Pharmacology Practice Flashcards

A set of 100 flashcards based on lecture notes covering Oxybutynin, Scopolamine, prescription writing, pharmacokinetics, pharmacodynamics, and specific drug classes like NSAIDs and gout treatments.

What are the primary therapeutic effects of Oxybutynin?

Reduces urgency, decreases urinary frequency, and treats overactive bladder.

What are the expected antimuscarinic effects in Oxybutynin toxicity?

Dry mouth, flushed skin, confusion, blurred vision, tachycardia, and urinary retention.

Which cardiovascular symptom is an exception to the expected tachycardia in Oxybutynin toxicity?

Bradycardia.

What is the mnemonic for anticholinergic toxicity?

Hot as a hare, Dry as a bone, Red as a beet, Blind as a bat, Mad as a hatter.

What are the common adverse effects of Scopolamine?

Dry mouth, blurred vision, mydriasis, sedation, and drowsiness.

What does the acronym ESSC stand for in prescription writing?

Efficacy, Safety, Suitability, and Cost.

What information must be included in the 'Patient Information' section of a prescription?

Name, Age/Sex, Address (if required), and Date.

In prescription writing, what is the 'Superscription'?

The symbol Rx.

What components make up the 'Inscription' of a prescription?

Drug name, dosage form, and strength.

What is the 'Subscription' in a prescription?

The quantity to dispense.

What five elements should be included in the 'Signa' (Label) section?

Dose, route, frequency, duration, and special instructions.

What information is required under 'Prescriber Information'?

Name, signature, PRC License Number, PTR Number, and Address/City.

Why is Paracetamol the best choice for a patient with fever and a history of GI bleeding or hemorrhagic stroke?

It is an effective analgesic/antipyretic with minimal GI toxicity, no platelet inhibition, and is the safest option for peptic ulcer disease history.

Historically, why was Physostigmine used for glaucoma?

Because it is a tertiary amine capable of ocular penetration.

What is the primary clinical use for Scopolamine (Hyoscine)?

Motion sickness prevention.

Which drug is more commonly used for intestinal spasm than Scopolamine?

Dicyclomine.

Why is Physostigmine avoided in suspected tricyclic antidepressant (TCA) overdose?

It may precipitate serious cardiac arrhythmias or seizures.

What is the preferred treatment for TCA toxicity?

Supportive care and sodium bicarbonate.

According to the Philippine Generics Act, how should a drug name be prescribed?

Always prescribe the generic name unless a specific brand is clinically justified.

What does 'OD' represent in ophthalmic abbreviations?

oculus dexter (right eye).

What does 'OS' represent in ophthalmic abbreviations?

oculus sinister (left eye).

What does 'OU' represent in ophthalmic abbreviations?

oculus uterque (both eyes).

What does 'AD' represent in otic abbreviations?

auris dextra (right ear).

What does 'AS' represent in otic abbreviations?

auris sinistra (left ear).

What does 'AU' represent in otic abbreviations?

auris utraque (both ears).

What is defined as the chemical component responsible for the intended pharmacologic effect?

The active ingredient.

What is the 'Generic name' of a drug?

The recognized nonproprietary name of the active drug substance.

How is a 'Chemical name' defined?

It describes the drug's precise chemical structure or composition.

What is the volume of 1 teaspoonful?

$5\,mL$.

What is the volume of 1 tablespoonful?

$15\,mL$.

What is the approximate volume of 1 dessertspoonful?

$8-10\,mL$.

What is the volume of 1 ordinary glass?

$240-250\,mL$.

What is the rough approximation of drops in $1\,mL$?

$20\text{ drops}$.

From which source is Lanolin derived?

Wool-bearing animals, particularly sheep.

What is an elixir?

A clear, sweetened, flavored, hydroalcoholic oral liquid preparation.

What is the purpose of alcohol in an elixir?

It helps dissolve ingredients that are poorly soluble in water.

What is a 'Suspension'?

Insoluble solid particles dispersed in a liquid vehicle.

What is a 'Douche'?

A solution used to cleanse or irrigate a body cavity.

How do lozenges or troches act?

They dissolve slowly in the mouth, commonly for local throat or oral effects.

What are two characteristics of rectal suppositories regarding administration to specific patients?

They can be administered to vomiting, unconscious, or uncooperative patients.

What happens to a rectal suppository after insertion?

It melts, dissolves, or disperses.

Do rectal suppositories undergo first-pass metabolism?

They may partially bypass hepatic first-pass metabolism.

What is the primary goal of extended-release preparations?

To maintain therapeutic concentrations for a longer period and reduce dosing frequency.

Can extended-release tablets be crushed?

They should generally not be crushed, split, or chewed unless specifically permitted.

What are common disadvantages of parenteral administration?

More invasive, more expensive, requires trained personnel, and risks infection or tissue injury.

Which specific route of administration provides exactly $100\%$ bioavailability?

Intravenous.

Why is the inhalational route often very rapid?

Because of the large pulmonary surface area.

Between rectal, sublingual, inhalational, and intramuscular, which is likely the slowest?

Rectal administration.

What are the advantages of topical preparations?

High local drug concentration, reduced systemic exposure, and fewer systemic adverse effects.

What are radiopharmaceuticals used for?

Diagnostic imaging, functional studies, and targeted therapy.

What is a 'Prototype Drug'?

A representative drug used to illustrate the important characteristics of a pharmacologic class.

How does Activated Charcoal work?

Through physical adsorption by binding drugs and toxins to its extensive surface.

Name four substances for which Activated Charcoal is ineffective.

Caustic acids, alkalis, alcohols, iron, lithium, and some hydrocarbons.

Which form of a drug crosses lipid membranes more readily?

The non-ionized, lipid-soluble form.

What factors determine the ionization of a drug?

Drug $pKa$ and environmental $pH$.

What are four examples of weak noncovalent drug-receptor bonds?

Hydrogen bonds, ionic interactions, van der Waals forces, and hydrophobic interactions.

What is the characteristic of covalent drug-receptor bonds?

They are strong and usually produce prolonged or irreversible receptor binding.

What is 'Counterfeit Incorporation'?

When an abnormal molecule resembles a normal cellular constituent and is incorporated into a biologic pathway, impairing its function.

Define Pharmacokinetics.

What the body does to the drug (Absorption, Distribution, Metabolism, Excretion).

Define Pharmacodynamics.

What the drug does to the body (Receptor interaction, biochemical and physiologic effects).

What is Bioavailability?

The fraction of an administered dose that reaches the systemic circulation unchanged.

Why is the small intestine a major site of drug absorption?

Large surface area, rich blood supply, long contact area, and the presence of villi and microvilli.

What does the Area Under the Curve (AUC) represent?

Total systemic drug exposure.

How does high plasma protein binding affect drug distribution?

Drugs remain predominantly within the vascular compartment and have a lower apparent volume of distribution.

What is the formula for Volume of Distribution ($V_d$)?

$V_d = \text{Amount of drug in the body} / \text{Plasma drug concentration}$.

What does a high Volume of Distribution suggest?

Extensive tissue distribution, tissue binding, and lipid sequestration.

What is the relationship formula between Volume of Distribution and half-life at constant clearance?

$t_{1/2} = 0.693 V_d / Cl$.

What are the consequences of drug storage in adipose tissue?

Adipose tissue acts as a reservoir, drug effects may be prolonged, and redistribution may terminate CNS effects.

What reactions are commonly included in Phase I metabolism?

Oxidation, reduction, and hydrolysis.

What is the result of Phase II metabolism reactions?

Increased polarity, increased water solubility, and facilitation of renal or biliary excretion.

Which Phase II glucuronide conjugate remains pharmacologically active?

Morphine-6-glucuronide.

What is a common consequence of a CYP450 inhibitor like Cimetidine?

Reduced metabolism of substrates, leading to increased plasma concentration and toxicity risk.

List four common CYP450 enzyme inducers.

Rifampicin, Phenytoin, Carbamazepine, and Phenobarbital.

What is first-order elimination?

A constant fraction of the drug is eliminated per unit time.

What is zero-order (capacity-limited) elimination?

A constant amount of the drug is eliminated per unit time because pathways are saturated.

Give three examples of drugs that undergo zero-order elimination.

Ethanol, Phenytoin, and high-dose aspirin.

What process occurs in the proximal tubule during renal excretion?

Active tubular secretion.

When are Phase IV clinical studies conducted?

After regulatory approval and marketing.

What is the definition of $EC_{50}$?

The concentration of a drug that produces $50\%$ of its maximal effect.

How is potency related to $EC_{50}$?

A lower $EC_{50}$ indicates greater potency.

What is 'Efficacy' in pharmacodynamics?

The maximum effect ($E_{max}$) a drug can produce.

What is the 'Therapeutic Index' (TI) formula used in animal studies?

$TI = LD_{50} / ED_{50}$.

Define Tachyphylaxis.

A rapidly developing reduction in response after repeated doses over a short period.

Which receptor family produces the fastest responses (in milliseconds)?

Ligand-gated ion channels.

Give two examples of ligand-gated ion channels.

Nicotinic acetylcholine receptor and $GABA_A$ receptor.

What is the largest major receptor family?

G-protein-coupled receptors (GPCRs).

Which receptor family does the insulin receptor belong to?

Enzyme-linked receptors (specifically receptor tyrosine kinases).

What is the mechanism of intracellular or nuclear receptors?

They regulate gene transcription and generally have a slower onset but prolonged effects.

What is the outcome of Nitric Oxide signaling in vascular smooth muscle?

Soluble guanylyl cyclase activation, increased cyclic GMP, and vasodilation.

Define 'Synergism' in drug interactions.

The combined effect is greater than the expected sum ($1+1 > 2$).

Define 'Potentiation' and provide an example.

A drug with no effect alone increases the effect of another drug ($0+1 > 1$); for example, Clavulanate potentiating Amoxicillin.

What is a 'P-drug'?

A prescriber’s preferred treatment for a condition, selected systematically based on ESSC.

What is an ‘inappropriate indication’?

When a medicine is prescribed for a condition it cannot appropriately treat, such as antibiotics for a viral cold.

What is a Type A (Augmented) adverse drug reaction?

A dose-related, predictable reaction related to the drug's known pharmacology.

What is a Type B (Bizarre) adverse drug reaction?

An unpredictable, usually non-dose-related, often immune-mediated reaction.

What is a Type E (End-of-Use) reaction?

A reaction occurring following withdrawal, such as rebound hypertension after clonidine withdrawal.

How do most conventional NSAIDs work?

They inhibit cyclooxygenase (COX) enzymes and reduce prostaglandin and thromboxane synthesis.

What are the characteristics of Paracetamol?

Primarily analgesic and antipyretic, minimal anti-inflammatory action, and does not significantly inhibit platelet function.

What is the limitation of selective COX-2 inhibitors like Celecoxib regarding cardiovascular health?

They may increase cardiovascular thrombotic risk by reducing endothelial prostacyclin while sparing platelet thromboxane.

What is the mechanism of action for Colchicine?

It binds tubulin and inhibits microtubule polymerization, reducing neutrophil migration.