Clin Pharm Exam I - Learning Objectives Flashcards
What is the FDA responsible for in terms of drugs?
What types of medications does this NOT cover?
- Drug safety in animals, people, the environment, and the food supply
- Safety and efficacy (the product will consistently and uniformly perform as the label claims it will
DOES NOT COVER
- Neutraceuticals, compounded drugs, or FDA-approved drugs used extra-label
What government agency is responsible for regulating veterinary drug use?
FDA
Where do you report an adverse drug interaction?
FDA website
What is the definition of prescription drugs?
They can only be dispensed by a licensed DVM or on the written order of one.
Must be labeled with “Federal law restricts these drugs to use by or on the order of a licensed veterinarian”
What are the components of the veterinary-patient-client-relationship (VPCR)?
- Responsible for clinical judgement about the health of patient and need for treatment
- Client agrees to follow your directions
- You have knowledge about the patient (recently had a PE, personally acquainted with the care and keep of patient)
- Available for follow ups
What is the minimum information required to be a on the label of a dispensed veterinary drug?
- Name/address of dispenser
- Date of order/when filled
- Name/address of veterinarian who prescribed the drug
- Directions for use
- Any necessary warning/precautionary statements including withdrawal times
Under AMDUCA, what does the FDA have the right to prohibit in food animals?
Extra-label drug use of certain drugs
What drugs are specifically prohibited for use in food animals?
1) Chloramphenicol
2) Clenbuterol
3) Diethylstilbestrol (DES)
4) Dimetridazole/nitromidazoles
5) Furazolidine/nitrofurazone
6) ELDU of fluoroquinolones
7) Glycopeptides
8) Sulfonamide drugs (lactating dairy cattle)
9) Phenylbutazone (Female dairy cattle >20 mo)
10) Cephalosporins
11) Adamantane/neurimidase inhibitors (ELDU in poultry)
What is the definition of extra-label drug use?
Actual or intedned use of a drug in an animal in a manner that is not in accordance with the FDA approved labeling
- Use in different species
- Different dosage
- Frequency
- Route of administration
- Deviation from labeled withdrawal time
When is extra-label drug use (ELDU) permitted by the FDA?
- Within the scope of a VCPR
- When health of animal is threatened, or suffering/death may result from non-treatment
- No animal drug approved for use
- Animal drug is approved, but doesn’t have needed active ingredient, not required dosage/concentration, or is clinically ineffective when used as labeled
What are the absolute requirements for ELDU in food animals?
- Diagnose and evaluate the condition for which you are prescribing
- Ensure client maintains ID of treated animals
- Establish an extended withdrawal time
- Ensure no illegal drug residues will occur
- Have thorough record keeping
- ELDU can never be used for enhanced production
What is the definition of a compounded drug?
- Any manipulation of an FDA approved drug
- Drug formulated from bulk chemical that is not approved by the FDA
Includes
- Mixing formulation
- Crushing/breaking tablets
- Adding flavoring to a commercially available oral solution
- Not following label indications for prep of formulation, using different dilution factor/diluent, mixing different drug proportions
When does the FDA allow the use of compounded drugs?
- Valid VCPR
- Health of animal is threatened or suffering
- No FDA commercial animal or human drug available
- Product is made from an FDA approved human or animal drug
- Compounded drug must be safe and effective
- Amount of product is made on an individual basis
- Food animals MUST be provided with an extended withdrawal time
What are the advantages of compounded drugs?
- Discontinued FDA approved formulation
- Patient is allergic to agents in FDA approved products
- Tailored dosage strengths
- Palatability/dosage form changes
- Drug shortages
What are some disadvantages of compounded drugs?
- No monitoring of manufacturing process
- No inspected facilities
- Drug stability is unknown
- No assessment of purity or potency
What are some possible consequences on drug effect that are inherent with compounded drugs?
- Suboptimal effect
- Toxicity
- Time of onset
- Intensity/duration
- Residue elimination/withdrawal time
How do you recognize if a drug is FDA approved?
NADA number listed on label
What is a controlled substance?
A prescription drug that is placed into a schedule based on:
- Current accepted medical use
- Relative abuse potential
- Liklihood of causing dependence when abused
What qualifies a Schedule I drug?
Give examples.
- No currently accepted medical use in the US
- Lack of accepted safety for use
- High potential for abuse
Heroin, LSD
What qualifies a Schedule II drug?
Give examples.
- High potential for abuse
- Severe psychological or physical dependence
Hydromorphone, methadone, fentanyl
What qualifies a Schedule III drug?
Give examples.
- Potential for abuse less than II
- Abuse may lead to moderate or low physical dependence, OR high psychological dependence
Buprenorphine, products with less than 90 mg of codeine
What qualifies a schedule V drug?
Give examples.
- Low potential for abuse
Alprazolam, diazepam, lorazepam, midazolam
What qualifies a Schedule V drug?
Give examples.
- Very low potential for abuse
Preparations with limited quantities of certain narcotics
- Cough medications with no more than 200 mg codeine per 100 ml/G - Robitussin AC, ezogabine
What are special considerations with controlled substances?
- Requirements for schedules can change
- Registration with DEA and state BOP
- Thorough recordkeeping
- Special Ordering requirements
- Special prescribing requirements
- Special security measures
What regulatory steps are required to dispense drugs once you are a practicing veterinarian?
- Know VCPR responsibilities
- Know state laws for prescribing and dispensing
- Know special considerations for food animals
- Know how to report adverse drug reactions
- Know regulations about ELDU and compounding
- Know how to maintain records
- Contact DEA for registration
What is the definition of a drug-to-drug interaction (DDI)?
The pharmacological effects of a drug are altered by the prior or co-administration of another drug(s) that can be uni or bidirectional
What are the three main types of mechanisms for DDI?
- Pharmacokinetic
- Pharmaceutical
- Pharmacodynamic
What are the five main pharmacokinetic DDI mechanisms?
1) Change in site of action of concentration –> change in drug effects
2) Change bioavailability
3) Change pH of GI, binding in GI, GI motility, or mal-absorption
4) Displace object drug from its binding site
5) Can induce or block metabolism of drugs
What are the three ways a DDI can affect pharmacodynamics?
1) Synergistic
2) Additive
3) Antagonistic
What are some examples of synergistic pharmacodynamic DDIs?
- Nephrotoxicity with aminoglycosides and NSAIDs
- Neuromuscular blockage w/ inhalent anesthetics and aminoglycosides
- Amoxi-clav/TMS
What is an example of an additive pharmacodynamic DDI?
Cardiovascular effects with detomidine and injectable TMS
What is an example of an antagonistic pharmacodynamic DDI?
Naloxone and opioids
What are some common DDIs seen in clinical practice?
- Metaclopramide & behavioral drugs
- Furosemide & amphotercin/gentamycin
- Fluroquinolones & theophylline
- Chloramphenicol & theophylline
- Fluozetine & seligiline
- Digoxin & quinidine
- Ketoconazole & cyclosporin/ivermectin/digoxin/warfarin
- Epinephrine & acepromazine
- Atropine & alpha2 agonists
- ECAi & digoxin
- Phenobarbitol & mitotane/thyophylline/digoxin/lidocaine (dogs)
What are the main ways to detect DDIs?
Understand the mode of action of a DDI
- Know PK features
- Is it a high risk drug?
- Is the interaction pharmacodynamic?
ID potential or real clinical outcomes
- Does the patient have new problems due to the DDI?
- Is the patient high risk?
What are the main ways to manage DDIs?
- Define true clinical consequences of DDI
- Know how to use and have antagonist/reversal drugs on hand
- Consider use of emergency drugs
- Discontinue the drug suspected of causing the DDI, if possible
- Decrease dose or change time of administration
What is therapeutic drug monitoring?
A tool for guiding the design of an effective and safe regimen for drug therapy in an individual patient.
What is drug monitoring used for?
To confirm a plasma drug concentration (PDC) that is above or below the therapeutic range
What are the basic components of pharmacokinetics relevant to therapeutic drug monitoring?
- Fixed dosing is intended to generate PDS within a therapeutic range
- Marked individual variability has been confirmed due to physiologic, pathologic, and pharmacologic effects
- Need to modify dosing when possible based on an individuals needs
What are the general guidelines for therapeutic dose monitoring? (5)
- Patient response to the drug must correlate with PDC
- Make sure to measure that active part (parent compound vs. active metabolite)
- Samples need to be able to measure drug at therapeutic concentrations, and be detected rapidly, precisely, and accurately
- Monitoring is most effective when max/minimum ranges have been established
- PDC ranges encompass 95% of all cases (5% of cases will not response to established values)
Trial and error method for TDM works when drugs can be easily __________.
Give examples.
Measured
Gas inhalants
Rapidly acting anticonvulsants
Lidocaine for ventricular arrhthmias
Trial and error method for TDM works well when the disease process:
- Is not serious
- Doesn’t require immediate resolution
- Drugs w/ wide therapeutic windows
When should you NOT use the trial and error approach for TDM?
- Drug response cannot be easily measured
- Drug has narrow margin of safety
- Patient’s life is threatened
When is TDM most useful?
- Drugs that can cause serious toxicity
- Poorly defined clinical endpoint
- Steep dose-response curve
- Narrow therapeutic range
- Nonlinear pharmacokinetics
- Combo drugs w/ potentially undesirable side effects
- When therapeutic failure may lead to patient harm (anticonvulsants)
- A target therapeutic range has been validated in the target species with the target drug
When measuring TD<, when do you take a peak value?
If toxicity of drug is a concern
When measuring TDM, when do you take a trough value?
If efficacy of drug is a concern
What are some drugs commonly monitored using TDM?
- Amikacin
- Bromide
- Cyclosporin
- Digoxin
- Gabapentin
- Gentamycin
- Leflunomide
- Levitiracetam
- Lidocaine
- Phenobarbitol
- Phenytoin
- Procainamide
- Theophylline
- Valproic acid
- Vancomycin
- Zonisamide
