Exam 2 thera drug interactions Flashcards
Pharmacodynamic:Additive
When two drugs have similar pharmacodynamics (same therapeutic effect) and when pt takes them together leads to a exaggerated response but no change in the pharmacokinetics of the drugs
Ex pt take diphenhydramine (causes sedation) + Lorazepam (causes sedation) = greater cause of sedation
-Is pt specific
Drugs that require acidic pH for absorption
Ketoconazole
Dabigatran
Rilpivirine
Grapefruit
Inhibit the Pgp (p-glycoproteins in the intestinal)
so increase the absorbtion of Diltiazem and cyclosporine
Pharmacokinetic: Absorption
Chelation by Dairy
Decreases the absorption decreases the drug effects
Doxycycline
Quinolones- Ciprofloxacin , Levofloxacin
Alendronate
Methotrexate
Levothyroxine
Separate them 2 hrs from consuming dairy
Pharmacokinetic: Absorption
Chelation Ca, Mg, Fe
Ciprofloxacin- Administer 2 hrs before or 6 hrs after
Levofloxacin- Administer 2 hrs before or 2 hrs after
Moxifloxacin- Administer 4 hrs before or 8 hrs after
Tetracycline- Administer 2hrs before or 4 hrs after
Pharmacokinetic interaction: Absorption
Fiber
-Digoxin
-Levothyroxine
-Carbamazepine
-TCA
-Metformin
-Lithium
Pharmacokinetic: Distribution
Compete for the plasma binding protein
Only affect : Phenytoin and Warfarin
Substrate
Medication that is metabolize by the enzyme
It can be a substrate to multiple enzymes
Inducer
Speed up the enzyme activity
So when another drug pass throw that enzyme is going to be metabolize fast because of the inducer
So the concentration of the other drug is low because of fast metabolism
Inhibitor
A drug can inhibit a specific CYP450 enzyme and it blocks the metabolism of the other drugs that need to pass through that enzyme in order to be metabolize so because is inhibited there will be more drug concentration
CYP 3A4 Inhibitors
RACEGAVD
Ritonavir
-Azole antifungals
Cyclosporine
Erythromycin/Clarithromycin
-Grapefruit
-Amiodarone
-Verapamil
-Diltiazem
CYP 3A4 Inducers
Carbamazepine
Phenytoin
Sj’s Wort
Barbiturates (Phenobarbital)
Rafampin
CYP 3A4 Subtrates
Carbamazepine
Simvastatin
Lovastatin
Warfarin
Benzodiazepines (midazolam)
Amlodipine
Nifedepine
Apixaban
Rivaroxaban
Simvastatin do not exceed more than 20mg when taken with
Amiodarone
Amlodipine
Ranozalone
Simvastatin Should not exceed more than 10mg when taken with
Dialtiazem
Verapamil
Dronedarone
