insulin)

15. Small amount of drug can be given
Slow absorption
Tuberculin syringe
Example: BCG vaccine, diagnostic tests,
Allergic sensation testing

16. Site: Lumen of artery
Merits: Greater concentration of the drug can be
delivered
Demerits: Expertise and asepsis is required
Examples: Radiopaque contrast for coronary
angiography and cerebral angiography

17. Site: Subarachanoid space
Merits: Bypass blood brain barrier and blood CSF barrier-
acts directly on meninges and spinal cord
Demerits-Asepsis required, expertise is needed
Painful and Risky Eg: Radio-opaque contrast media,
Xylocaine inj, intrathecal injection of streptomycin in TB
Epidural-Through vertebral interspace between dura and
lining of spinal canal Eg: Xylocaine injection

18. Site: Tibial or Sternal bone marrow
The needle is introduced into marrow cavity and
effects are similar to those following intravenous
injection. This route is used when veins are not
available specially in children.
Merit: onset of action very fast
Demerits: Strict aseptic conditions,
Expertise and skill required
Painful and risky
Examples: Bone Marrow transplantation

19.  Site: Injection directly into the joint space
 Merit: High concentration is obtained in localized area
 Demerits: sepsis, Joint damage, Pain
 Examples: Hydrocortisone, Gold chloride for
rheumatoid arthritis
Intra Cardiac
In cardiac arrest intra-cardiac injection of
adrenaline is made for resuscitation.

20. Drugs directly into the nose.
Desmopressin is administered intranasally in the
Treatment of diabetes insipidus
Salmon calcitonin- osteoporosis
GnRH analogues

21. Site-Peritoneal space
The peritoneum offers a large absorbing surface area
from which drugs enter circulation rapidly but
primarily by way of portal vein. Hence First-Pass effect
not avoided.
Example: Dialyzing fluid-poisoning and renal failure
In lab animals
Merits-Rapid absorption-large surface area
Demerits-Painful, Risky, Adhesions, Peritonitis

22. Drugs as gases can be rapidly taken up or eliminated
Can be used for both local & systemic effects
Self administration is practicable
As gas General anaesthetics
As aerosolβ2 –adrenoceptor agonist bronchodilators
Aerosols & powders provide high local
concentration for action on bronchi, minimizing
systemic effects
Aerosols can also be used for systemic effect, e. g
ergotamine for migraine
As powder, e.g. sodium chromoglycate

23. Special apparatus is needed
Drug must be nonirritant.
If the patient is unconscious
Obstructed bronchi (mucus plugs in asthma) may
cause therapy to fail

24. Active ingredient is delivered across the
skin for systemic distribution.
Example: transdermal scopolamine, transdermal
nitroglycerine

25. Conjunctival, nasal and auditory
Eye drops, Ointment, nasal drops, nasal sprays
Isotonic aqueous solutions of drugs- sulfacetamide,
chloramphenicol, gentamycin
Atropine & β-adrenoceptor blocker to eye
Vaginal and urethral
Solutions, ointments, emulsions, foams, tablets,
suppositories and pessaries -Antifungal agents
Inunction and dermal
Rubbing the drug preparation on to the skin, dusting,
spraying

26. Merits
High local concentration can be used
without systemic effect
Demerit-Systemic effects can occur especially when
there is tissue destruction e.g., adrenal steroids
& neomycin to skin
Only small number of drugs can be used by
this route, Slow onset of action and local
reactions can occur

27. Intravenous 30-60 Seconds
Intraosseous 30-60 Seconds
Endotracheal 2-3 Minutes
Inhalation 2-3 Minutes
Sublingual 3-5 Minutes
Intramuscular 10-20 Minutes
Subcutaneous 15-30 Minutes
Rectal 5-30 Minutes
Ingestion 30-90 Minutes
Transdermal (Topical) Variable (Minutes To Hours)

28. “All substances are poisons;
there is none which is not a poison.
The right dose differentiates a poison from a remedy.”
Paracelsus (1493-1541)
THANKYOU
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