Lecture 12 Flashcards
What is pharmacokinetics?
The fate of drugs and chemical substances once administered
What is the purpose of Pharmacokinetics?
Focuses on the concentration of drug in blood plasma
Why is the dosage regimen important in pharmacokinetics?
Determines the therapuetic benefit for a patient
What is the optimal dosing regimen?
- Max therapuetic effect
- Miniumum adverse effect
- Pharmacokinetic principles for the patient based on their specific information and the drugs pharmacokinetic behaviour
What is the absoprtion phase after adminsitration?
Tablet in the stomach, dissolves and aborption occurs
What is Cpmax?
Highest plasma concentration
What is the elimination phase?
Rate of drug removal from the blood exceeds the rate of absorption
What occurs to the concentration of plasma during the elimination phase?
Declines
What is the Therapuetic range?
A range of concentration of plasma where the therapuetic response is obatained and toxic effects are avoided
What is MEC and MSC?
• MEC – Minimum effective concentration
• MSC – Maximum safe concentration
What is the onset?
Time required to achieve the MEC following administration of the drug dose
What must happen in MEC?
minimum concentration of drug must be reached in the plasma before the desired therapeutic effect is achieved
What is the duration in Therapeutic widow?
Period which the concentration of drug in the plasma exceeds the MEC
What is the area under plasma concentration curve?
Total amount of drug absorbed into the systemic circulation folloiwng a dose
What is Zero order kinetics of absorption?
Rate of drug absorption is constant and independnt of the dose administered
What is first order kinetics of absorption
Rate of reaction which it is dependant ont he concentration of a drug in the body
What is the Zero order eliminatin?
Elimination is independent on the drug concentration in the body
Why is it not possible for the body to metabolise faster once saturated?
Not enough carriers to pass through the membrane
Why is IV infusion used?
- Fast onset and 100% bioavailability
- For emergencies
- Adminsters drugs at a fixed rate
What is Css?
The rate of elimination of drug is equal to the rate of IV infusion
What is the time taken to reach Css dependent on?
Half-life (t1/2) of the drug
What is the meaning of Css?
Maximum clinical effectiveness
What is Alcohol Absorption Rate dependent on?
Gastric emptying rate
Ethanol Concentration
What does empty stomach (fasting) do to the Gastic Emptying Rate?
Increases
