The nature of drugs, drug development and regulation (Katzung, Ch 1. Trans 1-2, wkbk)

Question 1

Deals with the absorption, distribution, and elimination of drugs

Answer 1

Pharmacokinetics

Question 2

Concerns the actions of the chemical on the organism

Answer 2

Pharmacodynamics

Question 3

True or False

All substances can under certain circumstances be toxic

Answer 3

True

Question 4

True or False
The chemicals in botanicals (herbs and plant extracts, “nutraceuticals”) are different from chemicals in manufactured drugs because there is much greater proportion of impurities in manufactured drugs

Answer 4

False

** There is much greater proportion of impurities in botanical drugs

Question 5

REMEMBER

The molecular size of drugs varies from very small (lithium ion, MW 7) to very large (eg, alteplase [t-PA], a protein of MW 59,050). However, most drugs have molecular weights between 100 and 1000.

Answer 5

The lower limit of this narrow range is probably set by the requirements for specificity of action. The upper limit in molecular weight is determined primarily by the requirement that drugs must be able to move within the body. Drugs much larger than MW 1000 do not diffuse readily between compartments of the body.

**In the case of alteplase, a clot-dissolving enzyme, the drug is administered directly into the vascular compartment by intravenous or intra-arterial infusion.

Question 6

Three major types of drug-receptor bonds

Answer 6

Covalent, electrostatic and hydrophobic

Question 7

This type of drug-receptor bond is very strong and in many cases not reversible under biologic conditions

Answer 7

Covalent bond

Example:

1. Covalent bond formed between the acetyl group of acetylsalicylic acid (aspirin) and cyclooxygenase, its enzyme target in platelets, is not readily broken
2. DNA alkylating agents used in cancer chemotherapy to disrupt cell division in the tumor

Question 8

True or false

Electrostatic bonding is much more common than covalent bonding in drug-receptor interactions

Answer 8

True

• • Electrostatic bonds vary from relatively strong linkages between permanently charged ionic molecules to weaker hydrogen bonds and very weak induced dipole interactions such as van der Waals forces and similar phenomena.
• *Electrostatic bonds are weaker than covalent bonds

Question 9

This type of bond is important in the interactions of highly lipid-soluble drugs

Answer 9

Hydrophobic

Question 10

True or False
Drugs that bind through weak bonds to their receptors are generally more selective than drugs that bind by means of very strong bonds.

Answer 10

True
** This is because weak bonds require a very precise fit of the drug to its receptor if an interaction is to occur. Only a few receptor types are likely to provide such a precise fit for a particular drug structure

Question 11

In the Ra conformation (active form), a receptor can activate downstream mechanisms that produce a small observable effect, even in the absence of drug. This is termed as_______

Answer 11

Constitutive activity

Question 12

REMEMBER
The receptor is able to assume two conformations. In the Ri conformation, it is inactive and produces no effect, even when combined with a drug molecule. In the Ra conformation, the receptor can activate downstream mechanisms that produce a small observable effect, even in the absence of drug (constitutive activity).

Answer 12

In the absence of drugs, the two isoforms are in equilibrium, and the Ri form is favored.

Question 13

REMEMBER
The receptor is able to assume two conformations. In the Ri conformation, it is inactive and produces no effect, even when combined with a drug molecule. In the Ra conformation, the receptor can activate downstream mechanisms that produce a small observable effect, even in the absence of drug (constitutive activity).

Answer 13

Conventional full agonist drugs have a much higher affinity for the Ra conformation and mass action thus favors the formation of the Ra–D complex with a much larger observed effect.

Question 14

REMEMBER
The receptor is able to assume two conformations. In the Ri conformation, it is inactive and produces no effect, even when combined with a drug molecule. In the Ra conformation, the receptor can activate downstream mechanisms that produce a small observable effect, even in the absence of drug (constitutive activity).

Answer 14

Partial agonists have an intermediate affinity for both Ri and Ra forms. Conventional antagonists, according to this hypothesis, have equal affinity for both receptor forms and maintain the same level of constitutive activity.

Question 15

REMEMBER
The receptor is able to assume two conformations. In the Ri conformation, it is inactive and produces no effect, even when combined with a drug molecule. In the Ra conformation, the receptor can activate downstream mechanisms that produce a small observable effect, even in the absence of drug (constitutive activity).

Answer 15

Inverse agonists, have a much higher affinity for the Ri form, reduce constitutive activity, and may produce a contrasting physiologic result.

Question 16

Binding of a drug to a nonregulatory molecule such as plasma albumin will result in no detectable change in the function of the biologic system, so this endogenous molecule can be called _____

Answer 16

Inert binding site
** Such binding is not completely without significance, however, because it affects the distribution of drug within the body and determines the amount of free drug in the circulation. Both of these factors are of pharmacokinetic importance

Question 17

A weak acid is best defined as a neutral molecule that can reversibly dissociate into an anion (a negatively charged molecule) and a proton (a hydrogen ion)

Answer 17

A weak base can be defined as a neutral molecule that can form a cation (a positively charged molecule) by combining with a proton

Question 18

REMEMBER
The protonated form of a weak acid is the neutral, more lipid-soluble form, whereas the unprotonated form of a weak base is the neutral form

Answer 18

Inspection confirms that the lower the pH relative to the pKa, the greater will be the fraction of drug in the protonated form. Because the uncharged form is the more lipid-soluble, more of a weak acid will be in the lipid soluble form at acid pH, whereas more of a basic drug will be in the lipid-soluble form at alkaline pH

Question 19

REMEMBER
Almost all drugs are filtered at the glomerulus. If a drug is in a lipid-soluble form during its passage down the renal tubule, a significant fraction will be reabsorbed by simple passive diffusion

Answer 19

If the goal is to accelerate excretion of the drug (eg, in a case of drug overdose), it is important to prevent its reabsorption from the tubule. This can often be accomplished by adjusting urine pH to make certain that most of the drug is in the ionized state. Thus, weak acids are usually excreted faster in alkaline urine; weak bases are usually excreted faster in acidic urine

Question 20

An inactive precursor chemical that is readily absorbed and distributed which must be converted to the active drug by biologic processes inside the body

Answer 20

Prodrug

Question 21

For a drug given orally to produce an effect in the central nervous system, it must pass through barriers that include the tissues that make up the wall of the intestine, the walls of the capillaries that perfuse the gut, and the blood-brain barrier, the walls of the capillaries that perfuse the brain

Answer 21

Therefore drugs that enter the CNS must be lipid-soluble

Question 22

Aqueous diffusion of drug molecules is usually driven by the concentration gradient of the permeating drug, a downhill movement described by Fick’s law. Drug molecules that are bound to large plasma proteins (eg, albumin) do not permeate most vascular aqueous pores.

Answer 22

If the drug is charged, its flux is also influenced by electrical fields (eg, the membrane potential and—in parts of the nephron—the transtubular potential)

Question 23

This property of drug determines how readily the molecule moves between aqueous and lipid media

Answer 23

Lipid-aqueous partition coefficient

• *In the case of weak acids and weak bases (which gain or lose electrical charge-bearing protons, depending on the pH), the ability to move from aqueous to lipid or vice versa varies with the pH of the medium, because charged molecules attract water molecules.
• *The ratio of lipid-soluble form to water-soluble form for a weak acid or weak base is expressed by the Henderson-Hasselbalch equation

Question 24

Before clinical testing:

(1) Identification or elucidation of a new drug target
(2) Rational design of a new molecule based on an understanding of biologic mechanisms and drug receptor structure
(3) Screening for biologic activity of large numbers of natural products, banks of previously discovered chemical entities, or large libraries of peptides, nucleic acids, and other organic molecules

Answer 24

**Steps (1) and (2) are often carried out in academic research laboratories

Question 25

This phase of drug development involves a variety of assays at the molecular, cellular, organ system, and whole animal levels to define the pharmacologic profile, i.e., the activity and selectivity of the drug. The type and number of initial screening tests depend on the pharmacologic and therapeutic goal

Answer 25

Preclinical trial – drug screening **The desired result of this screening procedure (which may have to be repeated several times with congeners of the original molecule) is a lead compound

Question 26

In this phase of CLINICAL TRIAL, the effects of the drug as a function of dosage are established in a small number (20–100) of healthy volunteers. If the drug is expected to have significant toxicity, as may be the case in cancer and AIDS therapy, volunteer patients with the disease participate rather than normal volunteers

Answer 26

Phase 1

Question 27

REMEMBER Phase 1 trials are done to determine the probable limits of the safe clinical dosage range. These trials may be nonblind or “open”; that is, both the investigators and the subjects know what is being given.

Answer 27

Alternatively, they may be “blinded” and placebo controlled. Pharmacokinetic measurements of absorption, half-life, and metabolism are often done. Phase 1 studies are usually performed in research centers by specially trained clinical pharmacologists

Question 28

In this phase of CLINICAL TRIAL, the drug is studied in patients with the target disease to determine its efficacy (“proof of concept”), and the doses to be used in any follow-on trials. A modest number of patients (100–200) are studied in detail. A single-blind design may be used, with an inert placebo medication and an established active drug (positive control) in addition to the investigational agent.

Answer 28

Phase 2 **Phase 2 trials are usually done in special clinical centers (eg, university hospitals). Phase 2 trials have the highest rate of drug failures, and only 25% of innovative drugs move on to phase 3

Question 29

In this phase of CLINICAL TRIAL, the drug is evaluated in much larger numbers of patients with the target disease usually thousands to further establish and confirm safety and efficacy.

Answer 29

Phase 3 **Using information gathered in phases 1 and 2, phase 3 trials are designed to minimize errors caused by placebo effects, variable course of the disease, etc. Therefore, double-blind and crossover techniques are often used. Phase 3 trials are usually performed in settings similar to those anticipated for the ultimate use of the drug.

Question 30

This phase constitutes monitoring the safety of the new drug under actual conditions of use in large numbers of patients

Answer 30

Phase 4

Question 31

Philippine FDA-registered herbal medicines Lagundi – Vitex negundo L; used as an anti-histaminic (anti-asthmatic, expectorant and anti-inflammatory) Sambong – Blumea balsamifera; used in urinary tract pain and burning, to increase urinary output in edema, or as a preparation before laser treatment of kidney or bladder stones Akapulko – Cassia alata L; used as an antifungal, anti-lice and; anti-scabies

Answer 31

Tsaang gubat – Carmona retusa (Vahl) Masam; used in acute diarrhea, biliary colic and; gastric/intestinal colic from acute gastroenteritis Yerba buena – Menthacordifolia opiz; used in the symptomatic relief of mild to moderate pain secondary to circumcision, episiotomy, skin biopsy and; dental extractions

Question 32

Cardinal Concepts in Pharmacology

Answer 32

1. No drug can create a new effect 2. At most a drug can modulate intrinsic physiologic function 3. Can potentially alter the rate at which a bodily function proceeds

Question 33

Refers to the percentage of an active drug in a drug product that enters the systemic circulation at a certain rate

Answer 33

Bioavailability

Question 34

It is a measure of whether the bioavailability (BA) of a certain drug product is closely similar to the BA of the indicator drug

Answer 34

Bioequivalence

Question 35

Sources of drugs

Answer 35

1. plant sources 2. animal sources 3. microbes 4. Earth/soil 5. human sources

Question 36

PLANT SOURCES

Answer 36

a. Alkaloids b. Glycosides c. Oils d. Gum e. Resin: rosin-like substance usually formed by the oxidation of volatile oils; most are used as cathartics (pine rosin) f. Tannins: complex principle found widely distributed in plants; has astringent action and is used in the treatment of burns, diarrhea and hemorrhoids (tannic acid)

Question 37

PLANT SOURCES Alkaloids – basic organic substances containing carbon, hydrogen, nitrogen, and oxygen; occurs in almost all parts of plants but are most often found in seeds, roots and leaves

Answer 37

```  Atropine [anti-muscarinic]  Vinblastine  Vincristine [anti-cancer]  Quinine [anti-malaria]  Quinidine  Reserpine  Scopolamine  Cocaine  Ephedrine  Caffeine  Colchicine [anti-gout]  Morphine [analgesia]  Theophylline [treatment for asthma]  Theobromine ```

Question 38

PLANT SOURCES | Glycosides – ether-like combinations of sugar with some other organic substances

Answer 38

```  Digoxin [for congestive heart failure]  Digitoxin  Coumarin [anticoagulant]  Salicin [anti-inflammatory]  Hesperidin  Rutin  Quercetin ```

Question 39

``` PLANT SOURCES Oils 1. Volatile oil: evaporates readily without leaving a stain o Peppermint [anti-septic] o Oil of thyme o Spearmint o Oil of winter green ```

Answer 39

2. Fixed oil: greasy substance that leaves a stain o Castor [laxative] o Olive oil

Question 40

PLANT SOURCES Gum – secretory products from plants; carbohydrates that absorbs water and swell to form thick mucilaginous colloid solutions [used as external agent]

Answer 40

 Gum acacia |  Emulsifying agents

Question 41

``` Drugs from plant sources and their uses LEAF PLANT: DRUG: USE: ```

Answer 41

``` Drugs from plant sources and their uses LEAF PLANT: Digitalis DRUG: Digoxin USE: CHF ```

Question 42

``` Drugs from plant sources and their uses BARK PLANT: DRUG: USE: ```

Answer 42

``` Drugs from plant sources and their uses BARK PLANT: Cinchona DRUG: Quinine USE: Malaria ```

Question 43

``` Drugs from plant sources and their uses FRUIT PLANT: DRUG: USE: ```

Answer 43

``` Drugs from plant sources and their uses FRUIT PLANT: Opium poppy DRUG: Morphine USE: Analgesic ```

Question 44

``` Drugs from plant sources and their uses SEED PLANT: DRUG: USE: ```

Answer 44

``` Drugs from plant sources and their uses SEED PLANT: Calabar bean DRUG: Eserine/physostigmine USE: Glaucoma ```

Question 45

ANIMAL SOURCES

Answer 45

 Insulin  Protamine [antagonist of heparin]  Thyroid

Question 46

``` Drugs from animal sources and their uses COW ORGAN: DRUG: USE: ```

Answer 46

``` Drugs from animal sources and their uses COW ORGAN: Pancreas DRUG: Insulin USE: DM ```

Question 47

``` Drugs from animal sources and their uses FISH ORGAN: DRUG: USE: ```

Answer 47

``` Drugs from animal sources and their uses FISH ORGAN: Sperm DRUG: Protamine USE: Neutralize heparin effect ```

Question 48

``` Drugs from animal sources and their uses PIG ORGAN: DRUG: USE: ```

Answer 48

``` Drugs from animal sources and their uses PIG ORGAN: Intestine DRUG: Heparin USE: Anticoagulant ```

Question 49

``` Drugs from animal sources and their uses OX ORGAN: DRUG: USE: ```

Answer 49

``` Drugs from animal sources and their uses OX ORGAN: Thyroid DRUG: Dessicated thyroid USE: Hypothyroidism ```

Question 50

Sources of drugs | MICROBES

Answer 50

```  Penicillium  Beta-lactam  Gentamicin  Streptomyces  Bacitracin ```

Question 51

Drugs from microbes and their uses | SOURCE:ANTIBIOTIC:USE

Answer 51

PENICILLIUM: Penicillin: Broad spectrum; Gm + CEPHALOSPORIUM: Cefalexin: Broad spectrum; Gm + MICROMONOSPORA: Gentamicin: Gm - STRETOMYCES VENEZUELACE: Chloramphenicol: Broad spectrum STREPTOMYCES GRISEUS: Streptomycin: TB BACILLUS SUBTILIS: Bacitracin: Gm +

Question 52

Drugs from minerals and their uses | MINERAL:USE

Answer 52

IRON (Ferrous sulfate): Iron deficiency anemia SODIUM (Sodium chloride): Dehydration; electrolyte imbalance IODINE (Potassium iodide): Endemic goiter MAGNESIUM (Magnesium sulfate): Purgative; tocolytic BICARBONATE (Sodium bicarbonate): Antacid ALUMINUM (Aluminum hydroxide): Antacid

Question 53

Drugs from human sources and their uses. | MEDICATION:USE

Answer 53

HUMAN CHORIONIC GONADOTROPIN: Tumor marker; infertility REGULAR INSULIN: DM UROKINASE: Thrombolytic agent

Question 54

``` SYNTHETIC DRUG - There is no need for a natural source - Pure chemical substances produced in the laboratory, made by emulating or imitating substances found in nature. Advantages: 1. Better quality control 2. Process is easy and cheap 3. More potent and safer alternatives 4. Large scale production Examples: 1. Co-trimoxazole 2. Diphenoxylate 3. Meperidine 4. Ofloxacin ```

Answer 54

``` SEMI-SYNTHETIC DRUG - A natural chemical compound is modified in the laboratory - Examples:  Morphine: hydrocodone  Penicillin: amoxicillin  Caphalosporin C: cefalexin  Salicin: aspirin ```

Question 55

Things to consider when manufacturing a drug for commercial use:

Answer 55

o Stability - Drug should be stable (temperature, pH, wont disintegrate immediately, etc) o Shelf life - Higher shelf-life, lower price (since the need for production won’t be immediate) o Pharmacokinetic factors - Influence of the body to the drug o Patient factors: - Child: ex. how to initiate administration of the drug - Liquid drops (infants) - Suspension (children) - Capsule (mainly for adults)

Question 56

EXCIPIENTS FUNCTIONS

Answer 56

1. To maintain stability 2. To prolong shelf life 3. In consideration of pharmacokinetic factors 4. Addressing patient factors

Question 57

EXCIPIENTS FUNCTIONS: | To maintain stability

Answer 57

1. Fillers  Add volume; usually inert (no reaction when mixed with the pharmacologic ingredient)  Should be compatible with other components; cheap  Tasteless or pleasant taste 2. Binders  Keep ingredients in a tablet together (especially in solids/tablets)  Ensure that tablets and granules can be formed with required mechanical strength, and gives volume to low active dose tablets (e.g. saccharides, sorbitol, gelatin, PEG) 3. Lubricants  Prevents ingredients from clumping together and sticking to the tablet punches or capsule filling machine 4. Sorbents  Used for tablet or capsule moisture-proofing by limited fluid sorbing in a dry state

Question 58

REMEMBER | Role of a lubricant:

Answer 58

True lubricant role: o Decrease friction at the interface between a tablet’s surface and the die wall during ejection and reduce wear on punches and diesAnti-adherent role: o Prevent sticking to punch faces or in the case of encapsulation, lubricants. Prevents sticking to machine dosators, tamping pins Glident role: o Enhance product flow by reducing interparticulate friction

Question 59

EXCIPIENTS FUNCTIONS: | To prolong shelf life

Answer 59

1. Preservatives  Vitamins A, C, E, selenium, cysteine, methionine, citric acid, Na citrate 2. Coating agent  Serve to protect tablets from destruction in the environment, heat from the sun; (e.g. HMPC, hydropropylcellulose, and methylcellulose) 3. Humectant  Attracts and retain moisture drawing water vapor and reduce rate of moisture loss (e.g. calcium chloride, sodium lactate, glycerin, mannitol, sorbitol, PEG)

Question 60

EXCIPIENTS FUNCTIONS: | In consideration of pharmacokinetic factors

Answer 60

1. Coating agent 2. Solvent 3. Buffer agents 4. Surfactants 5. Disintegrants

Question 61

EXCIPIENTS FUNCTIONS: | Addressing patient factors

Answer 61

1. Colors  Easy identification of medication  Adds to the identification of the tablet  In children, it appeals to the attractiveness  Viagra is blue (“the blue pill”) 2. Flavors/sweetness  Bitter: mint/cherry  Salty: peach, apricot  Sour: raspberry  Pinoy flavors: banana (like pedialight), dalandan

Question 62

``` Solid dosage requirements: o Should not have difficulty in swallowing o Old enough to swallow o Conscious o No abnormalities in GIT o Drug can be absorbed in the GIT ```

Answer 62

Different Solid Preparations: 1. Tablets 2. Capsules 3. Lozenges or Pastilles 4. Plaster 5. Pills 6. Spansules - Capsule containing granules with coating to slowly disintegrate the drug

Question 63

Different Solid Preparations: Tablets  Granulated or powdered drugs which are compressed or molded into round, discoid, or ovoid shapes

Answer 63

a. Uncoated tablet b. Multilayered tablet c. Scored tablet d. Coated tablets e. Sustained release tablets f. Suppository

Question 64

Different Solid Preparations: | Tablets - Uncoated tablet

Answer 64

```  Fast dissolution  Compressed tablet like Biogesic, aspirin  Sublingual and buccal tablets  Effervescent tablets  It readily disintegrates in the mouth  Chewable tablets (e.g. Aspilets)  Lozenges, troches ```

Question 65

Different Solid Preparations: | Tablets - Multilayered tablet

Answer 65

 Ex.: Alaxan, which contains paracetamol and ibuprofen

Question 66

Different Solid Preparations: | Tablets - Scored tablet

Answer 66

 Example: Tablets for hypertensive patients.  Scores used for dividing  Must have good storage to avoid oxidation; oxidation lessens the efficacy of the drug.

Question 67

Different Solid Preparations: | Tablets - Coated tablets

Answer 67

 Enteric, sugar coated; also called a caplet  Example: Viagra  Cannot be divided because oxidation reaction and other reactions can affect the drug.  Sugar coating to cover drugs’ bitter taste

Question 68

Different Solid Preparations: Tablets Sustained release tablets  Ensure compliance, i.e. take in once a day rather than thrice a day

Answer 68

Suppository  Tablets inserted in cavities  Mixture of substances with a firm base suitable for insertion into body cavities  Disintegrates in a fast rate Ex. vaginal suppository - makes use of a dispenser; rectal suppository **Rectal route acts faster than the oral route since it doesn’t pass through the first part of metabolism

Question 69

Different Solid Preparations: Capsules  Soluble container made of tasteless gelatin containing powdered or liquid drugs

Answer 69

a. Hard shell capsule  Contains solids like powder or granules  When a capsule is taken only once a day it most likely contains granules b. Soft shell capsules  Contains active ingredient mixed with oil  Example: Vit. E and omega 3

Question 70

Advantages and disadvantages of tablets: ADVANTAGES 1. Can make the drug more palatable; address taste and odor concerns 2. May contain larger amounts of ingredients (more than 500mg) 3. Easy product identification 4. Can make the drug more palatable; address taste and odor concerns 5. Can house multiple ingredients (eg. Alaxan) 6. Can make numerous sustained release preparations 7. For large scale production 8. Can prolong shelf life

Answer 70

DISADVANTAGES 1. Hard to swallow (large tablets) 2. Some drugs have poor solubility 3. Need a machine to produce large quantities 4. Needs multiple excipients 5. Some drugs resist compression

Question 71

HARD SHELL CAPSULES - ADVANTAGES 1. Rapid drug release 2. Comes in all shapes 3. Easy to manufacture 4. Good oxygen barriers - DISADVANTAGES 1. Slow filling equipment 2. Sticks together 3. Made out of bones of animals (chitosan)

Answer 71

SOFT SHEL CAPSULES - ADVANTAGES 1. Easy to swallow 2. Comes in all shapes 3. Taken in various ways 4. Tamper resistant - DISADVANTAGES 1. Costly 2. Sticks together 3. Made out of skin of pigs

Question 72

``` LIQUID DOSAGE Different liquid preparations 1. Aqueous solutions a. solution b. aromatic water c. syrup d. douche e. enemas f. gargles g. nasala solution h. mucilage i. decoction j. infusion ```

Answer 72

2. alcoholic preparations a. elixir b. spirit of essence c. tincture 3. Emulsion 4. Suspension a. Mixture/oral suspension b. magmas and milk c lotion 5. extractives a. tincture b. extract c. fluid extract

Question 73

Different liquid preparations: Solution  homogenous liquid prepared by dissolving a solid, liquid, or gas in water o Strong iodine solution o Saturated solution of potassium iodide

Answer 73

Different liquid preparations: Infusion  less active ingredient than extracts;  obtained by extracting the active principle of a substance by using cold or hot water

Question 74

Different liquid preparations: Decoction  obtained by boiling medicinal herbs in water  has more of the active ingredient than infusions, but less than extracts

Answer 74

Different liquid preparations: Gargles  for cleansing;  used for treating the pharynx and nasopharynx by forcing in from the lungs through the gargle which is held in the throat

Question 75

Different liquid preparations: Douche |  for cleansing part of a body cavity

Answer 75

Different liquid preparations: Enema  preparation done prior to colonoscopy/surgery  rectal injections employed to evacuate the bowel

Question 76

Different liquid preparations: Spirits |  alcoholic or hydroalcoholic solutions of volatile substances

Answer 76

Different liquid preparations:Emulsion  Two immiscible liquids in which one liquid is dispersed in the form of small droplets throughout another liquid  ex. Vitamins are Oil in water emulsion

Question 77

Different liquid preparations: Suspension  Won’t dissolve into homogenous solution;  preparations of finely divided drugs suspended in water by means of agents  Will need to hake to ensure equal doses of active ingredients

Answer 77

Different liquid preparations:Extracts |  a lot of the active ingredient since it is more concentrated

Question 78

Different liquid preparations: Syrups  heavily mixed with sugars;  concentrated solution of sugar in water

Answer 78

Different liquid preparations: Elixir  also heavily mixed with sugars  hydroalcoholic solution intended for oral use  eg benadryl

Question 79

Advatages and disadvantages of liquid forms - ADVANTAGES 1. Easy to swallow 2. Faster absorption 3. Flexibility in proper dosing, i.e. ability to adjust dosage 4. Faster dissolution rate

Answer 79

- DISADVANTAGES 1. Shorter shelf life 2. Difficult to administer 3. Might need special storage 4. Harder to measure

Question 80

SEMISOLID DOSAGE Properties o Smooth texture o Homogenous o Non-dehydrating, non-greasy, non-staining, non-irritating o Do not alter membrane function: Some topical agents can dry up the skin and cause breaks due to some of the ingredients o Miscible with skin secretions o Can easily be applied with efficient drug release o High aqueous washability

Answer 80

``` Role of Semi-solids o Emollient - Sooths the skin, prevents dehydration without evaporation of the ingredients, with good moisturizing quality o Occlusive - Applied to burned areas to protect the exposed dermal tissues, muscles, and bones o Lubrication - True with topical eye gels o Application of active ingredient ```

Question 81

Different forms of semi-solids

Answer 81

1. Ointment 2. Cream 3. Paste 4. Gel

Question 82

Different forms of semi-solids: Ointment

Answer 82

 Homogenous, translucent, viscous semi-solid greasy preparation applied to the skin or the mucous membrane  Main function is to apply the active ingredient (drug delivery)  Secondary role s to sooth the surface and maintains hydration  Most of the topical antibiotics are in the ointment form Ex.: Teramycin to the wound

Question 83

Different forms of semi-solids: Cream |  Viscous, opaque emulsion

Answer 83

Consistency depends on emulsion:  Water in oil: lipophilic material and moisturizes and hydrates skin (ex. Moisturizers); good as emollient and cleansing agent  Oil in water: hydrophilic form and good for drug delivery (ex. Antibiotics); does not easily attract dirt

Question 84

Different forms of semi-solids: Paste

Answer 84

 Contains high percentage of insoluble solids, are therefore highly concentrated  Ointment-like preparation consisting of an absorptive powder dispersed in petrolatum; used in treatment of oozing lesions  Less greasy, good adhesion to the skin  For drug delivery Ex: zinc oxide

Question 85

Different forms of semi-solids:Gel

Answer 85

 Hydro-alcoholic polymeric matrix with high degree of chemical and physical cross-linking  Semisolid homogenous preparation in which a substance is distributed uniformly throughout the liquid  Hydrated Forms of soluble drugs are in gel form  Main function is to lubricate and maintain hydration

Question 86

PARENTERAL DOSAGE  Drugs that are being used for injection or infusion into the blood stream, through the use of syringe and needle  Routes: IV, IM, SQ

Answer 86

Different forms of parenterals: 1. Ampule - Contains liquid, in a form of aqueous solution 2. Vial - Solid form inside, need a solvent

Question 87

DRUGS FOR INHALATION Inhaler  Powder, granule, solutions, emulsion or suspensions in a mixture held under pressure in a dispenser  Salbutamol for asthma

Answer 87

Nebulizer  Device used to administer medication in the airways through vapour formed from the release of air or oxygen from the machine into the cavity where there is the liquid form of the drug, which is then inhaled by the patient

Question 88

Dangerous drugs

Answer 88

1. Prohibited drugs | 2. Regulated drugs

Question 89

Dangerous drugs: Prohibited drugs

Answer 89

1. Narcotic drugs - drugs that relieve pain, induce sleep and produce withdrawal symptoms when stopped after chronic administration; e.g. opium, morphine, heroine, codeine, meperdine and methadone 2. Stimulants - produce mental and physical stimulation, euphoria and self-satisfaction; e.g. cocaine, alpha and beta eucaine 3. Hallucinogens - provoke alterations of time and space perception, illusions and delusions; e.g marijuana, LSD, mescaline

Question 90

Dangerous drugs: Regulated drugs

Answer 90

- include self-inducing sedatives, such as secobarbital, phenobarbital and any drug which contains a salt or a derivative of a salt of barbituric acid; any salt, isomer or salt of an isomer of amphetamine; and hypnotic drugs

Question 91

DANGEROUS DRUG PREPARATIONS (DDP): SPECIFIC PRESCRIPTION REQUIREMENTS Per DDB Regulation No, 3 s. 2003 - to be prescribed thru DOH Official Rx Form, 1 DDP per Rx, partial filling allowed, No Refill

Answer 91

``` A. Buprenorphine (Norspan patch) B. Codeine as poly styrene divinyl benzene sulfonate (Codipront N Capsule; Codipront N Syrup) C. Diazepam (Ampul: anxiol, diazepam, lorcam, trankil, valuim) D. Ephedrine sulfate E. Fentanyl F. Fentanyl citrate G. Hydromorphone Hydrochloride (jurnista tablet) H. Methylphenidate I. Midazolam J. Morphine Sulfate K. Oxycodone Hydrochloride L. Pethidine Hydrochloride M. Phenobarbital sodium N. Pentobarbital sodiun ```

Question 92

DANGEROUS DRUG PREPARATIONS (DDP): SPECIFIC PRESCRIPTION REQUIREMENTS Per DDB Regulation No, 3 s. 2005 - to be prescribed thru Ordinary Rx with S2, 1 DDP per Rx, partial filling allowed, No Refill

Answer 92

Ketamine ( vial: ketamax, ketozol, ketram)

Question 93

DANGEROUS DRUG PREPARATIONS (DDP): SPECIFIC PRESCRIPTION REQUIREMENTS Per DDB Regulation No, 4 s. 2005 - preparation not in injectable form i.e. capsule, tablet or syrup, to be prescribed thru Ordinary Rx with S2, 1 DDP per Rx, partial filling allowed, No Refill

Answer 93

A. Pseudoephidrine Hydrochloride | B. Pseudoephidrine Sulfate

Question 94

DANGEROUS DRUG PREPARATIONS (DDP): SPECIFIC PRESCRIPTION REQUIREMENTS Per DDB Regulation No, 8 s. 2004 - preparation not in injectable form i.e. capsule, tablet or syrup, to be prescribed thru Ordinary Rx with S2, 1 DDP per Rx, partial filling allowed, No Refill

Answer 94

``` A. Diazepam B. Bromazepam C. Clonazepam D. Chlorazepate dipotassium E. Estazolam G. Flurazepam H. Mazindol I. Midazolam J. Nitrazepam K. Phenobarbital sodium L. Phentermine Resin M. Zolpidem ```

Question 95

``` Selected latin abbreviations and meanings Abbreviation:derivation:meaning ac: ante cebum: before meals bid: bis in die: 2x a day g: gramma: gram gr: granum: grain gtt: gutta: a drop h: hora: hour hs: hora somni: at bedtime non rep: non repetatur: not to be repeated pc: post cebum: after meals prn: pre re nata: when needed qh or q1h: quaque hora: every hour qid: quator in die: 4x a day qs: quantum sufficit: sufficient quantity Sig or S: signa: laberl stat: statum: immediately tid: ter in die: 3x a day ```

Answer 95

``` Metric doses and apothecary equivalents Metric: appox apothecary equiv 30 ml: 1 fluid ounce 60 mg: 1 grain 30 g: 1 ounce ``` ``` Approximate equiv of household measures 1 drop: 1/20 ml: 1 minim 1 teaspoonful: 8 ml: 1 dram 1 tablespoon: 15 ml: 1/2 fluid ounce 1 glassful: 250 ml: 8 fluid ounces ```