PubMed Health⌕ Search

PubMed · 7056022

Acetaminophen kinetics in the elderly.

Abstract

Thirty-two healthy men and women, 23 to 78 yr old, received single 650-mg intravenous doses of acetaminophen and the drug's kinetics were determined from multiple plasma samples drawn over the next 8 to 12 hr. Acetaminophen elimination half-life averaged 2.7 hr (range, 1.9 to 4.3 hr) and was not related to age or sex. Volume of distribution (corrected for weight) was larger in men than in women (0.99 and 0.86 l/kg) and declined with age in both sexes. This probably reflects increased fat per kilogram body weight in women and in the elderly, together with incomplete distribution of this nonlipophilic drug into body fat. Acetaminophen clearance tended to decline with age in both sexes, but differences were of borderline significance. On the basis of kinetics data alone, adjustment of acetaminophen dosage for the elderly is generally not necessary.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Divoll, D R Abernethy, B Ameer, D J Greenblatt. 1982. Acetaminophen kinetics in the elderly.. https://doi.org/10.1038/clpt.1982.24

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

[Evaluation of postoperative analgesia with continuous iliofascial nerve sheath block after total hip arthroplasty replacement: a pilot study].

OBJECTIVE: To assess the analgesic efficiency of a continuous iliofascial nerve sheath block after total hip arthroplasty replacement (RPTH). STUDY DESIGN: open and prospective pilot study. PATIENTS AND METHODS: Before induction of general anaesthesia (GA), an iliofascial catheter was inserted (group KT, n = 11) or not (group NKT, n = 10). In the KT group, 30 ml of ropivacaïne 4,75 mg/ml (maximum dose) were injected, and 14 mg/h of ropivacaïne 2 mg/ml were infused during the first 48 postoperative hours. All patients underwent a standardized GA and a multimodal postoperative analgesia with a intravenous PCA morphine, paracetamol and tramadol during the first 48 hours. Postoperative pain assessment which was achieved using visual analogic scores (VAS) at rest (EVAr) and on movement (EVAm), total morphine consumption, and side effects were collected during the first 48 hours. Statistical analysis was performed using a Mann and Whitney test for the quantitative values and a chi 2 exact test for the qualitative values. Data are expressed as median [interquartile range]. RESULTS: Total morphine consumption was lower in the KT group with a total amount of 26 mg [11-48] versus 77.5 mg [55-91] (p = 0.007) at h48. EVAr and EVAm were lower in the KT group at h4, h8, h24, h36 for the EVAr and during the 48 postoperative hours for EVAm. Three patients experienced nausea and/or vomiting in the KT group versus 6 in the NKT group (p = 0.05). CONCLUSION: After RPTH surgery, continuous iliofascial block reduces morphine consumption; provide a better pain relief at rest and on movement than IV multimodal analgesia alone.

Acetaminophen↗

Aquatic toxicity of acetaminophen, carbamazepine, cimetidine, diltiazem and six major sulfonamides, and their potential ecological risks in Korea.

Pharmaceuticals are manufactured and used for specific biological functions in veterinary and human medicine. Their detection in the environment and their bioactivity have resulted in concern for potential adverse effects on non-target species. Notwithstanding recent attention for their occurrence in the environment, there are significant research gaps for existing pharmaceuticals with regard to their potential ecological consequences. In this study, the four most abundantly used pharmaceuticals in Korea, namely acetaminophen, carbamazepine, cimetidine, and diltiazem, and six sulfonamide related antibiotics, including sulfamethoxazole, sulfachlorpyridazine, sulfathiazole, sulfamethazine, sulfadimethoxine, and trimethoprim were examined for their acute aquatic toxicity employing a marine bacterium (Vibrio fischeri), a freshwater invertebrate (Daphnia magna), and the Japanese medaka fish (Oryzias latipes). In general, Daphnia was the most susceptible among the test organisms. The most acutely toxic among the chemicals tested in this study was diltiazem, with a median lethal concentration of 8.2 mg/L for D. magna. The resulting acute toxicity of these pharmaceuticals was reasonably predicted by physicochemical descriptors such as pH-dependent distribution coefficient and EHOMO-ELUMO gap. Predicted environmental concentrations (PECs) derived for the test pharmaceuticals in Korea ranged between 0.14 and 16.5 microg/L. Hazard quotients derived from PECs and predicted no effect concentrations (PNECs) for sulfamethoxazole and acetaminophen were 6.3 and 1.8, respectively, suggesting potential environmental concerns and a need for further investigation.

Acetaminophen↗

The effect of acetaminophen on the crystal growth of calcium carbonate.

The effect of acetaminophen, a well known analgesic and fever-reducing medicine, on the calcium carbonate crystal growth was investigated under plethostatic conditions. The calcification rates measured was reduced by 9.1-63.2% in the presence of acetaminophen. Kinetic analysis according to a Langmuir-type adsorption isotherm lead to the calculation of an affinity constant K (aff) = 8.33 x 10(2 )dm(3 )mol(-1). The apparent order found from kinetic data was two suggesting a surface diffusion controlled spiral growth mechanism.

Acetaminophen↗