Medications__NOT Top 200 Drugs (20% approx) Flashcards
What are the 4 Concepts of medicine?
- Prevent, e.g. vaccine
- Cure: e.g. antibiotics
- Alleviate, e.g. ondansetron (for cancer)
- Manage: e.g. insulin
Cure is rare, manage more common.
What are the 2 key pharmacology terms?
1) Pharmacodynamics: What drug does to body. Generally invols drug getting absorb or inject into bloodstream, bind to target receptor in body.
AGONISTS: Drugs that exert effect by activate receptor.
ANTAGONISTS: Drugs that block other subs from activate receptor.
2) Pharmacokinetics: What body does to drug.
ABSORPTION: Drugs absorb into circulation.
DISTRIBUTION: Drugs vary in extent and areas reach in body.
METABOLISM: Drugs broken down by various enzymes and carry across membranes by transporters. Liver primary site of drug metab, though other organs can be involve.
ELIMINATION: Eventual, drugs elim by urine, feces, and/or destruct inside body.
What are Bioavability, Vol of Distrib, Metabolites?
Bioavail: % OF ADMIN DOES THAT ENTERS CIRCULATION, .e.g. if goes into bloodstream (by inject) then 100%. Oral is much less, e.g. 20, 30%, but other orals at/close to 100%.
Vol of distribution: How WIDELY DISTRIB IN THE BODY. Higher vols mean greater circulation once in bloodstream.
Metabolites: Substance that RESULTS FROM METAB OF ORIGINAL MEDICATION. Can have therapeutic or adverse effects. They CAN BE THE ACTIVE DRUG ITSELF.
Brand vs Generic drugs?
Brand: trademark name. Molecules can have many brand names.
Generic: Desribe unique chemical molecule. On market when brand rights expire. Same generic name across all brands.
• Must have same dosage as brand of active ingredient.
• Must also display bioequiv to brand name product.
- Interchange Generic for Brand
State laws different.
In general, pharmacists can sustit generic for brand product, unless:
• Physician indicates cannot
• State laws restrict. May be case for “narrow therapeutic index” drugs.
“Orange” Book: Determine therapeutic equivalent.
• If product is “AP rated”, then generic=brand.
• FDA maintains Orange Book
“Purple Book”: Determines if prods are “biosimilar”.
Role of Pharma Technician?
1) Prepare or compound medications per prescription order verify by pharmacist or general stock. May include doing calculations on wgt, vol, quantity; and sterile compounding of injectable drugs;
2) Collect patient info and demos, health/med history, financial info;
3) Process claims and interact w/insurance cos for authorization;
• Order medics, manage invent, use info systems for order and distrib;
• Administer vaccinations.
Active/Inactive ingredients
- Drug product = dosage forms, to be admin to patient
- Active ingred – actual medication.
- Inactive ingred, or excipient also likely present
- ** Excipient purposes
1) Preservation
2) Improve solubility
3) Flavoring
4) Bulking
5) Molding - Dosage form design to be compatib w/intended site of admin
- Once dosage form administer, active drug ingred is liberate from dosage form so can be absorbed.
Solids Dosage Forms.
These are the most common.
- Tablets : Drug compact into molded dosage. Enteric coating may be use to keep drug from dissolve too soon in GI tract. Enteric should not be chew, crush, split. Some forms meant to be chew, dissolve under tongue, absorb into cheek, vaginal insert. Effervescent tablets dissolve liquid.
- Capsules: Drug in powder, granules or liquid w/in hard gelatin shell.
- Extended release Tabs/Capsules
• Extend release formul results more prolong absorption of medic, more stable concentrate in blood over time.
• Intent may be to prolong action, reduce need of freq of admin and/or minimize side effects.
• Extend-release dose form should not be crush, broken, chew
• Many diff names, e.g. extend release (ER), Delay response (DR), Control release (CR), Long act (LA). - Lozenges: Hard, sugar, oval, dissolve in mouth
- Suppositories: Mold dosage, soft than tabs, Rectal, vagina, urethral admin.
- Inhalants: Respiratory admin thru inhaler; patient forcefully inhales.
- Aerosols: Drugs formulate into gas mix for use in nebulizer or inhaler; mechanical pushed.
- Powders: Fine particles for liquid dose, topical or inhalant.
- Granules: compacted particles of drug, usual in capsule to be open for oral admin.
- Patches: drug in patch for topical or transdermal (apply into skin)
- Implants: Can be pump system or hardware implanted for long-term release
Liquid Dosage forms
- Drugs can be dissolve or suspend into liq for admin via various routes
• Can be good as oral medic for patients WHO CANNOT SWALLOW SOLID DOSES, or who need specific doses not feasib w/solid
• Use of liquid dose form introduces added step: careful measure
• Usual SHORTER SHELF LIFE - Solutions: Drug DISSOLVE EVENLY
- Suspensions: UNDISSOLVE DRUG MIX INTO FLUID; must be shaken. Include LOTION&GELS.
- Emulsions: Like suspension, mix of lipid or oil medium into liquid medium.
- Syrups: Contain SUGAR
- Jellies: High water content
- Elixirs: Mix of WATER & ALCOHOL
- Spirits: Concentrate alcohol solution
- Extracts: CONCENTRATE DRUG SOLUTION result from extract of drug using solvent. Can be modify into tincture (medicine made by dissolve drug into alcohol) using alcohol solution to dilute drug to 100 mg/ml.
Routes of admin medicine (Enteral vs. Parenteral)
Enteral Routes (avoid GI tract)
1) Oral (PO) – Medic taken by mouth and swallow. May result slower onset of action, and maybe lower bioavail.
2) Sublingual (SO) – Medic dissolve under tongue
3) Buccal – Medic dissolve against cheek.
4) Feed Tube – Drug admin via nasogastric tube (NGT, NG tube), nasojejunal, gastrostomy, PEG tube.
Parenteral Routes (avoid GI tract)
A) Intraven (IV) – Direct inject into vein. Can be quickly as bolus or push, or slowly as infusion.
B) Intradermal – Inject into top few layers of skin.
C) Sub-cantaneous (SQ) – inject under skin.
D) Intramusc (IM) – Into large muscle, larger needle.
OTHERS
Topical – apply to skin, limited system absorb.
Transdermal – apply to skin but intend for absorb into circulate.
Otic – apply ear canal. AU- both ears. AD- right ear. AS- left ear.
Ophthalmic – onto eye. OU- both eyes. OD- right eye. OS- left eye.
PharmacoDYNAMIC vs. PharmacoKINETIC?
PharmacoDYNAMIC (DRUG AFFECTS BODY) drug interactions
- ADDITIVE: Drugs w/similar effects result in those effects added toget.
- SYNERGISTIC: Drug effects are amplify in combo to result in effect that is more pronounced.
- ANTAGONISTIC: Drugs effectively counteract each other.
PharmacoKINETIC (BODY AFFECTS DRUG) drug interactions
ADME: ABSORPTION, DISTRIBUTION, METABOLISM, EXCRETION
- Chgs in absorption: Some drugs may inhibit or enhance absorb of other drugs
- Chgs in drug metab:
o One of most common mechs for drug interacts
o Some drugs inhibit activity of enzymes or drug transporters (impaired absorb)
** Usually results in slow drug metab and more pronounce effects
o Some drugs induce active of enzymes or drug transporters
** Usual result in more rapid metab and less pronounce effects - Chgs in drug eliminate: Rare – drug may decrease renal or hepatic (via liver) drug clearance and thus increase effect of other drugs cleared by those pathways.
What is contraindication?
Contraindications: Infers drug should NOT be used due to concern for partic patient.
- Absolute: Avoid at all costs, risks much higher than benefits;
- Relative: Should be avoid unless strong benefit that outweighs risk.
*Reasons can include o Allergy o Existing health condits o Drug interact o Genetics o Age or disease related chgs in organ function
Drugs prone to drug interaction problems
- AMIODARONE (Antiarrhythmic):
o Metabolize by several enzymes that often implicate in drug interacts.
o Prolongs “QT Interval” – can have addictive effect when combine w/drug(s) that do the same.
o Increase risk for potential fatal heart arrythmia called “torsades de pointes” - ANTIDEPRESSANTS & ANTIPSYCHOTICS: Cause many side effects – easy for additive, synergistic effects to occur when combine w/other drugs.
- DIGOXIN (Anti-arrhythmic and Blood pressure support): Metab by several enzymes that often implicate in drug interacts.
- DRUGS FOR EPILEPSY: Commonly metab by enzymes that prone to interactions. Often have narrow therapeutic index (=small differ in dose or blood concentrate can lead to serious therapeutic failures), so small chgs in metab can be very serious.
- WARFARIN (It can treat and prevent blood clots): Metab by many enzymes that can be affect in drug interactions. Dietary Vit K intake (green, leafy vegs) can reduce treatment effect.
What are Narrow Therapeutic Index Drugs?
Drugs in which small chgs in dose or serum can lead to signif changes in effect or toxicity.
• “Critical dose” drugs
- SUBtherapeutic: drug dose or concentrate below what needed to be effective (too low)
- SUPRAtherapeutic: drug dose or concentrate above point at which drug is safe, pose risk of toxicity (too high)
Characters of Narrow Therapeutic Index drugs
- There is little diff between Subtherapeutic and Supratherapeutic doses or mean concentrations.
- Subtherapeutic concentrates result in marked therapeutic failure. E.g. anti-epilectic
- Serum concentrates or other markers of drug activity are monitored.
- Dose changes tend to be done in small increments.
Prime examples of Narrow Therapeutic Index Drugs?
Narrow Therapeutic Index drugs
- Cyclosporine and tacrolimus
• Both are immune suppressive drugs use prevent transplant organ rejection.
• Serum concentrate monitor require.
o Subtherapeutic concentrates can lead to transplant reject.
• Toxicity charact by kidney failure. - Digoxin
• Serum concentrate monitor required.
• Drug interacts or reduce kidney function increase risk for supratherapeutic levels.
• Side effects include nausea, vomit, bradycardia, life-threaten arrhythmias. - Carbamazepine, phenytoin, valproic acid
• Serum concentrate require monitoring
o Doses & target levels may depend on patient seizure threshold
• Subtherapeutic concentrates can lead to break-thru seizures, while supratherapeutic can lead to numerous toxicities - Levothyroxine
• Monitor of thyroid stimulate hormone (TSH) required
o Increases in TSH indicate lower drug effect and vice versa - Lithium carbonate
• Serum concentrate monitor required
• Toxicity includes tremors, alter mental states, kidney fail – can be long lasting. - Theophylline
• Older, not used much now, have safer drugs. Used for asthma and COPD
• Serum concentrate monitoring require
• Toxicity includes arrhythmias, seizures, metabolic disorders - Warfarin (most famous NI drug of all time perhaps)
• Require monitor of INR, which measure of ability of blood to clot; (high INR means thinner blood, low INR means thicker blook).
o Higher INR levels indicate slower clot times, whereas lower INR means faster clot times
• Subtherapeutic concentrates can lead to strokes or other blood clots
• Supratherapeutic concentrates can lead to bleeding, range from mild to life-threaten (e.g. brain hemorrage)
• Numerous drug and food interacts and genetic diffs make this drug especial problematic.
Defining Stability
According to USP GEN CHAP 795, stability define as “The extent to which a preparation RETAINS, within specified limits and t/out its period of storage and use, the SAME PROPERTIES AND CHARACTERISTICS THAT IT POSSESSED AT TIME OF COMPOUNDING.
Stability import consider for all drugs, but espec those that are either compounded or have properties, storage or handle considerations that may RENDER THEM UNSTABLE IN SHORT PERS OF TIME.
• Compounded or admix drugs, drugs that do not remain stable at room temp, injectables, etc.
• The chemical nature of excipients of a compound and interact of those excipients determine its stability.
Beyond Use Dating (BUD)
The date after which a compounded prep shall not be used; determine FROM DATE PREP IS COMPOUNDED
- Replaces the expiration date determine by manuf ONCE:
o A drug is administer or compounded
o Dust cover is removed from base solution
o A drug that reqs refrig for long-term storage is removed and kept at room temp. - The BUD CANNOT BE LATER THAN EXPIRATION DATE OF ANY COMPONENT of the preparation.
USP general chapter 795 Recommends for Nonsterile Compounds
• The BUD should be conservative assigned base on drug-specific and general stability info.
• In absence of specific drug stability document, recs for BUD of non-sterile compounds is:
o “NON-AQUEOUS (NON-WATER CONTAINING) formulations: no later than the earliest expiration of indiv components OR 6 MONTHS”
• AQUEOUS ORAL FORMULATIONS: NO LATER THAN 14 DAYS stored at room temperature.
• AQUEOUS TOPICAL, DERMAL, OR MUCOSAL LIQUID AND SEMI-SOLID PREPS: no later than 30 DAYS STORED AT ROOM TEMPERATURE.
Stability and storage of insulin, injectables, vaccines
Stability and storage of insulin
- Insulin stored AT REFRIGER TEMPS (2-8C) PRIOR TO USE.
- Recco storage temps and discard by dating during use vary by formula and manuf
o Store in refrig while use some formulations may extend useable shelf life - Generally, in use INSULIN PRODS CAN BE STORED AT ROOM TEMP WITH BUD OF 28 DAYS.
Stability and storage of injectables
- Important to distinguish btween stability and sterility.
o Sterility – import concept w/sterile compounds, date must take into account the period of time in which compound can remain free of microbial contamination.
o USP Chapt 797: address sterile compound, include compound reqs, sterility test, dating. - Manuf reccos for injectable drugs should be use when deter storage temp and beyond use dating.
o Examps: GLP-2 agonists for diabetes, interferons for multiple sclerosis.
Stability and storage of Vaccines
- STABILITY IS OF PARTIC IMPORTANCE W/VACCINE PREPS
o Many probs exist in regards to temp, light, and adjuvant sensitivity.
o Live attenuated bacterial (LAB) other vaccines may also be high sensitive to residual moisture and UV light. - REFRIG (2-8 C) IS CRITICAL REQUIREMENT.
o Reqs cold chain supply logistics
o Careful inspection upon shipment receipt
o Use of temp monitor devices w/appropriate surveillance - Refer to manuf specific reccos for beyond use dating
o Include reccos for BUD post admixture in prods require reconstitution.
What drug can cause additive depression of the CNS (somnolence)? It can also add to risk of liver toxicity (hepatotoxicity)?
ALCOHOL: Can cause additive depression of the CNS (somnolence) with drugs that have those effects: OPIATES, BENZODIAZEPINES, MUSCLE RELAXANTS. Can add to risk of liver toxicity (hepatotoxicity) w/other known hepatotoxins, i.e. drugs that damage liver (e.g. ACETEMINPHEN).
What drugs decrease absorption of other drugs?
Antacids: Many can decrease absorp of other drugs, make less effect.
What drugs can have additive sedative effects w/other sedate medications?
Anti-histamines (histamine receptor blockers): Can have additive sedative effects w/other sedate medics.
