Drug Interactions (Allen-Durrance) Flashcards
Drug list (10)
- Levetiracetam
- Phenobarbital
- Cimetidine
- Chloramphenicol
- Ketoconazole
- Omeprazole
- Sucralfate
- Diazepam
- Potassium Bromide
- Digoxin
Collard greens have vitamin K
Interact with warfarin
Potassium Bromide interaction in FL
NaCl
Dogs drinking salt water when on Potassium Bromide
Polypharmacy
When you administer multiple drugs for one patient
Possible Drug interaction consequences
None
Altered therapuetic efficacy
Altered duration of action
Altered intensity of side effects
Novel effects
Drug interaction categories
- Incompatibilites
- Pharmacokinetic interactions
* some drug interactions is altering plasma level of drug - Pharmacodynamic interactions
* modulating drugs affect at a given plasma concentration
Physical incompatibilities
Separation
Chemical Incompatibilies
- Precipitation
- Chelation
- Binding
Consequences of Incompatibilites
Damage from toxic compounds
Particulate emboli
Tissue irritation (pH changes)
Therapeutic failure
Drugs incompatible with EVERYTHING
1.
2.
3.
4.
5.
6.
- Aminoglycosides
* Stop fluids even - Diazepam
* Likes to precipitate - Digitalis glycosides
- Pentobarbital
- Sodium bicarbonate
- Theophylline derivatives
Drugs with limited compatibility
1.
2.
3.
4.
5.
6.
- Dobutamine
- Dopamine
- Epinephrine
- Norepinephrin
- Tetracyclines: Doxy
- Parenteral antifungals: amphotericin D
Ketamine and Diazepam
Precipitates
Doxycycline and Calcium Gluconate
Chelation
Doxy and patient with chronic kidney disease
Kidney disease
- Cant bind phospohrus
- Give aluminum hydroxide to bind excess phosphorus
Aluminum hydroxide precipitates with the doxy I think
- Gets pooped out
Tums
Calcium supplements
Hyperparathyroidism post-op can cause hypocalcemia
Drugs that bind to plastic
Insulin
Diazepam
Diazepam
- Bind to plastic
- Light sensitive
- Now replaced by midazolam (none of these problems)
Sulcralfate
Bind irritated areas in the stomach and coats stomach
Drugs it Binds to (which then get pooped out)
- Tetracyclines
- Fluoroquinolones
- Cimetidine
- Phenobarbital
- Griseofulvin (antifungal)
Pharmacokinetic Interactions
Common changes in
- Absorption
- Distribution
- Metabolism
- Elimination
Drugs that increase pH of stomach
Drug examples
- Omeprazole
- Famotidine
- Antacids
Decreases absorption of weak acids
- Ketoconazole
Increase absorption of weak bases
*This can be a longer term interaction, prolonged increase of stomach pH
Gastric pH changes on Absorption
Inc pH
- antacids increase pH
- increases absorption of weak bases
- decreases absorption of weak acids
Dec pH
- inc absorption of weak acids
- dec absorptio of weak bases
Metoclopramide
Prokinetic: tries to get stuff out of stomachfaster
Causes less absorption of delayed release medications
Epinephrine
Non selective alpha and beta receptor stimulant
- vasoconstriction via alpha 1 receptors
Lasts longer when given with lidocaine