therapeutic range

[sueeyre]

therapeutic range and i need to explain the significance of this when calculating the dose to the patient

[LeftArm]

The therapeutic range is the level of drug in the blood great enough to provide the required therapeutic response but small enough to restrict the possibility of side effects.

Drugs with a short half life will need to be taken more often to keep them within the therapeutic range. Eg Amoxicillin has a short half life and limited side effect so a largish dose is taken at regular intervals so the levels are "topped up" before the drug is metabolised. It has a wide therapeutic range. Warfarin has a lot of potential side effects but also remains in the blood stream longer. The therapeutic range is much smaller so doses have to be very carefully monitored to keep drug levels within the therapeutic range.

[johnep]

Classic example of a med with very narrow range is IV Heparin. One reason why substantially replaced by LMW heparins.
johnep

[bobbin]

Classic example of a med with very narrow range is IV Heparin. One reason why substantially replaced by LMW heparins.
johnep

Other examples are lithium, digoxin and theophylline. Blood levels are also potentially useful for nortriptyline, but not commonly performed.