Principles In Therapeutics Flashcards
Pharmacokinetics
Means “drug movement” - the study of the concentration of a drug during the processes of absorption, distribution, biotransformation (metabolism), and excretion of a drug.
“What the body does to the drug”
Pharmacodynamics
The study of the mechanism of drug action on living tissue at the cellular level.
“What the drug does to the body”
Variables that affect drug actions
- Age
- Pregnancy
- Body weight
- Gender-hormonal effects • Pathologic conditions
- Placebo response
- Dosage
- Route
- Drug-diet interactions.
- Drug-drug interations
- Antidote—drug can be given to antagonize the toxic effects of another drug
What is a prescription?
A prescription is a written, verbal, or electronic order from a practitioner or designated agent to a pharmacist for a particular medication for a specific patient.
What is the meaning of the symbol ‘Rx’?
Ancient Latin use sign ‘Rx’ as standard abbreviation for prescription
Who can prescribe?
Someone for whom the medication prescribed is within their scope of practice to prescribe such as. Basically medically practitioners such as:
– - Physicians
– - Dentist
–- Veterinary doctors
Basic components of a prescription
Head
Body
Closing
Components of head of prescription
- Name of the patient
- Age
- Sex
- Address
- Date of the prescription
- Hosp No
- Diagnosis
Components of the body of a prescription
- The Rx symbol
- Name of drug
- Dose, size or concentration of the drug
- Amount (frequency) to be dispensed
- Directions to the patient
Components of the closing of a prescription
• Prescriber ’s name & signature • Refill instructions • Dispenser ’s name & signature
Principles of good prescribing
- Clarity about the reasons for prescribing - Diagnosis + Impact
- Taking into account the patient’s medication history before prescribing
- Ensuring to account for other factors that might alter the benefits and risks of treatment
- Safeguarding the patient’s ideas, concerns, and expectations
- Selection of effective, safe, and cost effective medicines individualised for the patient
- Adhering to national guidelines and local formularies where appropriate
- Writing clearly and unambiguously
- Monitoring the beneficial and adverse effects of medicines
- Prescribe within the limitations of your knowledge, skills and experience
How to avoid ambiguity
- Careful use of decimal points to avoid ambiguity
- “mL” is used instead of “cc” or “cm3”
- Directions written out in full in English
- Avoiding units such as “teaspoons” or “tablespoons”.
- Avoid abbreviation or use standard ones
- Micrograms are abbreviated “mcg” rather than “μg”
- Don’t write multiple drugs per prescription, it can add to confusion.
- Keep it simple.
Six rights that make a good prescription
- Right patient
- Right drug
- Right dose
- Right route
- Right time
- Right documentation
Principles of accurate drug administration
- Minimize the use of abbreviations
- Calculate dosages correctly
- Measure doses accurately
- Use appropriate anatomic landmarks to identify sites of IM injections-follow manufacturers recommendations
- Verify client identity
Types of medication orders
- Written orders
- Verbal orders
- Standing orders
- Stat orders
Parts of a medication order
• The full name of the patient • Generic or trade name of the drug • The dose, the route and frequency of administration • Date, time and signature of the prescriber
PO
– per os – by mouth
IM
Intramuscular
