Prescription Writing and Drug Evaluation Flashcards
Describe the role of federal, state and local governments in regulating the prescription writing process.
Federal: Controls what drugs may be prescribed or sold directly to the public through the FDA; Evaluates the safety and efficacy of new drugs prior to public availability; removes dietary supplements deemed unsafe; equivalency of brand name vs generic drugs; plasement of drugs into Rx vs non-Rx categories; determination of which Rx are designated as controlled substances.
State: Controls who may prescribe drugs through the licensing process of boards. Federal DEA controls prescribing of controlled substances
Local: may pass laws that concern drug use in their jurisdictions.
Summarize the preclinical and clinical phases (1-4) of the new drug approval process of the FDA
Preclinical: In vitro studies and animal testing (attempt to determine safe dosage range for humans, success leads to investigational new drug app)
Clinical trials in humans
Phase 1: Clinical pharmacology, 1 yr (is it safe, pharmacokinetics), very select normal volunteers, <100, toxicity and metabolism studies, determines if animal/human response differ significantly
Phase 2: Clinical investigation, 2 yrs, (does it work in patients) select patient pool 200-300, comparison to placebo or existing tx, safety and efficacy evaluated, may detect broader range of toxicities
Phase 3: Full scale clinical trial, 3 yrs (does it work, double blind?), 1000-6000 patients, efficiacy measured against established tx. Monitor adverse rxns from chronic use. May be omitted for drugs used in serious illness. Positive results may result in approval
Phase IV: Post marketing surveillance, manufacturers required to submit reports to the FDA of any adverse effects. Studies continue after approval, collect data on mortality/morbidity, study groups omitted during earlier phases due to increased risks, also patients w/ multiple dz.
Compare and contrast FDA regulation of prescription drugs vs. dietary supplements (DSHEA 1994).
FDA related drugs-
Efficacy: evidence req’d via clinical trials
Safety: Must be studied, found acceptable, and detailed in package insert
Dose and p.kinetics: established in phase 1-3 clinical trials
Dietary supplements:
Efficacy: no proof req’d
Safety: burden of proof w/ FDA to show unsafe
Dose: guidelines based on traditions
Pkinetics: often unknown
Distinguish the different categories of drug equivalency (pharmaceutical, biologic, and therapeutic) and the relevance to generic vs. brand name products.
Pharmaceutical equivalents: Same active ingredients in the same dosage formulations that have the same route of administration.
Bioequivalent: Major equivalency test req’d by FDA; pharmaceutical equivalent forumulations that display comparable bioavailability when studied under similar conditions.
Therapeutic equivalents: pharmaceutical equivalents that, when administered to the same individual in the same dosage regimen, provided the same efficacy and safety.
FDA requires equivalence in these three categories for generic drug formulations, mean bioavailability variation is less than 4%.
Describe the legal components of a written prescription in Colorado.
Physician name, degree (MD, DDS), physician address, physician phone number
Patient name, patient address (sometimes)
date of Rx,
Drug name and strength, quantity, dosing regimen
Refilling instructions
Physicians signature
DEA number
Convert apothecary/avoirdupois/household measures to metric equivalents (and vice-versa).
Weight:
65 mg= 1 grain
28.35 g= 1 ounce
1 kg= 2.2 lb
Volume: 0.05 mL= 1 drop 5 mL= 1 tsp 15 mL= 1 tbsp ~30 mL= 1 fl ounce 3.785 L= 1 gallon
List the Latin and English abbreviations for common medical terms or phrases.
Frequency/Timing: ac- before meals bid- twice a day hs- at bedtime pc- after meals prn- when needed qam- every morning qd- every day qid- 4 times a day qod- every other day stat- immediately tid- 3 times a day
Routes of administration: ad- right ear as/al- left ear au- both ears IA- intra-arterial IM- intramuscular IV- intravenous IVPB- IV piggyback od- right eye os/ol- left eye ou- both eyes po- by mouth, orally pr- per rectum sc-sq- subcutaneous vag- vaginally
Miscellaneous a- before c- with gtt- drop h- hour p- after qs- sufficient quantity s- without Sig- label
Describe the major elements of the Controlled Substances Act
Rx drugs and controlled substances are both evaluated by the FDA and are available by prescription only. RX drugs, however, have a very low abuse potential, while controlled substances have abuse potential.
Any prescription for a controlled substance requires a DEA number.
Schedule I drugs may not be prescribed.
Schedule II, III, IV requires a prescription (and schedule V in Colorado)
Schedule II must be in ink in prescriber’s handwriting (i.e. cannot be telephoned in) and cannot be refilled.
Shedule III and IV (and V in CO) may be telephoned in, and may be refilled 5 times in 6 months.
Examples for safe prescription writing
Write legibly
Use the metric system
Never trail with a zero
Abbreviations should be avoided
