Test One: Dosage And Rx Writing Flashcards
Goal of pharmaceutical testing
Achieve therapeutic bioequivalence
When are products considered to be bioequivalent?
Similar AUC, peak concentration, and time to reach peak concentration
Oral formulations from fastest delivery to slowest (coated tablets, suspensions, solutions, tablets, capsules)
solutions, suspensions, capsules, tablets, and coated tablets
What oral dosage form is best for kids/elderly?
Liquids-solutions and suspensions
What is the rate-limiting step in the overall absorption of a drug from solution?
Gastric emptying
How are suspensions different from solutions?
These drugs are water insoluble
What is the rate limiting step for suspensions?
Rate of dissolution; longer rate= slower absorption
What is an advantage of solid dosage forms?
convenience of administration, accuracy and reproducibility of dosing, increased drug stability, and ease of mass production
What is the purpose of dilutants/fillers?
To ensure physical stability in capsules and aid in absorption–lactose
What can be a problem with lubricants (magnesium stearate) in capsules?
Very hydrophobic which can slow down drug dispersal into GI fluid
What is used for capsule disintegration?
Disintegrants (starch)
What is the most frequently used means of drug administration?
Tablets
What are the pros and cons of the high compression of tablets?
Pro: can fit more the of active ingredient into the tablet
Con: takes longer to disintegrate
Rate limiting step for tablets
Dissolution(can be increased with a more soluble form of the drug like a salt)
Why are coated tablets covered in enteric coating?
Delay disintegration until it reaches the small intestines (protects drug from stomach or vice versa). Cellulose acetate is insoluble between pH 1-3
What route of administration is particularly useful for drugs with short half lives?
Intravenous–offer more control with administration and concentration
What is required for drug absorption after intramuscular injection?
Some water solubility (ie morphine)
Which drugs should be administered subcutaneously?
Insulin and low molecular weight heparin
Major rate limiting steps of percutaneous administration of a drug
release of drug from the formulation and passage across the stratum corneum (examples of drugs: nicotine, scopolamine, and nitroglycerin)
What’s the advantage of prolonged release formulations?
Reducing dosing frequency while maintaining therapeutic drug concentrations (can be good for drugs with narrow margins of safety)
How does the delivery of a prodrug help with drug administration?
The drug (such as l-dopa) does not become activated until it reaches an enzyme or certain biological fluid. L-dopa can cross the BBB to then become it’s activated form -dopamine to treat Parkinson’s symptoms
Single entity vs combination formulations
Single has one active ingredient while combo has at least two. Analgesics are typically combo
What do you need in order to write scheduled prescriptions?
DEA number
Superscription
“Rx” or recipe
Inscription
Name of the drug and dosage (with unit) and form (ie: Amoxicillin, 500 mg capsules)
Subscription
Instructions to the pharmacist for dispensary information [ie: twenty (20) caps]
Transcription
Directions for the pt (signa)
Sig: take four (4) capsules one hour before every appt p.o.
How does the DEA classify substances?
Medicinal usefulness and dependence liability. Schedule I has highest abuse potential and lowest medicinal usefulness
Do all opioids and benzodiazepines require prescriptions?
Yes, they are all scheduled drugs
How often can each schedule be refilled?
We can’t prescribe schedule I, schedule II cannot be refilled, and controlled substances in schedules III, IV and V can be refilled five
times within 6 months,
Which regulations should we follow, state or federal?
Whichever one is the most strict
1 grain =?
65 mg
