Can an early diagnostic procedure of metformin-associated lactic acidosis in an emergency unit reduce mortality?

OBJECTIVE: Metformin-associated lactic acidosis (MALA) is a rare but serious adverse reaction with a mortality rate of up to 50%. Unfortunately, diagnosis and care management are often delayed. The objective was to assess the impact on the mortality rate and length of hospital stay of a MALA early diagnosis procedure in diabetic patients with metformin at emergency department (ED) admission. METHOD: From 1/7/2012, a new MALA diagnosis procedure (pH, lactate, metformin) was implemented in all diabetic patients with metformin just after their admission to the ED. The pharmacovigilance staff confirmed the MALA cases (defined as pH≤7.35, lactate concentration>5mmol/L) in patients exposed to metformin and after a causality assessment to eliminate other common causes of lactic acidosis. To assess the impact of this new diagnosis procedure, a before-after study was conducted between two groups: a series of cases with intervention (IG; 1/7/2012-30/6/2013) and a control series of past cases without intervention (CG; 1/1/2011-30/6/2012). The main outcome was the relative reduction of mortality rate and length of hospital stay between the two groups. RESULTS: Thirty-four MALA cases were confirmed in 745 subjects admitted with lactic acidosis, (IG: 12; CG: 22). A higher illness severity score in the IG vs. CG was observed: respectively arterial lactate (14.2±6.9 vs. 8.8±5.8mmol/L, P<0.05), arterial bicarbonate (7.8±4.3 vs. 14.3±6.3mmol/L, P<0.05). The median time up to MALA diagnosis was 20.5 (Q1-Q3: 11.3-38.5) minutes for IG and 55.0 (Q1-Q3: 33.0-132.0) minutes for CG. After procedure implementation, the mortality relative risk reduction was 26.7% (95% CI: -84.3%, 70.8%), and especially 54.2% (95% CI: -265.2%, 94.2%) in the ED. There was no difference in the hospital stay duration between the two groups. CONCLUSION: While the results were not significant, the study suggests that the implementation of a MALA early diagnosis procedure in all patients with metformin admitted to an ED tends to decrease mortality, especially for serious MALA cases detected earlier.

Is inappropriate medication use a major cause of adverse drug reactions in the elderly?

AIM: To study the occurrence of adverse drug reactions (ADRs) linked to inappropriate medication (IM) use in elderly people admitted to an acute medical geriatric unit. METHODS: All the elderly people aged > or = 70 years admitted to the acute medical geriatric unit of Limoges University hospital (France) over a 49-month period were included, whatever their medical condition. For all the patients, clinical pharmacologists listed the medications given before admission and identified the possible ADRs. The appropriateness of these medications and the causal relationship between drugs (either appropriate or not) and ADRs were evaluated. RESULTS: Two thousand and eighteen patients were included. The number of drugs taken was 7.3 +/- 3.0 in the patients with ADRs and 6.0 +/- 3.0 in those without ADRs (P < 0.0001). Sixty-six percent of the patients were given at least one IM prior to admission. ADR prevalence was 20.4% among the 1331 patients using IMs and 16.4% among those using only appropriate drugs (P < 0.03). In only 79 of the 1331 IM users (5.9%) were ADRs directly attributable to IMs. The IMs most often involved in patients with ADRs were: anticholinergic antidepressants, cerebral vasodilators, long-acting benzodiazepines and concomitant use of two or more psychotropic drugs from the same therapeutic class. Using multivariate analysis, after adjusting for confounding factors, IM use was not associated with a significant increased risk of ADRs (odds ratio 1.0, 95% confidence interval 0.8, 1.3). CONCLUSION: Besides a reduction in the number of drugs given to the elderly, a good prescription should involve a reduction in the proportion of IMs and should take into consideration the frailty of these patients.

Impact of hospitalisation in an acute medical geriatric unit on potentially inappropriate medication use.

BACKGROUND AND OBJECTIVE: Potentially inappropriate medication use is a major safety issue in the elderly and may cause a substantial proportion of drug-related hospital admissions. Hospitalisation could result in a change in the quantity and type of drugs, but its effect on potentially inappropriate drug use is still unknown. The aim of this study was to estimate the potentially inappropriate medication prevalence in patients > or =70 years of age at admission to and at discharge from an acute medical geriatric unit, and to identify the factors associated with no longer being a potentially inappropriate drug user at hospital discharge. METHODS: A prospective drug surveillance study was undertaken in 2018 elderly patients (> or =70 years of age) admitted to an acute medical geriatric unit in Limoges University Hospital, France. Prescribing patterns were established at admission and at discharge. Potentially inappropriate medication use was evaluated according to a list derived from the Beers criteria and adapted to French practice. "To be no longer a potentially inappropriate drug user at discharge" was defined as using at least one potentially inappropriate medication at admission and not using it at discharge. RESULTS: The numbers of drugs used at admission/discharge were 6.2 +/- 3.1/5.4 +/- 2.5. The prevalence of potentially inappropriate medication use decreased from 66% (95% CI 63.8, 68.0) at admission to 43.6% (95% CI 41.3, 45.9) at discharge. At discharge, 535 subjects were no longer potentially inappropriate medication users. Multivariate analysis showed that no longer being a potentially inappropriate medication user was associated with the number of drugs used (4-6 drugs vs < or =3 odds ratio [OR] 1.20; 95% CI 0.86, 1.68; 7-9 drugs vs < or =3 OR 1.37; 95% CI 0.97, 1.93; > or =10 drugs vs < or =3 OR 1.64; 95% CI 1.10, 2.44), age (80-89 years vs 70-79 years OR 1.38; 95% CI 1.03, 1.85; > or =90 years vs 70-79 years OR 1.69; 95% CI 1.22, 2.83), cerebral vasodilator use (OR 2.87; 95% CI 2.31, 3.57), analgesic use (OR 1.54; 95% CI 1.06, 2.25) and concomitant use of psychotropic drugs of the same therapeutic class (OR 1.94; 95% CI 1.29, 2.92). CONCLUSION: Hospitalisation in geriatric services results in a reduction in potentially inappropriate medication use. Improved pharmacological education of practitioners, especially with regard to drug adverse effects, is desirable to improve management of geriatric patients.