ANKI 1

This refers to the study of drugs

**Pharmacology**

What are the 3 stages of a Drug Action?

1. Pharmaceutic Phase
2. Pharmacokinetic Phase
3. Pharmacodynamic Phase

What phase of drug action deals with the process of dissolution of the drugs?

**Pharmaceutic phase**

What phase of drug action deals with the process of the movement of drugs inside the body?

**Pharmacokinetic Phase** 

What phase of drug action is the study of drug concentration and its effects to the body?

**Pharmacodynamic Phase** 

A tablet or capsule taken must become what to be able to cross the biological membrane?

Solution/liquid 

What form of drugs only undergo Pharmaceutic Phase?

Solid/Powdered drug

This is the pharmaceutic process of crushing the drug into small particles

Disintegration

This is the pharmaceutic process of turning the drug into liquid form

Dissolution

Between tablets and capsules, the dissolution happens faster with?

Capsules, since it is already in powdered form

Where do drugs travel through the bloodstream?

via the Plasma 

These are fillers and inert substances used in drug \n preparation to allow drugs to take on a particular size and shape and to enhance dissolution.

**Excipients** 

Are tablets 100% drugs?

No, they have excipients to help them dissolve quickly

What are the two common types of drug additives that help increase absorbability of a drug?

K & Na 

Most drugs are easily absorbed because of this acid found in the stomach

Gastric Acid

Some medicine are not easily absorbed by gastric acid like?

Penicillin (It needs a protein carrier such as K and Na to be absorbed by the cells) 

Do very young and very old people have higher gastric acidity?

False, they have less gastric acidity which is why lesser absorption capability. 

This is the time it takes the drug to disintegrate and dissolve to become available for the body to absorb

Rate limiting 

> Liquid drugs, of course, have faster rate limiting compared to solid drugs

This type of drugs resist disintegration in the gastric acid of the stomach, so disintegration is delayed until it reaches the alkaline environment of the small intestines.

Enteric-coated drugs 

> They remain in the stomach for a long time, meaning their effect is delayed. They can only be dissolved in an alkaline environment (small intestine)

What should you **never do to enteric-coated drugs**?

**Crush them**

> This is because crushing them will make them dissolved in the stomach which would negate its effect. It has to reach the small intestine to become effective

Why are some drugs need to be taken on an (1) empty stomach & on a (2) full stomach?

1. Empty stomach = better absorption
2. Full stomach = for less GI upset or distress

This is the **process of** __***drug movemen***__***t*** **to achieve** __*drug action*__

**Pharmacokinetic Phase** 

What are the 4 stages of the Pharmacokinetic Phase?

1. Absorption
2. Distribution
3. Metabolism/Biotransformation
4. Excretion 

Where does absorption take place?

In the **small intestine**, particularly by the ***mucosal villi*** 

What are the three movement of drug particles from GIT to body cells?

1. Passive Absorption
2. Active Absorption
3. Pinocytosis  

This type of movement is **governed by the principle of diffusion:** where the drug readily moves from area of higher concentration to area of lower concentration.

**Passive Absorption**

In this type of movement, **a protein carrier is needed for the drug to enter the cell.**

**Active absorption** 

In this type of movement, the **drug is engulfed by the cell**.

**Pinocytosis** 

Lipid-soluble drugs undergo what type of drug movement?

Passive absorption

> This is because cell membrane is made up of bi-lipid layers 

The type of **drugs that undergo active absorption** since they *need enzymes or protein transporters to enter the cell.*

**Water-soluble drugs**

Aspirin is an NSAID, antipyretic, and antiplatelet drug which is an example of a drug that undergoes what type of movement?

Passive absorption

> This is because it is considered a weak acid wherein in the bloodstream it travels with no charge so can easily pass through the cell membrane 

All aspirin comes in what form?

**Oral form** 

Aspirin is no longer given to children because it can lead to this syndrome that affects the liver and brain.

**Reye's syndrome** *(Acute hepatic encephalopathy)*

This refers to the **process by which most drugs pass through the liver first to be metabolized** before going into the bloodstream

**First-pass effect** 

Where does primary metabolism happen?

Liver 

T/F: Morphine and Warfarin are examples of First Pass Drugs.

TRUE

What are examples of High First-pass drugs that have no oral forms?

Lidocaine and some Nitroglycerines 

> Not recommended sa oral kasi mametabolize na totally bago pa makarating sa bloodstream. 

This refers to the percentage of administered drug that reaches systemic circulation

**Bioavailability**

T/F: Oral drugs' bioavailability is always LESS than 100%.

TRUE

**High-first pass drugs** like Lidocaine and some Nitroglycerines only have how many percent bioavailability?

**20-40% bioavailability** once it reaches the systemic circulation

The only drugs that have 100% bioavailability are those drugs that are given via what?

**IV Route (intravenous route)** 

> This is because the drug is given directly into the bloodstream

This is the process by which the drug becomes available to body fluids and body tissues

**Distribution** 

Distribution is influenced by what factors?

1. Protein-binding
2. Blood Flow
3. Body tissue affinity (it finds where its needed)

As drugs are distributed in the plasma many are bound to varying degrees with protein. What are the different categories of protein-binding abilities of drugs?

1. Highly protein bound > 89%
2. Moderately highly protein bound 61%
3. Moderately protein bound 30%
4. Low protein bound

What do you call the drugs that are not bound to protein and can cause a pharmacological response?

**Free drugs or active drugs** 

Explain the process of protein binding.

Ex. 

You have 100 mg Lidocaine. And lidocaine has 50% protein binding. So in the bloodstream ang aattach lang sa protein ay 50% so 50mg magiging reservoir for later use. Yung other 50mg become free drugs (And free drugs are active drugs). Active drugs are the ones that get absorbed. They cause the pharmacological response. Now as they get absorbed and excreted out of the body, yung other 50mg na naka-attach sa protein matatanggal tapos sila naman yung magiging free drug which gives the effect. 

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Protein-binding helps in the drug’s biological half-life (para mas tumagal yung effect nila at para hindi ma-overdose at mamaintain yung equilibrium)

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Protein binding can influence the drug's biological half-life. The bound portion may act as a reservoir or depot from which the drug is slowly released as the unbound form. Since the unbound form is being metabolized and/or excreted from the body, the bound fraction will be released in order to maintain equilibrium.

Why should you never give Piroxicam at the same time with Diazepam?

This is because both have high protein-binding abilities which can lead to toxicity or overdose of the patient. 

> Kapag binigay mo ng sabay yung Piroxicam and Diazepam - e parehong mataas yung protien-binding ability nila, mag-aagawan ngayon sila ng protein. Mangyayari is kukulangin yung protein so mas dadami yung free drugs na hindi naka-aattach sa protein. Dahil dumami yung free drugs na magcacause ng pharmacological effect, pwedeng ma-overdose yung patient. 

What are examples of Highly Protein-binding Drugs?

1. Piroxicam & Warfarin - 99%
2. Diazepam - 98%
3. Ibuprofen - 98%
4. Amitriptyline - 97&
5. Chlorpromazine, Dicloxacillin, Furosemide - 95%
6. Lorazepam, Propanolol, & Valproic acid - 92%

What is the usual site for metabolism?

In the GIT, specifically by the **liver** 

When the liver inactives a drug, it makes it a metabolite for what?

**Metabolite ready for excretion**

When the liver activates a drug, what does it do to the active metabolite?

It increases its pharmacological action

This refers to the chemical activity of our body when we take a drug

**Metabolism** or **Biotransformation**

This refers to the time it takes for one half of the drug concentration to be eliminated, and one half of the drug concentration to be absorbed.

**Half-life of a drug** 

This refers to the state by which the amount of a drug being absorbed is the same amount that's being excreted from the body when the drug is given continuously or repeatedly is called?

**Steady-state concentration** 

> It is the time during which the concentration of the drug in the body stays consistent.

What are the two factors that affect Half-life of a drug?

**Metabolism & Excretion**

What is the half-life of Aspirin?

3 Hours 

> Meaning, every 3 hours, the aspirin is reduced by half.  \n \n Thus, a 650 mg Aspirin will be used up in a span of 18 hours \n \n \n Q: How long will it take for 75% of 650 mg Aspirin to be \n eliminated from the body? \n Answer: 6 hours (look at percentage left)  \n

Which of the following has the highest drug half-life?


1. Digoxin
2. Aspirin
3. Ibuprofen
4. Phenytoin

1. Digoxin 

* Digoxin - 36H HL
* Aspirin - 3H HL
* Ibuprofen - 2H HL
* Phenytoin - 22H HL 

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> In terms of half-life, the percentage left in the body does not need to become 0%, 1% is enough. 

When the effect of the drug has been done, it is to be eliminated. The main route for elimination is through what?

**Kidneys**

What are the different routes of excretion?

1. Kidneys
2. Liver Metabolism
3. Bile
4. Feces
5. Lungs
6. Saliva
7. Sweat
8. Breastmilk

This is the study of drug concentration and its effects on the body

**Pharmacodynamic Phase**

Drug response can cause a?

Primary or Secondary Physiologic effection, or both

What is the primary and secondary effect of **Benadryl** or **Diphenhydramine**?

1. Primary effect = for allergic reactions
2. Secondary effect = drowsiness

This refers to the relationship between the minimal versus maximal amount of drug dose needed to produce desired drug response

**Dose Response**

> Ex. Lagundi Syrup Ascof, adult dose 5-10ml/1-2 teaspoon) Dose for children is different

This refers to the maximum drug effect

Maximal Efficacy 

> Ex. Morphine compared to Paracetamol – kahit gaano karami ang Paracetamol na itake mo, its dosages can never compare to a single dose of Morphine (na pinaka matapang sa lahat).

This is refers to the time it takes to reach minimum effective concentration after a drug is administered

**Onset** 

> Ex. When you take paracetamol and your temp starts to go down, onset na yun. (start of lowering temperature after fever)

This is when the drug reaches the highest blood of plasma concentration. 

**Peak** 

> This is when the drug is at its peak effectiveness because it's all in the bloodstream. 

Fastest drug to reach the peak are those given in?

**IV** 

How long does it take for drugs via IV to reach its peak of action?

**3-10 minutes**

How long does it take for drugs PO (via the oral route) to reach its peak of action?

**1-3 hours** 

This refers to the length of time which the drug has a pharmacologic effect

**Duration**

This refers to **drugs that produce a response**

**Agonists**

This refers to **drugs that block a response**

**Antagonists** 

Most **Agonist** and **antagonist** **drugs** are what type of drugs?

**Nervous system drugs that affects the brain**

An **agonist drug** that **stimulates the receptors** (alpha 1, beta 1, & beta 2) **of the brain** 

**Epinephrine** 

This is an antagonist drug that is a histamine blocker, resulting to the decrease of gastric acid secretion that can be used for patients with ulcer

**Cimetidine** 

The type of drugs that affect various body sites

**Nonspecific**

> Ex. A drug that affects the eyes, heart, lungs, GI tract

Bethanecol is an example of a non-specific drug that produces what kinds of cholinergic and parasympathetic effects?

1. Urinary bladder contraction (pampaihi)
2. Pupil constriction
3. Bronchioles constriction
4. Decrease in bp and hr
5. Increase in gastric acid

> This means that it does not only affect the urinary system, but also the other parts of the body. 

Which is an antipsychotic drug, used to treat psychotic disorders such as schizophrenia?

**Chlorpromazine/Thorazine**

Which has **more side effects, nonspecific or nonselective**?

**Nonselective drugs** 

What are the different categories of Drug action?

1. Stimulation or depression (Nervous System)
2. Replacement (Taking insulin for Diabetes)
3. Inhibition, Antimicrobial, Cytotoxic, or Killing of Organisms (Antibacterial, Antifungals)
4. Irritation (Constipation: can irritate the lining of GI tract to perform peristalsis.
5. Modification of Immune Status (Anti-inflammatory drugs)

This estimates the **margin of safety of a drug t**hrough the use of a ratio that measures the effective dose and the lethal dose. 

**Therapeutic Index** 

The type of drugs that has a narrow margin of safety

**Drugs with Low TI** *(Therapeutic Index)*

The type of drugs that has a wide margin of safety

**Drug with High TI** 

What are examples of Low TI Drugs?

1. Digoxin
2. Aminoglycosides (Amikacin, gentamicin, tobramycin) - antibiotics
3. MGSO4 - anticonvulsants 

This refers to the highest plasma concentration of a drug at a specific time which indicate rate of absorption

**Peak Drug Level**

This refers to the lowest plasma concentration of a drug which measures the rate at which a drug is eliminated

**Trough Drug Level**

The peak and trough drug levels must be taken when and in which type of drugs?

Immeditately before the next dose for Low TI drugs.

> This is to be able to monitor the range and prevent toxicity from occuring because high drug peak and through drug levels can lead to toxicity

This is the **large initial dose** given to achieve a rapid minimum effective concentration in the plasma when an immediate drug response is needed

**Loading dose** 

This drug is an example of a drug that can be given as **a loading dose to treat CHF** (congestive heart failure) in order to ***improve heart contraction and lessen congestion.***

**Digoxin** 

T/F: All loading dose are two-time dose.

False, All Loading Dose are one-time dose, then sinusundan lang ng maintenance dose (which is less dosage). This time the maintenance dose must have dose, route, and frequency.

> Ex.Digoxin 100mg IV now as LD, then 50mg Q8 IV for maintenance dose

This refers to the **common desirable and undesirable effects of the drug.**

**Side effects**

> Example: Benadryl (side effect is drowsiness)

* Taking a certain drug in the mornin while taking an exam, and got drowsy (undesirable)
* Taking a certain drug in the evening to have a good sleep (desirable)

These are the **undesirable effects of a drug** such as allergic reactions, superinfection, & organ toxicity

**Adverse reactions**

These are the **drug effects** that is considered ***dangerous*** and may be considered ***lethal***.

**Toxic Effects**

> Drugs with low TI; can cause neurotoxicity, autotoxicity, hepatotoxicity, and nephrotoxicity

This concepts deals with the **effect of a drug action that varies from a predicted drug response** because of genetic factors or hereditary influence (not effective for other race)

**Pharmacogenetics**

What are the two types of Antihypertensive ACE Inhibitors that are not effective to African-Americans & Caucasians?

**Captopril and Enalapril** 

This refers to the decreased responsiveness over the course of therapy.

Tolerance 

* Drug tolerance for narcotics can result in decrease pain relief
* Note: To avoid tolerance, drugs must be finished.
* Ex. Antibiotics must be finished for 7 days

This refers to the rapid decrease in response to the drug (Acute tolerance).

It describes an acute, sudden decrease in response to a drug after its administration.

Tachyphylaxis

> It can occur after an initial dose or after a series of small doses. Increasing the dose of the drug may be able to restore the original response

What are examples of drugs that can cause Tachyphylaxis?

1. Narcotics
2. Barbiturates
3. Anti-Anxiety
4. Laxatives
5. Antipsychotics

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> Most of Tachyphylactic drugs affect the Nervous System

This refers to the **psychologic benefit from a compound that may not have the chemical structure of a drug effect**. This is usually done in clinical drug studies. 

**Placebo Effect**

What are the 5 Traditional Rights of Drug Administration?

1. Right Client
2. Right Drug
3. Right Dose
4. Right Time
5. Right Route