251 Pharmacology Study Cards - Up to Antiparkisonian Flashcards
What is an additive effect?
Drug interactions in which the effect of a combination of two or more drugs with similar actions, administered at the same time, is the action of one plus the action of the other, with the total effect of both drugs being given (compare with synergistic effects).
What is an adverse drug event?
Any undesirable occurrence as a result of administering or failing to administer a prescribed medication.
What is an adverse drug reaction?
Any unexpected, unintended, undesired, or excessive response to a medication given at therapeutic dosages
What is included in a drug profile?
- any and all drug use, including home or folk remedies and herbal or homeopathic treatments, plant or animal extracts, and dietary supplements;
- intake of alcohol, tobacco, and caffeine;
- current or past history of illegal drug use;
- use of over-the-counter medications;
- use of hormonal drugs;
- past and present health history and associated drug regimen(s);
- family history and ethnic or cultural attributes, with attention to different responses to medications;
- growth and developmental stage; and
- issues related to the patient’s age and medication regimen.
Define adverse effects.
A general term for any undesirable effects that are a direct response to one or more drugs.
Define agonist.
Drugs that bind to and stimulate the activity of one or more receptors in the body.
Define allergic reaction.
An immunological hypersensitivity reaction resulting from the unusual sensitivity of a patient to a medication; a type of adverse drug event.
Define antagonists.
Drugs that bind to and inhibit the activity of one or more receptors in the body; also called inhibitors.
What are antagonistic effects?
Drug interactions in which the effect of a combination of two or more drugs is less than the sum of the individual effects of the same drugs given alone; usually caused by an antagonizing (blocking or reducing) effect of one drug on another.
What is bioavailability?
A measure of the fraction of drug administered dose that is delivered unchanged to the systemic circulation (from 0% to 100%). Essentially it describes the degree of drug absorption.
What is biotransformation?
One or more biochemical reactions involving a parent drug.
What is the chemical name of a drug?
The name that describes the chemical composition and molecular structure of a drug.
What is a contraindication?
Any condition, especially one that is a result of a disease state or patient characteristic, including current or recent drug therapy, that renders a form of treatment improper or undesirable.
What is cytochrome P450?
The general name for a large class of enzymes that play a significant role in drug metabolism and drug interactions.
What does dependence mean?
A state in which there is a compulsive or chronic need, as for a drug.
Describe dissolution.
The process by which solid forms of drugs disintegrate in the gastrointestinal tract and become soluble before they are absorbed into the circulation.
Define drug.
Any chemical that affects the physiological processes of a living organism.
What are drug actions?
The processes involved in the interaction between a drug and body cells (e.g., the action of a drug on a receptor protein); also referred to as mechanisms of action.
Describe drug effects.
The physiological reactions of the body to a drug. They can be therapeutic or toxic and describe how the body is affected by the drug. The terms onset, peak, and duration are used to describe drug effects (most often referring to therapeutic effects).
What is it called when one drug in a class of several drugs is chosen as the preferred agent, even though the drugs do not have the same active ingredients.
Therapeutic equivalence.
What is drug-induced teratogenesis?
The development of congenital anomalies or defects in the developing fetus that are caused by the toxic effects of drugs.
What is a drug interaction?
Alteration of the pharmacological or pharmacokinetic activity of a given drug caused by the presence of one or more additional drugs; it is usually a result of effects on the enzymes required for metabolism of the involved drugs.
What is the duration of action?
The length of time the concentration of a drug in the blood or tissues is sufficient to elicit a therapeutic response.
Define enzymes.
Protein molecules that catalyze one or more of a variety of biochemical reactions, including those that are a result of the body’s physiological processes or drug metabolism.
Explain the first-pass effect.
The initial metabolism in the liver of a drug absorbed from the gastrointestinal tract before the drug reaches the systemic circulation through the bloodstream. Phenomenon of drug metabolism whereby the concentration of a drug, specifically when administered orally, is greatly reduced before it reaches the systemic circulation.
If a drug has a high or heavy first-pass effect, what does that mean?
It means that when a drug is taken orally, very little of the drug reaches systemic circulation.
What is the generic name of a drug?
The name given to a drug approved by Health Canada; also called the nonproprietary name or the official name. The generic name is much shorter and simpler than the chemical name and is not protected by trademark.
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
A hereditary condition in which red blood cells break down when the body is exposed to certain drugs.
Define half-life.
In pharmacokinetics, the time it takes for the blood level of a drug to be reduced by 50%; also called elimination half-life.
What is an idiosyncratic reaction?
An abnormal and unexpected response to a medication, other than an allergic reaction, that is peculiar to an individual patient.
What is meant by incompatibility?
The characteristic that causes two parenteral drugs or solutions to undergo a reaction when mixed or given together that results in the chemical deterioration of at least one of the drugs.
What is an intrathecal injection?
A route of drug injection through the theca of the spinal cord and into the subarachnoid space. This route is used to deliver certain chemotherapy medications to kill cancer cells in the central nervous system.
What is considered a medication error?
Any preventable adverse drug event involving inappropriate medication use by a patient or health care provider; may or may not cause patient harm.
What is the medication use process?
The prescribing, dispensing, and administering of medications and the monitoring of their effects.
What is a metabolite?
A chemical form of a drug that is the product of one or more biochemical (metabolic) reactions involving the parent drug. Active metabolites are those that have pharmacological activity of their own, even if the parent drug is inactive (see prodrug). Inactive metabolites lack pharmacological activity and are simply drug waste products awaiting excretion from the body (e.g., via the urinary, gastrointestinal, or respiratory tract).
Define the onset of action.
The time required for a drug to elicit a therapeutic response after dosing.
What is a parent drug?
The chemical form of a drug that is administered before it is metabolized by the body’s biochemical reactions into its active or inactive metabolites. A parent drug that is not pharmacologically active is called a prodrug. A prodrug is then metabolized to pharmacologically active metabolites.
Define peak effect.
The time required for a drug to reach its maximum therapeutic response in the body.
What is a peak level?
The maximum concentration of a drug in the body after administration, usually measured in a blood sample for therapeutic drug monitoring.
Define pharmaceutics.
The science of preparing and dispensing drugs, including dosage form design (e.g., tablets, capsules, injections, patches, etc.).
What are pharmacodynamics?
The study of what the drug does to the body. The study of the biochemical and physiological interactions of drugs at their sites of activity; it examines the properties of drugs and their pharmacological interactions with body protein receptors.
What is pharmacokinetics?
The study of drug absorption, distribution, metabolism, and excretion (ADME) of drugs.
What is a prodrug?
An inactive drug dosage form that is converted to an active metabolite by various biochemical reactions once it is inside the body.
What are the characteristics of the nursing process?
- A research-based organizational framework for professional nursing practice
- Flexible, adaptable, and considered the major systematic framework for professional nursing practice
- Ensures the delivery of thorough, individualized, and quality nursing care to patients
- Requires critical thinking (clinical reasoning and clinical judgement)
- Ongoing and constantly evolving process
What aspects are included in a medication profile?
Any and all drug use
Home or folk remedies; natural heath products or homeopathic treatments
Alcohol, tobacco, caffeine intake
Current or past illicit drug use
Prescriptions and over-the-counter medications
Past or present health history and associated drug regimen
Family history; growth and developmental stage
Issues related to age and medication regimen
Define adherence.
Active, voluntary, and collaborative involvement of the patient in the mutually acceptable, prescribed course of treatment or therapeutic plan.
Define prescriber.
Any health care provider licensed by the appropriate regulatory body to prescribe medications.
What are the 10 rights of medication administration?
Right drug (or Right Medication) Right dose Right time Right route Right patient Right reason Right documentation Right evaluation (or right assessment) Right patient education Right to refuse
What are time critical scheduled medications?
Facility-defined medications: Administer at exact time when necessary (e.g., rapid-acting insulin), otherwise within 30 minutes before or after scheduled time.
What are non-time critical scheduled medications?
Daily, weekly, monthly medications: Administer within 2 hours before or after scheduled time.
Medications prescribed more frequently than daily but no greater than q4h: Administer within 1 hour before or after scheduled time.
Which organ plays a large role in the metabolism of drugs?
The liver
Does a heavy or high first pass effect result in little or a lot of the drub making its way into systemic circulation?
A little; the liver metabolizes much of it in this case and bioavailability is low for systemic circulation.
True or false: bioavailability is always expressed as a percentage?
True
What is a synergistic effect?
Drug interactions in which the effect of a combination of two or more drugs with similar actions is greater than the sum of the individual effects of the same drugs given alone.
What is therapeutic drug monitoring?
Ongoing monitoring of plasma drug concentrations and dosage adjustment based on these values as well as on other laboratory indicators such as kidney and liver function tests; this monitoring is often carried out by a pharmacist in collaboration with medical, nursing, and laboratory staff. Looking to maximize therapeutic effect and minimize toxic effects.
What is a therapeutic effect?
The desired or intended effect of a particular medication.
Define therapeutic index.
Ratio between the toxic and therapeutic concentrations of a drug.
What is a thin-film drug delivery?
Drug products that dissolve in the mouth and are absorbed through the oral mucosa.
What is time-release technology?
A technique used in tablets and capsules such that drug molecules are released in the patient’s gastrointestinal tract over an extended period.
Define drug tolerance.
A progressively decreased responsiveness to a drug, resulting in a need for a larger dose of the drug to achieve the effect originally obtained by a smaller dose.
Define trough level.
The lowest concentration of a drug reached in the body after it falls from its peak level, usually measured in a blood sample for therapeutic drug monitoring.
Define diarrhea.
Abnormal passage of stools with increased frequency, fluidity, and weight or with increased stool water excretion
Consists of three or more loose or liquid stools per day
What are characteristics of acute diarrhea?
Sudden onset in a previously healthy person
Lasts from 3 days to 2 weeks
Self-limiting
Resolves without sequelae
What are characteristics of chronic diarrhea?
Lasts for more than 3 to 4 weeks
Associated with recurring passage of diarrheal stools, fever, loss of appetite, nausea, vomiting, weight loss, and chronic weakness
What are some causes of acute diarrhea?
Bacteria Viruses Drugs (drug induced) Nutritional factors Protozoa
What are some causes of chronic diarrhea?
Tumours Diabetes Addison's disease Hyperthyroidism Irritable bowel syndrome AIDS
What are the goals of diarrhea treatment?
Stopping the stool frequency
Alleviating the abdominal cramps
Replenishing fluids and electrolytes
Preventing weight loss and nutritional deficits from malabsorption
What are three kinds of antidiarrheal drugs?
Adsorbents Antimotility drugs (anticholinergics and opiates) Probiotics (also known as intestinal flora modifiers and bacterial replacement drugs)
What is the mechanism of action of adsorbents on diarrhea?
- Coats the walls of the gastrointestinal tract
- Binds to the causative bacteria or toxin, which is then eliminated through the stool
What is one example of an adsorbent?
- bismuth subsalicylate (Pepto-Bismol®)
What kind of drug is bismuth subsalicylate an example of?
An adsorbent
What is the mechanism of action of antimotility drugs that fall into the anticholinergic category?
- Decrease intestinal muscle tone and peristalsis of gastrointestinal tract Result: slows the movement of fecal matter through the gastrointestinal tract
- Slows peristalsis by reducing the rhythmic contractions and smooth muscle tone of the gastrointestinal tract
- Have a drying effect
- Reduce gastric secretions
- Used in combination with adsorbents and opiates
What is the mechanism of action of antimotility drugs that fall into the opiate category?
Decrease bowel motility and reduce pain by relief of rectal spasms
Decrease transit time through the bowel, allowing more time for water and electrolytes to be absorbed
What are three examples of antimotility opiate drugs?
- codeine phosphate
- loperamide hydrochloride
- diphenoxylate hydrochloride with atropine sulphate
What is the mechanism of action of probiotic drugs?
Also known as intestinal flora modifiers and bacterial replacement drugs
Bacterial cultures of Lactobacillus organisms work by
Supplying missing bacteria to the gastrointestinal tract
Suppressing the growth of diarrhea-causing bacteria
What is one example of a probiotic?
Lactobacillus acidophilus
What indication is outlined for adsorbents?
Milder cases of diarrhea.
What indication is outlined for antimotility (anticholinergic and opiates) drugs?
More severe cases of diarrhea
What indication is outlined for probiotics?
Antibiotic induced diarrhea
What are some of the adverse effects of adsorbents?
Increased bleeding time Constipation, dark stools Confusion Tinnitus Metallic taste Blue gums or black tongue
What is the enteral route of medication?
The drug is absorbed into the systemic circulation through the mucosa of the stomach, small intestine, or large intestine.
What are examples of enteral route medications?
Oral
Sublingual
Buccal
Rectal (can also be topical)
What are parenteral routes of medication?
Intravenous (fastest delivery into the blood circulation) Intramuscular Subcutaneous Intradermal Intra-arterial Intrathecal Intra-articular
What are examples of topical routes of medication administration?
Skin (including transdermal patches) Eyes Ears Nose Lungs (inhalation) Rectum Vagina
What is distribution as it relates to pharmacokinetics?
Transport of a drug by the bloodstream to the drug’s site of action
What is the most common blood protein.
Albumin
Which blood protein carries the majority of protein-bound drug molecules?
Albumin
What can result from low albumin levels?
Drug toxicity as less drug will be available.
What occurs during metabolism of a drug?
Also referred to as biotransformation Biochemical alteration of a drug into - an inactive metabolite, - a more soluble compound, - a more potent metabolite (as in the conversion of an inactive prodrug to its active form), - or a less active metabolite
What happens during excretion?
Elimination of drugs from the body
Primary organ responsible is kidney
Liver and bowel also play a role
Renal excretion – affected by kidney disease
Biliary excretion – affected by liver disease
What do enzyme inhibitors do?
Decrease or delay metabolism
What do enzyme inducers do?
Stimulate metabolism
What is a drug’s half-life?
Half-life: time required for half (50%) of a given drug to be removed from the body during elimination phase
What is steady state?
Steady state: amount of drug removed via elimination = amount absorbed with each dose; takes about 4-5 half lives of drug administration
Steady state means consistent blood levels and correlates with maximum therapeutic benefits
When does drug toxicity occur?
If the peak blood level of the drug is too high.
What is therapeutic drug monitoring?
Used to monitor peak/trough, adequate therapeutic effects, minimize drug toxicity.
What is a non-selective interaction?
Disrupts cell process in various ways.
What is a teratogenic drug effect?
birth defects
What is a mutagenic effect?
permanent change in genes (radiation)
What is a carcinogenic effect?
cancer causing (excessive hormone therapies)
What are adverse effects of antocholinergics?
Urinary retention, sexual dysfunction
Headache, dizziness, confusion, anxiety, drowsiness
Dry skin, flushing
Blurred vision
Hypotension, bradycardia or tachycardia (yes, sorry!); think of it as precipitating abnormal cardiac rhythms
What are adverse effects of opioids?
Drowsiness, dizziness, lethargy Nausea, vomiting, constipation Respiratory depression Hypotension Urinary retention Flushing
True or False: Give bismuth subsalicylate to children or teenagers with chicken pox or influenza.
False. Don’t because of the risk of Reye’s syndrome.
What is constipation?
Abnormally infrequent and difficult passage of feces through the lower gastrointestinal tract
A symptom, not a disease
Disorder of movement through the colon or rectum
Can be caused by a variety of diseases or drugs
What are non-surgical treatments of constipation?
Dietary (e.g., fibre supplementation)
Behavioural (e.g., increased physical activity)
Pharmacological
List five types of laxatives.
Bulk forming Emollient (stool softeners, lubricant laxatives) Hyperosmotic Saline Stimulant
What is a bulk forming laxative and give one example.
High fibre
Absorb water to increase bulk
Distend bowel to initiate reflex bowel activity
Examples: psyllium (Metamucil®)
What is an emollient laxative? Give two examples.
Stool softeners and lubricants
Promote more water and fat in the stools
Lubricate the fecal material and intestinal walls
Examples
Stool softeners: docusate salts (Colace®)
Lubricants: mineral oil
What is a hyperosmotic laxative? What are three examples?
Increase fecal water content. Results in bowel distention, increased peristalsis, and evacuation
Examples
Polyethylene glycol
Glycerin
Lactulose (also used to reduce elevated serum ammonia levels)
What is a saline laxative? List 2 examples.
Increases osmotic pressure within the intestinal tract, causing more water to enter the intestines
Results in bowel distention, increased peristalsis, and evacuation
Examples
Magnesium hydroxide (Milk of Magnesia®)
Magnesium citrate
What is a stimulant laxative? List 2 examples.
Increase peristalsis via intestinal nerve stimulation
Examples
senna (Senokot®)
bisacodyl (Dulcolax®)
True or False. All laxatives can cause electrolyte imbalances.
True
What two neurotransmitters are imbalanced in Parkinson’s Disease?
dopamine and acetylcholine
At what point do symptoms of PD show up?
When about 80% of the dopamine stored in the substantia nigra of the basal ganglia is depleted
What are classic symptoms of PD?
Bradykinesia “TRAP” Tremor Rigidity Akinesia Postural instability
What is dyskenesia?
Difficulty in performing voluntary movements
What are two common types of dyskenesia?
Chorea: irregular, spasmodic, involuntary movements of the limbs or facial muscles
Dystonia: abnormal muscle tone leading to impaired or abnormal movements
What are most PD drug therapies aiming to accomplish?
Drug therapies are aimed at increasing the levels of dopamine or antagonizing the effects of ACh.
True or false. Levodopa is a precursor to dompamine.
True
How do direct acting dopamine receptor agonists work?
Work by direct stimulation of presynaptic dopamine receptors or postsynaptic dopamine receptors or both in the brain.
What is an example of an ergot derivative direct acting dopamine receptor agonist?
bromocriptine
How does bromocriptine work in PD?
Works by activating presynaptic dopamine receptors to stimulate the production of more dopamine
Also inhibits the production of the hormone prolactin, which stimulates normal lactation and can be used to treat women with excessive or undesired breast milk production (galactorrhea) and for treatment of prolactin-secreting tumours
In patients with what disease should caution be used when prescribing bromocriptine?
peripheral vascular disease
What are adverse reactions of bromocriptine?
GI upset, dyskinesias, sleep disturbances
What drug interactions exist for bromocriptine?
erythromycin and andrenergic drugs
What drug is paired with levodopa and why?
Carbidopa is given with levodopa.
Carbidopa does not cross the blood–brain barrier and prevents levodopa breakdown in the periphery.
As a result, more levodopa crosses the blood–brain barrier, where it can be converted to dopamine
What is an example of a replacement drug for PD?
Levodopa-carbidopa
What needs to be in place physiologically for levodopa to be effective?
Functioning nerve terminals
How long before levodopa cannot control PD?
5 - 10 years
What are adverse reactions resulting from levodopa therapy?
confusion, involuntary movements, GI distress, hypotension, cardiac dysrhythmias
When is levodopa-carbidopa contraindicated and when should it be used cautiously?
Contraindicated in cases of angle-closure glaucoma
Use cautiously in patients with open-angle glaucoma
True or false: levodopa can cross the blood brain barrier?
Levodopa is able to cross the blood–brain barrier, and then it is converted to dopamine.
However, large doses of levodopa needed to get dopamine to the brain also cause adverse effects.
What role does carbidopa play in getting levodopa across the blood brain barrier?
Carbidopa does not cross the blood–brain barrier and prevents levodopa breakdown in the periphery.
As a result, more levodopa crosses the blood–brain barrier, where it can be converted to dopamine.
Generally speaking, when does levodopa start to lose effectiveness?
After 5 - 10 years.
What are adverse effects of levodopa?
Confusion, involuntary movements, GI distress, hypotension, cardiac dysrhythmias.
What are adverse effects of levodopa-carbidopa?
Cardiac dysrhythmias, hypotension, chorea, muscle cramps, GI distress
What interactions exist for levodopa-carbidopa?
: pyridoxine, nonselective MAOIs, benzodiazepines, antipsychotics, dietary protein
What is the main effect of Sinemet CR? (levodopa-carbidopa)
Increases “on” time and decreases “off” time.
Can levodopa-carbidopa be taken with food?
Yes, to minimize GI upset. But it is best taken on an empty stomach.
What are two examples of Selective MOA Inhibitor Therapy?
- selegiline hydrochloride
- rasagiline mesylate
What do selegiline and rasagiline get used with?
Adjuncts with levodopa-carbidopa
What are contraindications of selegiline and rasagiline?
- known allergy
- use with meperidine
What are the adverse side effects of selegiline (MAO-B Inhibitor)
- dizziness, insomnia, hallucinations, ataxia, agitation, depression, paresthesia, somnolence, hype or hyper tension, nausea, diarrhea, chest pain, weight loss, rhinitis, pharyngitis
What is the primary role of MAO-B Inhibitors?
Causes an increase in the levels of dopaminergic stimulation in the brain. This helps to counter the dompaminergic deficiency seen in PD.
What dose is recommended for selegiline and rasagiline?
10 mg/day. Beyond that dose, watch out for the cheese effect!
Name one dopamine modulator.
Amantadine
How does amantadine, the only known dopamine modulator, work?
Appears to work by causing the release of dopamine and other catecholamines from their storage sites, in the presynaptic fibres of nerve cells within the basal ganglia that have not yet been destroyed by the disease process. Also blocks the reuptake of dopamine into the nerve fibres.
Is amantadine considered direct acting or indirect acting?
Indirect acting b/c does not directly stimulate dopaminergic receptors.
At what stage of PD is amantadine used typically and for how long is it usually effective?
Generally in early stages and effective for only 6 -12 months.
What are common adverse effects of amantadine?
Common adverse effects associated with amantadine are relatively mild and include dizziness, insomnia, and nausea.
What drug interactions exist for amantadine?
: increased anticholinergic adverse effects when given with anticholinergic drugs
Name one COMT inhibitor.
entacapone (Comtan)
What is the mechanism of action of entacapone?
Presynaptic; Blocks catechol ortho-methyltransferase (COMT), the enzyme that catalyzes the breakdown of the body’s catecholamines
True or false. Entacapone crosses the blood brain barrier and acts both within the CNS and the peripherally?
False. Cannot cross and only acts peripherally.
What positive effect does entacapone have?
It prolongs the duration of action of levodopa.
What are adverse effects of entacapone?
gastrointestinal (GI) upset, urine discoloration; can worsen dyskinesia that may already be present
What is anticholinergic therapy used for?
Used to treat muscle tremors and muscle rigidity associated with PD
These two symptoms are caused by excessive cholinergic activity.
Name one anticholinergic drug used for PD treatment.
benztropine
In what conditions should one use caution when taking benztropine?
Caution during hot weather or exercise because it may cause hyperthermia
What are adverse effects of benztropine?
Adverse effects: tachycardia, confusion, disorientation, toxic psychosis, urinary retention, dry throat, constipation, nausea, vomiting
What are some nursing implications related to implementation?
- Administer drugs as directed by manufacturer.
- Provide patient education regarding PD and the medication therapy.
- Inform the patient not to take other medications with PD drugs unless the patient checks with the physician.
- When starting dopaminergic drugs, assist patient with walking, because dizziness may occur.
- Administer oral doses with food to minimize GI upset.
- Encourage patient to take in at least 3 000 mL of fluids per day (unless contraindicated).
- Taking levodopa with MAOIs may result in hypertensive crisis.
When do therapeutic effects of PD drugs kick in?
Therapeutic effects of COMT inhibitors may be noticed within a few days; it may take weeks with other drugs.
What should the nurse monitor in terms of response to the PD drug treatment?
Improved sense of well-being and mental status
Increased appetite
Increased ability to perform activities of daily living, to concentrate, and to think clearly
Less-intense parkinsonian manifestations, such as less tremor, shuffling gait, muscle rigidity, and involuntary movements
List the following in order from fastest to slowest: Powders, liquids (elixirs, syrups), enteric coated tablets, capsules, suspension solutions, coated tablets, tablets
Liquids (elixirs, syrups) Suspension solutions Powders Capsules Tablets Coated tablets Enteric-coated tablets
What are the three components of a nursing diagnosis?
Part 1: Human response
Part 2: “related to” factors
Part 3: “as evidenced by” cues, clues, evidence or other data
