Pharmacology: Absorption of Medications

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Questions and Answers

What type of transport does NOT require energy for the absorption of enteric coated medication?

Active transport

Endocytosis

Osmosis

Facilitated diffusion (correct)

Which of the following processes involves drug absorption by a cell engulfing drug particles?

Facilitated diffusion

Filtration

Pinocytosis (correct)

Diffusion

In which part of the body does absorption of enteric coated medication primarily take place?

Colon

Mucosal lining of the small intestine (correct)

Gallbladder

Stomach

Which statement about diffusion in drug absorption is true?

It does not require energy. Signup and view all the answers

Which of the following is NOT a method of absorption in the small intestine?

Exocytosis Signup and view all the answers

What is the primary aim of the Philippine National Drug Formulary?

To make quality essential drugs available Signup and view all the answers

Which herbal remedy is used to boost the immune system?

Astragalus Signup and view all the answers

What is a recognized benefit of Ginger according to the herbal remedies listed?

Reducing nausea and motion sickness Signup and view all the answers

What regulatory act aims to strengthen the capacity of the FDA in the Philippines?

Food and Drug Administration Act of 2009 Signup and view all the answers

Which herbal remedy is associated with treating bronchitis and gastrointestinal problems?

Cinnamon Signup and view all the answers

What does the expiration date of medication ensure?

Safety before administering the medication Signup and view all the answers

Which herb is known for its effect on managing cholesterol levels?

Garlic Signup and view all the answers

Which of the following is NOT mentioned as a use of Echinacea?

Chronic hepatitis Signup and view all the answers

What is the basic formula to determine the amount to administer?

Amount to administer = desired dose x vehicle Signup and view all the answers

According to Young’s Rule, how is a child’s dose calculated?

Child's Dose = age in years x average adult dose / (age in years + 12) Signup and view all the answers

How does Clark’s Rule determine a child's dose?

Child's Dose = weight of child in lbs x average adult dose / 150 Signup and view all the answers

What factor is used in Fried's Rule to determine an infant's dose?

Infant's age in months Signup and view all the answers

What does the formula Amount to administer = vehicle x desired dose / drug on hand help calculate?

Amount of drug to administer Signup and view all the answers

In the ratio problem, what are the extremes and means represented by?

Extreme: Drug on hand and vehicle; Mean: desired dose and x Signup and view all the answers

Which ratio method involves multiplying the drug on hand by x?

Cross multiplication Signup and view all the answers

When calculating a patient's dose based on body weight, what is the formula used?

Patient’s Dose = Drug Dose x Body Weight / 150 Signup and view all the answers

What is the primary reason for avoiding milk when taking iron supplements?

Milk hampers the absorption of iron. Signup and view all the answers

Which drug effect occurs when two drugs are combined and one blocks the effect of the other?

Antagonistic drug effect Signup and view all the answers

What is an example of a desirable additive drug effect?

Administering a diuretic with a beta blocker for hypertension. Signup and view all the answers

How does a synergistic drug effect differ from an additive drug effect?

Synergistic effects create a greater result than either drug alone. Signup and view all the answers

What is the focus of pharmacogenetics?

The genetic factors influencing drug efficacy. Signup and view all the answers

What does the placebo effect refer to?

A drug response not due to the drug's chemical properties. Signup and view all the answers

Which of the following is an example of a synergistic drug combination?

Amoxicillin with clavulanic acid. Signup and view all the answers

What does ethnopharmacology primarily focus on?

The use of herbs and animal products as healing remedies. Signup and view all the answers

In what situation would an antidote be administered?

To counteract a drug overdose. Signup and view all the answers

What is a common consequence of an adverse drug reaction?

Unwanted side effects from the medication. Signup and view all the answers

Which route of drug administration has a higher absorption rate due to increased blood flow?

Intramuscular Signup and view all the answers

What is the main consequence of the first-pass effect on orally administered drugs?

Metabolism to an inactive form Signup and view all the answers

What does bioavailability refer to?

The percentage of administered drug available for activity Signup and view all the answers

Which factors may affect the bioavailability of a drug?

Drug form and gastric mucosa Signup and view all the answers

What happens to highly protein-bound drugs in the bloodstream?

The unbound portion is inactive and cannot exert effects Signup and view all the answers

How does liver dysfunction affect drug bioavailability?

It may increase bioavailability if the drug is liver-metabolized Signup and view all the answers

What is the primary impact of a drug passing through the liver before reaching systemic circulation?

It reduces the amount of active drug available Signup and view all the answers

For orally administered drugs, which factor does NOT affect bioavailability?

Environmental exposure Signup and view all the answers

What type of drugs are considered weakly protein-bound?

Drugs that are less than 10 % bound to protein Signup and view all the answers

Which route provides drugs with 100% bioavailability?

Intravenous Signup and view all the answers

Study Notes

Absorption of Medications

Most medications are absorbed in the small intestine via passive diffusion, facilitated diffusion, and pinocytosis.
Passive diffusion involves the movement of a drug from an area of higher concentration to an area of lower concentration without requiring energy.
Facilitated diffusion relies on a carrier protein to move the drug across the cell membrane.
Pinocytosis involves cells engulfing drug particles into a vesicle and carrying them across the cell membrane.

Intramuscular (IM) Drug Absorption

IM medications are absorbed faster in muscles with increased blood flow, such as the deltoid, compared to muscles with lower blood flow, such as the gluteus maximus.

Subcutaneous Drug Absorption

Subcutaneous administration has a lower rate of absorption than IM administration due to decreased blood flow compared to muscle.

Bioavailability

Bioavailability refers to the percentage of an administered drug that is available for activity.
For orally administered drugs, bioavailability is influenced by absorption and first-pass metabolism.

First-Pass Metabolism

When oral drugs are absorbed from the GI tract, they pass through the portal vein to the liver before reaching systemic circulation.
In the liver, some drugs are metabolized to an inactive form and excreted, reducing the amount of drug available for systemic circulation.
This is known as the first-pass effect or first-pass metabolism.

Factors Affecting Bioavailability

Drug form: The form of the drug (e.g., tablet, liquid) can affect its bioavailability.
Route of administration: Different routes of administration (oral, IM, IV) can lead to varying bioavailability.
Gastric mucosa and motility: The condition of the stomach lining and its ability to move contents can influence absorption.
Administration with food and other drugs: Co-administration of food or other medications can impact drug absorption and bioavailability.
Changes in liver metabolism: Conditions like liver dysfunction or reduced hepatic blood flow can affect drug metabolism and bioavailability.

Protein Binding of Drugs

Many drugs bind to plasma proteins like albumin and lipoproteins.
Highly protein-bound drugs are more than 90% bound to protein, while weakly protein-bound drugs are less than 10% bound.
The portion of the drug bound to protein is inactive because it cannot interact with tissue receptors.
The unbound portion of the drug is free and active, able to exit the bloodstream and reach its site of action.

Drug Interactions

Additive drug effect: The combined effect of two drugs is greater than the sum of their individual effects. This can be desirable or undesirable.
Synergistic drug effect (potentiation): One drug enhances the effect of another drug, resulting in a combined effect greater than the sum of individual effects.
Antagonistic drug effect: One drug reduces or blocks the effect of another drug.

Pharmacogenetics

The study of how genetic factors influence an individual's response to specific drugs.

Placebo Effect

A drug response not attributed to the chemical properties of the drug, but rather to psychological factors.

Ethnopharmacology

Focuses on the use of herbs, powders, teas, and animal products as healing remedies in different cultures.

Commonly Used Herbal Remedies

Astragalus: Used to boost the immune system.
Chamomile: Used for sleeplessness, anxiety, and stomach/intestinal ailments.
Cinnamon: Used for bronchitis, gastrointestinal problems, anorexia, and diabetes.
Echinacea: Used for colds, flu, and infections.
Garlic: Used to lower cholesterol, blood pressure, and reduce heart disease.
Ginger: Used for nausea, motion sickness, and diarrhea.
Ginkgo: Used for asthma, bronchitis, fatigue, and tinnitus.
Ginseng: Used to boost the immune system, increase well-being, and increase stamina.
Hawthorn: Used for the treatment of heart diseases.
Licorice root: Used to treat stomach ulcers, bronchitis, sore throat, and viral hepatitis.
Milk thistle: Used for cirrhosis, chronic hepatitis, and gallbladder disorders.
Peppermint: Used for nausea, indigestion, irritable bowel syndrome, colds, headaches, muscle and nerve pain.

Philippine National Drug Formulary

Provides a list of essential drugs available in the Philippines.
Aims to make quality essential drugs available, accessible, efficacious, safe, and affordable.
Registered with FDA or Pharmacopoeia.

FDA (Food and Drug Administration)

Responsible for regulating food and drugs in the Philippines.
Established by RA#9711 (Food and Drug Administration Act of 2009).
Aims to strengthen and rationalize the regulatory capacity of the BFAD (Bureau of Food and Drugs).

Universally Accessible Cheaper and Quality Medicines Act of 2008 (RA#9502)
Policy of the state to protect public health by making cheaper and quality medicines accessible.

Drug Calculations

Basic Formula: Amount to administer = desired dose x vehicle / drug on hand.
Ratio & Proportion: Drug on hand : vehicle : : desired dose : x.
Dimensional Analysis: Amount to administer = vehicle x desired dose / Drug on hand x.
Young's Rule: Child's Dose = age in years x average adult dose / Child's age in years + 12.
Clark's Rule: Child's Dose = weight of child in lbs x average adult dose / 150.
Fried's Rule: Infant's Dose = Infant's age in months x average adult dose / 150 months.
Body Weight: Patient's Dose = Drug Dose x Body Weight.

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Description

This quiz explores the mechanisms of medication absorption, including passive diffusion, facilitated diffusion, and pinocytosis. It also covers the differences in absorption rates for intramuscular and subcutaneous drug delivery methods, along with the concept of bioavailability. Test your knowledge on how various factors influence drug absorption!