Blood Testing for Digoxin/Frusemide with Limited funds?

RE: Blood Testing for Digoxin/Frusemide with Limited funds?

Anthony Todd — Mon, 28 Sep 2015 22:33:19 GMT

In humans
Therapeutic levels are 0.6-1.3 to 2.6 ng/mL
levels associated with toxicity overlap between therapeutic and toxic ranges
From:
http://emedicine.medscape.com/article/154336-overview

Sounds like it might be better to watch for the toxic signs rather than watch blood levels?

RE: Blood Testing for Digoxin/Frusemide with Limited funds?

Anthony Todd — Mon, 28 Sep 2015 22:19:53 GMT

[quote user="Aine Seavers"]I dont have enough experience to advise you as didnt do enough of plain digoxin dogs before the acei hit the scene but there must be some on this list who can share their knowledge and treat for the treatable in this case.[/quote]

Yes, I too wonder if there is any comparative studies on the reliability of clinical signs of toxicity and digoxin blood levels.

[see previous thread on barbiturates and epilepsy]

RE: Blood Testing for Digoxin/Frusemide with Limited funds?

Aine Seavers — Mon, 28 Sep 2015 12:56:04 GMT

so in the absence of funds and in the presence of a dying dog-what therapy have you discussed with the client to assist the dog? Just watching a program on medical system here where 90% of testingin some conditions a waste of time- was quite shocked by that and about how many stents should be instead drug therapy,So if not going the testing route- what treatment route? There must be a pleotheora of vets on this list who once a upon a time only had digoxin and lasix to use as heart meds and mostly without testing-how did they treat these cases-did they start the drugm advise the client at the first sign of vomiting to stop and resume at 50% of original dose after 2 days and did they then get dogs live many years on said regime-not a perfect regime but in the face of not having the money to test- then mining the tacit knowledges of vets who used these drugs extensively might help this dog. I dont have enough experience to advise you as didnt do enough of plain digoxin dogs before the acei hit the scene but there must be some on this list who can share their knowledge and treat for the treatable in this case.

RE: Blood Testing for Digoxin/Frusemide with Limited funds?

Yvonne McGrotty — Fri, 25 Sep 2015 11:51:15 GMT

Hopefully when SDMA (symmetrical dimethylarginine) becomes available next year via IDEXX, some of the uncertainty surrounding renal dysfunction may be somewhat clearer in many of these patients. Recent studies have shown that SDMA identified kidney disease much earlier than creatinine alone. SDMA increases on average with 40% loss of kidney function versus creatinine which does not increase til 75% of kidney function is lost. Using SDMA to 'screen' these animals (alongside standard renal parameters) pre-treatment may help to identify cases which will be more at risk of further decline in renal function.

The use of frusemide can cause azotaemia but this may be prerenal (although this is difficult to confirm since frusemide will also result in more dilute urine SG). SDMA may once again assist in these cases.

As for measuring digoxin levels.....I would definitely recommend it where possible. Digoxin toxicity can be fatal and can result in further arrhythmias, GI signs or even seizures. Some animals can develop such signs even when digoxin is prescribed at recommended doses so its worth knowing if you are approaching potential toxic levels.

When funds are limited, often clinical judgement is the best tool to assist you in deciding which cases should be monitored more closely.

Best wishes

Yvonne

RE: Blood Testing for Digoxin/Frusemide with Limited funds?

David Mills — Tue, 22 Sep 2015 22:32:42 GMT

Charity viewpoint, I don't monitor renal values or electrolytes in CHF being treated with furosemide. This goes for dogs with CHF without AF. You can, but I have found (when I used to test) that very few develop clinically significant renal issues. Dogs with CHF and AF rarely last long (usually <3 months) so the CHF/AF will kill them quicker than renal issues. Also the digoxin serum levels correspond very poorly to therapeutic effect.

I also don't worry about not using a ACEi with furosemide. The thinking behind it is based on opinion, mechanistic reasonining and exerimental studies, and has no evidence in improving survival, or worsening renal function if you don't use ACEi.

As an aside, digoxin and diltiazem combination has been shown to control rate better than digoxin alone. If money is tight, this may be a better route to take? Diltiazem *may* have beneficial effects on renal perfusion also.

http://www.ncbi.nlm.nih.gov/pubmed/19645836