Prezentace aplikace PowerPoint

1
Clinical importance of interactions
2
Combinations

• Possitive interaction summation
• 112
• potentiation
• 113
• Negative interaction decreased effect

3
5R

• Right drug drug for the diagnosis
• Right dose estimated therapeutic dose
• Right time drugs at developped disease loose
  effectivity
• Right form - drugs as insulin must be
  administered as s.c. injection, if administered
  perorally, they dissolve in GIT
• Right patient is the one who needs the drug and
  we know his risk profile

4
Factors Increasing Risk of Drug Interactions

• Polypharmacy
• Polymorbidity
• Treatment lasting long time
• Chronic disease
• Combination of drugs with similar effect
• Low therapeutic index
• Simultaneous ordination of more drugs by
  different physicians
• Abuses
• Self-treatment

5
Drugs with High Risk

• Peroral antidiabetics
• Peroral anticoagulants
• Heart glykosides
• Antiepileptic drugs
• Antimanic drugs
• NSA
• Antibiotics

6
Division

• according to the level at which they arise
• pharmaceutic physical and chemical
  incompatibility
• pharmacocinetic absorption
  distribution
  biotransformation
  excretion
• pharmacodynamic

7
Absorption

• pH in GIT antacids
• motility of GIT prokinetics
  antidiarrhoea drugs drugs causing
  obstipation

8
Distribution

• Insufficiency of plasmatic proteins
  hepatopathy
• Binding to plasmatic proteins
• Benzodiazepine site
• Warfarin site

9
Biotransformation

• Enzyme system CYP 450
• Inductors
• E.g. barbiturates, hydantoin antiepileptics ...
• Also cigarette smoke
• Inhibitors
• E.g. azol antimycotics, diltiazem ...
• Also grapefruit juice

10
Pharmacodynamic Interactions

• Most often potentiation of sedative effect on CNS
  (benzodiasepines and alcohol)
• Also potentiation of bradycardia (verapamil a
  betablockers)
• Dangerous simultaneous administration of
  warfarin and aspirin