Drug-drug Interactions Flashcards
What are the types of drug interactions?
Drug-drug interactions
Herbal - drug
Food - drug
Drink - drug
Pharmacogenetic
What is the object drug?
The drug whose activity is effected by such an interaction
What is the precipitation drug?
Agent which precipitates the interaction
Risk factors for DDI?
Patient specific:
Old age
Genetic polymorphism
Concomitant diseases
Drug specific:
Poly pharmacy
Narrow therapeutic range
Dose
Other factors:
Multiple prescribing physicians
Self-prescription
Prolonged length of hospital stay
What are he drugs that cause the most problems?
Anticoagulants
E.g warfarin etc
Drugs frequently involved in DDIs
Lithium Digoxin Warfarin Theophylline Cyclosporine Phenytoin Nngentamicin Fluconazole Linezolid
What does therapeutic drug monitoring ensure?
That blood levels are within the correct range.
Foods interacting with warfarin
Asparagus, broccoli, Brussel sprouts, cabbage
Green teas, ginseng
Tonia bean
Avocado
Fish oils
Soybeans
The probability of DDIs increase with
The amount of drugs being taken
Susceptible patients
Liver disease Renal impairment Diabetes myelitis Epilepsy Asthma
Pharmacodynamic interactions
Can be:
Antagonistic
Additive or synergistic
Interactions due to changes in drug transport
Due to fluid and electrolyte disturbances
Indirect interactions
Pharmacokinetic interactions
It’s possible for one drug to alter:
Absorption
Distribution
Metabolism
Elimination of another drug
Absorption interactions
Formation of insoluble complexes
Altered pH
Altered bacterial flora
Altered GIT motility
Gastric emptying is the
Rate limiting step
Who should definitely not take valproic acid?
Women who are within child-bearing age
