Parenteral Drug Incompatibilities Flashcards
With IV solutions insoluble particles can lead to what?
adverse effects
potential under treatment
occlusion of infusion lines
possible occlusion of patient capillaries
When a drug is dissolved in a cosolvent system and product diluted with water, the drug will ____
precipitate
When drugs are considered weak electrolytes, the degree of ionization depends on the _____
pH
When there are large differences in the solubilities of the two forms and when a drug that generates a different pH is added to the original drug solution, what may happen?
one or both may come out of solution
What are some drug solutions that have acidic pH’s?
- phenothiazines
- tetracycline HCl
- Ascorbic acid
- glycopyrrolate
- metaraminol bitartrate
- morphine sulfate
What are some drug solutions that have basic pH’s?
- phenytoin Na
- aminophylline
- sodium bicarbonate
- sodium barbiturates
What are some strategies for handing weak electrolyte solutions?
- control the pH by addition of a buffer
- keep drug solutions with incompatible pH’s separate
- for IM injections draw in separate syringes and give in different sites
- for IV give at different times and flush the IV line between injections of the incompatible solutions
- dilute final solution so that the concentration is below the precipitation concentration
Alkaloids are all bases with____ water solubility
poor
Alkaloids include what?
a wide variety of amine drugs of plant origin
- this includes atropine, cocaine, codeine, colchicine, morphine and ephedrine
What are the compounds that typically will cause an alkaloid to precipitate
citrate salts tannins iodide picric acid (mostly this is caused by a precipitation of a base as a result of a change in pH of the solution)
The addition of what will sometimes prevent precipitation?
- alcohol or glycerin
What happens to the solubility of drugs as the temperature decreases?
it also decreases
Refrigeration of drugs is often recommended when we want to ____ stability and ____ microbial growth
increase
retard
What are some examples of parenteral drugs where refrigeration is not recommended due to precipitation?
- fluorouracil
- cisplatin
- cotrimoxazole
- metronidazole
- some brands of aminophylline
Chemical reactions such as ___________ formation can occur and result in drug instability when drugs are mixed together
hydration, decarboxylation, additions and Schiff’s base formation
