Toxic interaction of didanosine and acetaminophen leading to severe hepatitis and pancreatitis: a case report and review of the literature

Acetaminophen-induced acute pancreatitis: A case report and literature review

Acute pancreatitis is rarely associated with drugs. Acetaminophen overdose is a well-known cause of hepatic toxicity, but drug-induced pancreatitis is rarely reported, especially after mild overdose. A 32-year-old woman presented with nausea and vomiting for 12 h, but no abdominal pain following an overdose of eight Tylenol tablets containing acetaminophen (325 mg acetaminophen per tablet). Laboratory results on admission showed abnormal amylase and lipase levels but completely normal liver function. Magnetic resonance cholangiopancreatography revealed mild swelling of the pancreas without fluid collection around the pancreas. The patient complained of severe abdominal pain five days after admission when attempting to drink water and liquids. Eight days after admission, fluid around the pancreas was observed by computed tomography. The patient was subsequently diagnosed with acetaminophen-induced acute pancreatitis after exclusion of common causes. Routine treatment for pancreatitis and N-acetylcysteine were administered to prevent disease progression. The patient was discharged in good condition.

The purine analogues abacavir and didanosine increase acetaminophen-induced hepatotoxicity by enhancing mitochondrial dysfunction

BACKGROUND

NRTIs are essential components of HIV therapy with well-documented, long-term mitochondrial toxicity in hepatic cells, but whose acute effects on mitochondria are unclear. As acetaminophen-induced hepatotoxicity also involves mitochondrial interference, we hypothesized that it would be exacerbated in the context of ART.

METHODS

We evaluated the acute effects of clinically relevant concentrations of the most widely used NRTIs, alone or combined with acetaminophen, on mitochondrial function and cellular viability.

RESULTS

The purine analogues abacavir and didanosine produced an immediate and concentration-dependent inhibition of oxygen consumption and complex I and III activity. This inhibition was accompanied by an undermining of mitochondrial function, with increased production of reactive oxygen species and reduction of mitochondrial membrane potential and intracellular ATP levels. However, this interference did not compromise cell survival. Co-administration with concentrations of acetaminophen below those considered hepatotoxic exacerbated the deleterious effects of both compounds on mitochondrial function and compromised cellular viability, showing a clear correlation with diminished glutathione levels.

CONCLUSIONS

The simultaneous presence of purine analogues and low concentrations of acetaminophen significantly potentiates mitochondrial dysfunction, increasing the risk of liver injury. This new mechanism is relevant given the liver's susceptibility to mitochondrial dysfunction-related toxicity and the tendency of the HIV infection to increase oxidative stress.

Acetaminophen receipt among HIV-infected patients with advanced hepatic fibrosis

PURPOSE

HIV-infected patients may be at particular risk for acetaminophen-induced hepatotoxicity, but acetaminophen use in the context of liver injury has been incompletely examined among HIV-infected patients. Among a sample of HIV-infected patients, we aimed to determine acetaminophen exposure, assess the cross-sectional association between acetaminophen exposure and advanced hepatic fibrosis, and determine whether factors associated with acetaminophen exposure varied by HCV status.

METHODS

We conducted a cross-sectional analysis of the Veterans Aging Cohort Study. Advanced hepatic fibrosis was defined as a FIB-4 > 3.25, a composite score calculated based on age, alanine aminotransferase, aspartate aminotransferase, and platelet count. Multivariable ordered polytomous logistic regression was used to determine the association between FIB-4 status and acetaminophen exposure stratified by HCV status.

RESULTS

Among HIV-infected patients (n = 14 885), 31% received at least one acetaminophen prescription. Among those receiving acetaminophen, acetaminophen overuse was common among both HIV-monoinfected and HIV/HCV-coinfected patients (846 [31%] vs 596[32%], p = 0.79). After stratifying by HCV status, those with evidence of advanced liver fibrosis were equally likely to be exposed to acetaminophen. Furthermore, HIV-monoinfected patients with an alcohol use disorder were more likely to have acetaminophen overuse (OR [95%CI] = 1.56 [1.21-2.02]).

CONCLUSIONS

Strategies to minimize acetaminophen exposure, especially for HIV-monoinfected patients, are warranted.

Does therapeutic use of acetaminophen cause acute liver failure?

STUDY OBJECTIVE

To compare the reported occurrence of liver failure in subjects in prospective trials with that in patients in retrospective reports after repeated use of therapeutic dosages of acetaminophen.

DESIGN

Systematic review of the medical literature.

DATA SOURCE

MEDLINE and EMBASE biomedical and pharmacologic databases.

SUBJECTS

Adults who received repeated dosing of acetaminophen 4 g/day or lower for at least 24 hours.

MEASUREMENTS AND MAIN RESULTS

Articles written in several languages were abstracted by trained personnel using a structured abstraction form. Data were categorized by methodology (prospective vs retrospective), acetaminophen dosage, and type of liver effect. A total of 791 articles were identified, which included 30,865 subjects in prospective studies and 9337 patients in retrospective reports. The prospective studies reported no cases of fulminant hepatic injury, liver transplantation, or death due to acetaminophen. Of the 30,865 subjects in these studies, 129 (0.4%) were identified who had a serum aminotransferase level that exceeded the upper limit of normal, including 61 subjects in randomized trials in which the proportion of serum aminotransferase level increase was the same as or less than that in the placebo group and 68 subjects in trials without a placebo group. In addition, 4263 (13.8%) received the maximum recommended therapeutic dosage (3.9-4 g/day). In the retrospective reports, 96 patients (1.0%) had a serum alanine aminotransferase level that exceeded the upper limit of normal, one (0.01%) underwent liver transplantation, and six (0.06%) died. Causality relationship of acetaminophen for each retrospective case was assessed with the Naranjo adverse drug reaction probability scale. The mean +/- SD Naranjo score for all 103 retrospective cases was 3.2 +/- 1.9, indicating a possible relationship between the increased aminotransferase levels and acetaminophen use. Some retrospective reports contained information suggesting that the patient had ingested an overdose despite a history of therapeutic use.

CONCLUSION

Prospective studies indicated that repeated use of a true therapeutic acetaminophen dosage may slightly increase the level of serum aminotransferase activity, but hepatic failure or death was not reported. Retrospective reports indicated a higher rate of increased serum aminotransferase levels, and several reported associated liver injury and death. The differing results and presence of evidence indicating inaccurate acetaminophen dosage information in some case reports suggests that these cases may be inadvertent overdoses, rather than true therapeutic dosages.

Lower rate of preeclampsia after antioxidant supplementation in pregnant women with low antioxidant status

OBJECTIVE

To investigate maternal and neonatal outcomes after antioxidant supplementation relatively early in pregnancy (8 to 12 weeks) for pregnant women with low antioxidant status.

METHODS

A randomized, double-blind, placebo-controlled trial of daily antioxidant supplementation was performed on pregnant women screening positive for low antioxidant status at 8 to 12 weeks of gestation. Low antioxidant status was defined as a superoxidedismutase (SOD) level below 1102 U/g Hb or 164 U/mL. The supplementation group received the following antioxidants daily: vitamins A (1000 IU), B6 (2.2 mg), B12 (2.2 microg), C (200 mg), and E (400 IU), folic acid (400 microg), N-acetylcysteine (200 mg), Cu (2 mg), Zn (15 mg), Mn (0.5 mg), Fe (30 mg), calcium (800 mg), and selenium (100 microg). The control group received Fe (30 mg) and folic acid (400 microg). Maternal (preeclampsia, abortion, and hypertension) and perinatal outcomes were assessed.

RESULTS

In the supplementation group (29 subjects), we observed 2 cases of preeclampsia (6.8%, 1 mild and 1 severe), 1 of IUGR (birth weight 2300 g at 38 weeks), and 1 preterm delivery. In the control group (31 subjects), there were 8 abortions, 9 cases of preeclampsia (29%, 6 mild and 3 severe) with perinatal outcome: 3 preterm delivery cases and 1 IUGR (birth weight 2030 g at 39 weeks). Preeclampsia was significantly less frequent in the supplementation group when compared to the control group (2 vs. 9 cases, p = 0.043, OR = 0.18 [95% CI: 0.03, 0.92]). Finally we focused on the prediction of preeclampsia at 8 to 12 weeks. Combined sensitivity of markers of antioxidant status (SOD slutathione peroxidase, [GPx], and total anti-oxidant status [TAS]) was 33% (false-positive rate of 4.5%).

CONCLUSION

Antioxidant supplementation was associated with better maternal and perinatal outcome in pregnant women with low antioxidant status than control supplementation with iron and folate alone. In a selected population already screened positive for low SOD, preeclampsia can be detected in 33% of asymptomatic cases in the first trimester using SOD, GPx, and TAS. It seems feasible that panels of both biochemical and molecular markers may be clinically useful in the prediction of this disease.

A review of the common properties of drugs with idiosyncratic hepatotoxicity and the "multiple determinant hypothesis" for the manifestation of idiosyncratic drug toxicity

Idiosyncratic drug toxicity is generally believed to be a phenomenon that cannot be readily evaluated experimentally. Reasons for this difficulty include the following: 1. It is a rare event (<1/5,000) and therefore impossible to be studied in clinical trials; 2. It is a human-specific event not detectable in experimental animals. To aid the understanding of idiosyncratic toxicity and to develop an experimental strategy for this phenomenon, a hypothesis is proposed. The hypothesis states that the low frequency of idiosyncratic drug toxicity is due to the requirements for the occurrence of multiple critical and discrete events, with the probability for the occurrence of idiosyncratic drug toxicity as a product of the probabilities of each event. The key determinants of these critical events are proposed to be: 1. Chemical properties; 2. exposure; 3. environmental factors; and 4. genetic factors. Based on this hypothesis, idiosyncratic drug toxicity can be evaluated experimentally via studying these key determinants. The chemical properties critical to idiosyncratic drug toxicity are identified via a review of the common properties of drugs that cause idiosyncratic liver toxicity. These properties include: 1. Formation of reactive metabolites. 2. Metabolism by P450 isoforms. 3. Preponderance of P450 inducers, and 4. Occurrence of clinically significant pharmacokinetic interactions with co-administered drugs. Based on this review, it is proposed that these common properties may be useful experimental endpoints for the prediction and therefore avoidance of the selection of drug candidates with idiosyncratic drug toxicity for further development.