Making appointments for Drug blood levels, the effects of drugs and
screening tests
Drug levels Effects of Drugs
Screening
Tests
Drug blood levels
Some drugs need to be monitored to ensure they are having an optimal effect
in the patient. as a results we need to take bloods at a specific time to obtain
meaningful information.
So when should you make your appointment to measure
certain drug levels?
We aim to measure trough levels of drugs, logically this occurs just
before the next due dose. However when multiple drugs are given and both
need monitoring then the best time is just before the next combo dose (as this
will be a dual trough level).
EXAMPLES:
Phenobarbitone: just before next dose
Bromide: just before next dose
Phenobarbitone and bromide: bloods just before next bromide/phenobarb combo dose
Gemfibrozil (lopid) and bromide: just before the next combo dose.
Thyroxine (given as a medicine): just before next due dose
Effects of Drugs on blood levels
Insulin: effect on Glucose
We are trying to measure trough blood glucose levels, so bloods at 6 hours post
insulin injection. Advice: Client feeds am, injects insulin, and no further
feeding til bloods done 6 hrs later.
Neomercazole: Effect on T4
We are trying to see how low neomercazole drags the T4 level. Usually therefore
measure at maximum effect of neomercazole. Neomercazole is ideally given 8
hourly so max effect = 4 hours. Thus bloods at 4 hours post neomercazole.
Screening Tests
There are 2 main screening tests performed at Seaforth Vets, both for the
detection and monitoring of Cushings and Addison's Disease. (i.e. adrenal gland
disease)
ACTH Stimulation: takes 1 hour only. So can be done any time of day up
to 5pm say. Animal needs dropping off. However best not fed 12 hours before any
bloods so morning is easiest on the animal.
Dexamethasone screening: Takes 8 hours, so the animal MUST be dropped
off by 10 am at latest to fit the test into the day. Again starve over night for
best results.
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