PTCB PREP: SECTION 1 - MEDICATIONS

what is pharmacodynamics?

• study of how drugs cause their effects to happen

• usually by interacting w/ specific receptors found in cell membranes or intracellular fluid

what is an agonist?

the drug

what is an antagonist?

other drugs competing to bind at the same receptor as a drug (agonist)

what is pharmacokinetics?

study of body processes that interact w/ drugs: absorption, distribution, metabolism, and excretion (ADME)

what do the ADME processes involve the movement of drugs across within the body?

cellular membranes

what is absorption?

drug’s movement from site of administration into the bloodstream

what 3 factors influence the rate of absorption?

• molecule size

• lipophilicity (lipid/fat-loving)

• pH environment

what is distribution?

drug’s movement throughout body to reach their target sites

what is 1 factor that influences distribution?

tissue perfusion rates (rate of blood flow to tissues)

ex: highly perfused tissues → receive higher proportion of drug

what is metabolism/biotransformation?

• body transforms drugs into hydrophilic forms/water-soluble metabolites to eliminate them

• drug is transformed bcuz its considered a foreign substance (xenobiotics) → cannot be eliminated in this form

what is phase 1 metabolism?

drugs transformed thru oxidation, reduction, and hydrolysis

what is phase 2 metabolism?

combining drug/its metabolites w/ polar groups to allow for excretion

what is excretion?

elimination of drug from body:

• hydrophilic metabolites exit thru urine/bile

• tears

• sweat

• breath

• saliva

which organ plays a primary role in drug metabolism?

the liver bcuz it has many different enzymes

what is metabolism that happens in the liver called?

hepatic metabolism

which organ plays a primary role in drug excretion?

kidney

what is excretion that happens in the kidney called?

renal excretion

what is a generic name of a drug?

its approved name

what is a brand name of a drug?

its name made by its manufacturing company

what is an over-the-counter (OTC) drug?

• nonprescription drug (doesnt need a prescription)

• for relief of common symptoms

what are 2 categories of supplement drugs?

• water-soluble vitamins

• fat-soluble vitamins

what are water-soluble vitamins?

• vitamins that dissolve in water & arent retained in the body

• needs:

  • energy production

  • nerve function

  • strong immune system

• vitamin B, C

what are fat-soluble vitamins?

• vitamins that accumulate/build-up in fat tissues & liver

• for:

  • vision

  • bone health

  • antioxidant protection

  • blood clotting

• vitamins A, D, E, K

what are the requirements for a drug to be pharmaceutically equivalent?

• same active ingredient

• same dosage form

• same route of administration

• same strength/concentration

what are the requirements for a drug to be bioequivalent?

• no known/potential bioequivalence issues

• follows in vitro standard/bioequivalence standard

what are the requirements for a drug to be therapeutically equivalent?

• pharmaceutical equivalent

• bioequivalent

what 3 things are benzodiazepines for?

• anxiety disorders

• seizure disorders

• insomnia

what are the 2 suffixes for benzodiazepines?

• pam

• lam

what 3 things are barbiturates prescribed as?

• sedatives

• hypnotics

• anticonvulsants

what is the suffix for barbiturates?

barbital

what 2 things are amphetamines for?

• ADHD

• narcolepsy

what 2 things are methylphenidate for?

• ADHD

• narcolepsy

what 3 things are selective-serotonin reuptake inhibitors for?

• depression

• anxiety disorders

• obsessive-compulsive disorder (OCD)

what 2 things are tricyclic antidepressants (TCAs) for?

• depression

• chronic pain

what 2 things are monoamine oxidase inhibitors (MAOIs) for?

• depression

• certain anxiety disorders

what are typical antipsychotics for?

psychotic disorders like schizophrenia

what 2 things are atypical antipsychotics for?

• schizophrenia

• bipolar disorder

what are buspirones for?

generalized anxiety disorder

what 2 things are sodium channel blockers for?

• epilepsy

• seizure disorders

what 3 things are GABAergic drugs for?

• epilepsy

• neuropathic pain

• mood disorders

what 2 things are nonsteroidal anti-inflammatory drugs (NSAIDs) for?

• mild to moderate pain

• inflammatory conditions

what are the 3 suffixes for NSAIDs?

• profen

• proxen

• fenac

what are opioids for?

moderate to severe pain

what 3 things are ACE inhibitors for?

• hypertension

• heart failure

• diabetic nephropathy

what is the suffix for ACE inhibitors?

pril

what 3 things are angiotensin II receptor antagonists/blockers for?

• hypertension

• heart failure

• diabetic nephropathy

what is the suffix for angiotensin II receptor antagonists/blockers?

sartan

what 4 things are beta blockers for?

• hypertension

• angina (chest pain)

• arrhythmias (irregular heart rhythms)

• heart failure

what is the suffix for beta blockers?

olol

what 3 things are calcium channel blockers for?

• hypertension

• angina

• arrhythmias

what are the 3 types of drug-drug interactions?

• synergism:

  • when 2 drugs w/ similar effects are taken together

  • results in additive/enhanced responses

• antagonism

  • when 1 drug interferes w/ the actions of another drug

  • results in decrease in effectiveness

• potentiation

  • when 1 drug increases the effects of another drug

what is bioavailability?

fraction of a drug that enters the bloodstream &is available for action @ its target site

what are 3 types of drug-food interactions?

• decreased absorption:

  • when a food binds to a drug

  • results in decreased absorption of drug

• altered metabolism:

  • when a food affects drug-metabolizing enzymes

  • results in changes in drug concentrations

• impaired effectiveness:

  • when a food affects a drug’s therapeutic effects

what should be regularly monitored if a patient is taking warfarin?

international normalized ratio (INR) - how long it takes for blood to clot. makes sure blood isnt too thin or thick (either is dangerous)

what are the side effects of taking statins & grapefruit juice?

• muscle pain

• aches

what are the side effects of taking antiplatelet drugs, NSAIDs, and anticoagulant drugs individually/combined?

increased risk of bleeding

what are the side effects of taking multivalent ions (milk, antacids, calcium, magnesium, and iron) and various drugs like levothyroxine, tetracyclines, fluoroquinolones, and bisphosphonates?

decreased efficacy/effectiveness of drug

what are the side effects of taking nitrates and PDE5 inhibitors (ex: sildenafil & tadalafil)?

severe hypotension

what are the side effects of taking ACE inhibitors and potassium-elevating drugs (ex: trimethoprim or potassium supplements)?

increases likelihood of hyperkaliemia (high potassium levels)

what are the side effects of taking ritonavir & protease inhbitors?

alters metabolism of protease inhibitors

what are the side effects of taking beta blockers & calcium channel blockers?

increases risk of heart failure & bradycardia (reduced heart rate)

what are the side effects of taking broad spectrum antibiotics (ex: penicillin & cephalosporins) and warfarin?

increases risk of bleeding

what are the side effects of taking loop diuretics (ex: furosemide) & thiazide diuretics?

increases likelihood of digoxin toxicity

what are the side effects of taking aminoglycosides (ex: gentamicin & amikacin) & loop diuretics?

increases likelihood of ototoxicity (damage to inner ear) & kidney damage

what is the enteral route?

administering med thru gastrointestinal tract, which is then absorbed into bloodstream thru lining of stomach/intestines

what are 3 reasons why enteral route is the most commonly used route of administration?

• convenient

• safe

• cost-effective for both outpatient & inpatient care

what are 5 types of enteral routes?

• oral route

• sublingual route

• buccal route

• rectal route

• vaginal route

what are 4 limitations of oral route?

• potentially low bioavailability

• first-pass metabolism in liver (First Pass Effect)

• irritation to gastric mucosa

• slower onset of action

what is First Pass Effect?

• common for oral route

• when med is first metabolized in liver (reducing concentration in systemic circulation → affecting its effects)

  • med should pass liver & enter systemic circulation (system of all blood & vessels)

what is sublingual route?

1. place med under tongue

2. med absorbed thru buccal mucous membrane

3. med enters systemic circulation

what is the benefit of sublingual route?

quicker onset of action

what is buccal route?

1. place med between gums & inner cheek

2. med absorbed thru buccal mucosa

3. med enters systemic circulation

what are common dosage forms for buccal route?

• buccal tablets

• chewing gum

what are common dosage forms for rectal route?

• suppositories

• pessaries

what is rectal route?

1. insert med into rectum

2. med absorbed thru rectum

what is the benefit of rectal route?

alternative to oral route for those who are unconscious, have nausea, or have difficulty swallowing

what are 7 common dosage forms for vaginal route?

• solutions

• tablets

• creams

• gels

• suppositories

• rings

• pessaries

what is vaginal route commonly used for?

hormone replacement therapy in women during their menopausal period

what is local route?

administering med directly onto a specific area (doesnt really enter systemic circulation)

what is topical route?

applying med directly onto skin or mucous membranes

what are 5 common dosage forms for topical route?

• suspensions

• ointments

• jellies

• drops

• sprays

what is otic/ear route?

applying med into/thru ear

what is ocular/eye route?

applying med into eye

what are the 4 types of local route?

• topical route

• otic/ear route

• ocular/eye route

• inhalation

what is parenteral route?

administering med directly into system circulation without passing thru gastrointestinal tract

what are the 2 classes of parenteral route?

• injections

  • intravascular

  • intramuscular

  • subcutaneous

• without injections

  • inhalations

what are the benefits of parenteral route?

• faster onset of action

• suitable for emergency situations

• precise control over drug plasma concentration

what are cons of parenteral route?

• requires aseptic technique + trained ppl

• may cause pain/local tissue injuries

what is intravenous route (IV)?

delivers med directly into vein thru injections or infusions

what are the benefits of IV route?

• immediate onset of action

• precise control over drug concentration

• suitable for unconscious patients

what are the risks of IV route?

risks of:

• infections

• allergic reactions

• phlebitis (inflammation of vein)

what is intramuscular route (IM)?

delivers med directly into specific muscles

what are the benefits of IM route?

• uses depot/sustained-release formulations → good for treating chronic diseases

• no First-Pass Metabolism

• easier to administer than IV route

what are the disadvantages of IM route?

• may cause pain/discomfort

• alters absorption of drug depending on muscle group and blood flow to muscle

what is subcutaneous route (SC)?

delivering med into subcutaneous tissue thru direct infusion or injection

what is the benefit of SC route?

lower likelihood of systemic circulation infection compared to other routes

why should a fine needle be used for SC injection administration?

absorption of drug can vary depending on blood flow to SC tissue

what is intradermal route (ID)?

delivering med into dermis

what is ID route commonly used for?

performing skin tests for allergies or tuberculosis screening

what is the benefit of ID route?

faster absorption of med due to dermis’ rich supply of blood vessels (may cause unintended effects if med is intended for local action only instead of systemic circulation action)