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wikitox:table_for_mass_units

Table for Mass Units

NOMOGRAM FOR N-ACETYLCYSTEINE TREATMENT

Mass units (mg/L)

Hours post dose UK/Australia USA Risk factors
4200150100
4.518313890
516812682
5.515411675
614110670
6.51309763
71198958
7.51098253
81007548
8.5916945
9846341
9.5775838
10715334
10.5654931
11604529
11.5554127
12503724
12.5463422
13423221
13.5392919
14352718
14.5322416
15302214
15.5272013
16251912.3
16.5231711
17211610
17.519149
1818138
18.516128
1915117
19.514106
20129
20.5119
21108
21.597
2287
22.586
2376
23.565
2465

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_mass_units.txt · Last modified: 2018/09/01 09:01 (external edit)