Routes of Drug Administration

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Questions and Answers

What is the maximum dose for non-aqueous preparations when administering fluids via oral gavage?

5 ml/kg

20 ml/kg

10 ml/kg (correct)

15 ml/kg

Which route of administration bypasses the first-pass effect?

Sublingual (correct)

Intramuscular (IM)

Rectal

Intravenous (IV)

What is the advantage of sublingual administration?

Rapid onset of action

Can be used for all types of drugs

Bypasses destruction by stomach acid (correct)

High bioavailability

What is the limitation of sublingual administration?

Limited to certain types of drugs Signup and view all the answers

Why is rectal administration ideal?

Ideal if the drug causes vomiting Signup and view all the answers

What is the advantage of parenteral administration?

All of the above Signup and view all the answers

What is the limitation of rectal administration?

Drugs may irritate the rectal mucosa Signup and view all the answers

What is the bioavailability of parenteral administration?

Essentially 100% Signup and view all the answers

What is the primary advantage of the oral route of drug administration?

Easy, safe, and convenient Signup and view all the answers

What is the main disadvantage of the oral route of drug administration in uncooperative or unconscious patients?

Unsuitability of the route Signup and view all the answers

What type of capsule is manufactured in two pieces?

Hard gelatin capsule Signup and view all the answers

What is the purpose of slow-release preparations in oral drug administration?

To extend the duration of action by protecting them from digestive enzymes Signup and view all the answers

What is the main difference between sublingual and buccal routes of drug administration?

Sublingual route is used for systemic action, while buccal route is used for local action Signup and view all the answers

What is the primary advantage of chewable tablets over regular tablets?

They can be chewed before swallowing Signup and view all the answers

What is a disadvantage of topical administration?

It can cause direct irritation of the meninges. Signup and view all the answers

Which of the following is NOT a characteristic of a drug suitable for transdermal administration?

It requires rapid administration. Signup and view all the answers

What is a factor that affects the selection of a suitable route of administration?

The physio-chemical properties of the drug. Signup and view all the answers

What is an advantage of transdermal administration?

It bypasses the first-pass effect. Signup and view all the answers

Why may some drugs not be suitable for transdermal administration?

They are not lipophilic. Signup and view all the answers

What is an advantage of the intravenous route of administration?

Can have immediate effects Signup and view all the answers

What is a disadvantage of transdermal patches?

They can cause delayed delivery of the drug to the site of action. Signup and view all the answers

Which route of administration is ideal for gases?

Inhalation Signup and view all the answers

What is a disadvantage of the subcutaneous route of administration?

Pain or necrosis if the drug is irritating Signup and view all the answers

What is an advantage of the intrathecal/intraventricular route of administration?

Drugs can bypass the blood-brain barrier Signup and view all the answers

What is a disadvantage of the inhalation route of administration?

Systemic absorption may occur, which is not always desirable Signup and view all the answers

Which of the following is a characteristic of depot preparations administered subcutaneously?

Slow and sustained absorption Signup and view all the answers

What is an advantage of the intranasal route of administration?

Rapid onset of action because the nasal cavity is well vascularized Signup and view all the answers

What is a disadvantage of the intranasal route of administration?

Limited volume can be sprayed into the nasal cavity Signup and view all the answers

Study Notes

Enteral Route

Enteral route involves administration of drugs through the gastrointestinal tract
Includes oral, sublingual, buccal, and rectal routes

Oral Route

Most common and convenient route of administration
Advantages: easy, safe, economical, and preferred by patients
Disadvantages: limited absorption, affected by food, unsuitable for uncooperative or unconscious patients, and first-pass effect
Solid dosage forms:
- Tablets: hard-compressed units consisting of active ingredients and excipients
- Chewable tablets: can be chewed before swallowing
- Capsules: gelatin containers filled with medication (hard gelatin and soft gelatin)

Sublingual/Buccal Route

Absorption pattern depends on physico-chemical properties of drugs
Advantages: bypasses first-pass effect, bypasses stomach acid, and immediate pharmacological effects
Disadvantages: limited to certain types of drugs, limited to small doses, and may lose part of the drug dose if swallowed

Rectal Route

Partially bypasses first-pass effect, bypasses stomach acid, and ideal for drugs that cause vomiting
Advantages: suitable for unconscious patients, bypasses digestive enzymes, and ideal for high-molecular-weight proteins and peptide drugs
Disadvantages: may irritate rectal mucosa and not a well-accepted route

Parenteral Route

Includes intravenous, intramuscular, and subcutaneous routes
Injections act rapidly, with 100% bioavailability, and can be used for drugs that are poorly absorbed or ineffective when given orally

Intravenous (IV) Route

Advantages: immediate effects, ideal for large volumes, suitable for irritating substances, and valuable in emergency situations
Disadvantages: unsuitable for oily or poorly absorbed substances, bolus injection may result in adverse effects, and strict aseptic techniques needed

Subcutaneous (SC) Route

Depends on drug diluents: aqueous solutions for prompt absorption and depot preparations for slow and sustained absorption
Advantages: suitable for slow-release drugs and ideal for poorly soluble suspensions
Disadvantages: pain or necrosis if drug is irritating and unsuitable for large volumes

Other Routes

Inhalation route:
- Advantages: rapid absorption, ideal for gases, effective for patients with respiratory problems, and fewer systemic side effects
- Disadvantages: systemic absorption may occur, addictive, and patients may have difficulty regulating dose
Intranasal route:
- Advantages: rapid onset of action, bypasses first-pass metabolism, and suitable for local and systemic effects
- Disadvantages: limited volume, continuous and frequent administration may irritate nasal epithelium
Intrathecal/Intraventricular route:
- Advantages: drugs can bypass blood-brain barrier, local effects, and fewer systemic side effects
- Disadvantages: can cause direct irritation of meninges
Topical route:
- Advantages: easy, non-invasive, and local effect
- Disadvantages: most drugs have high molecular weight, poorly lipid-soluble, and very slow absorption
Transdermal route:
- Advantages: slow and sustained, bypasses first-pass effect, convenient, and painless
- Disadvantages: some patients are allergic to patches, drug must be highly lipophilic, and may cause delayed delivery of drug to site of action

Selection of Suitable Route of Administration

Depends on:
- Physio-chemical properties of the drug (solubility, stability, pH, irritation)
- Site of desired drug action (local, systemic)
- Rapidity of desired response (fast or slow response)
- Rate and extent of absorption from different routes
- Effect of digestive juices and first-pass metabolism
- State of patient (conscious, vomiting)

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Description

This quiz covers the different routes of drug administration, including enteral, parenteral, and topical routes, and their advantages and disadvantages.