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wikitox:table_for_si_units

Table for SI Units

NOMOGRAM FOR N-ACETYLCYSTEINE TREATMENT

SI units (micromol/L)

Hours post dose UK/Australia USA Risk factors
413001000650
4.51192917596
51093841547
5.51002771501
6919707460
6.5843648421
7773595386
7.5709545354
8650500325
8.5596459298
9547420273
9.5501386251
10460354230
10.5421324211
11386297193
11.5354273177
12325250162
12.5298229149
13273210137
13.5251193125
14230177115
14.5211162105
1519314997
15.517713689
1616212581
16.514911575
1713710568
17.51259663
181158857
18.51058153
19977448
19.5896844
20816241
20.5755737
21685334
21.5634831
22574429
22.5534126
23483724
23.5443422
24413120

The 3 columns reflect the 3 most commonly used nomogram lines. Although the lines are commonly extrapolated to 24 hours, they have not been validated beyond 16 hours.

Column one reflects Prescott's original data and is widely used in the United Kingdom, Australia and Europe.

Column two reflects the original USA study protocol and is the standard of care in USA.

Column three is not based on any good data, see high risk groups (below).

Either of the UK or USA columns is reasonable to assess risk and need for therapy for most patients, the US line is more aggressive.

Units of measure

Paracetamol (acetaminophen) concentrations are commonly reported in either SI units (micromol/L or mmol/L) or in mass units (mg/L). This can sometimes lead to confusion when interpreting results to assess the risk of hepatotoxicity. Be sure that you know which units your laboratory uses.

High Risk groups

Theoretically toxicity is more likely if the P450 enzymes are induced by chronic alcohol ingestion, anticonvulsants or barbiturates (i.e. more toxic metabolite). Inhibition of P450 enzymes at the time of the overdose may reduce the production of toxic metabolites. This most commonly occurs with acute alcohol ingestion (4-6 drinks) & may also occur with co-ingestions or chronic medication with drugs that inhibit these enzymes (e.g. cimetidine). Patients with depleted glutathione may be at increased risk of toxicity e.g. chronic ingestion of paracetamol, malnutrition & eating disorders.

The nomogram represented by the risk column has been suggested to be used for these patients.


/home/wikitoxo/public_html/data/pages/wikitox/table_for_si_units.txt · Last modified: 2018/09/01 09:01 (external edit)