Before taking two cold or pain relievers at the same time, check their ingredient lists — only one of them should contain acetaminophen.

1. Before taking two cold or pain relievers at the same time, check their ingredient lists — only one of them should contain acetaminophen.

Cost: No cost at all. It only takes a minute or two to glance at the ingredient list on each package.

In plain terms: Acetaminophen is present in many cold medicines. Taking two such products means you’re consuming double the dose, which can damage the liver. In the U.S., nearly 30% of patients suffering from acute liver failure due to acetaminophen never receive a liver transplant in time. Domestic instructions recommend a maximum daily intake of 2 grams, and alcohol should be avoided while taking this drug.

Benefit: Over six years, 22 U.S. hospitals tracked 662 cases of acute liver failure. Of these, 275 (42%) were caused by acetaminophen; the median dose consumed was 24 grams. Among those 275 patients, 131 (48%) took the drug unintentionally. In 38% of those cases, they were also taking two or more other medications containing acetaminophen. Ultimately, 27% of these patients died before a transplant became possible, while 8% underwent liver transplantation. In 2020, China’s National Medical Products Administration mandated that OTC packaging clearly state excessive use can cause severe liver damage and that the daily limit is 2 grams. Packaging must also warn against combining this drug with other acetaminophen-containing or analgesic products. U.S. regulations require such OTC products to explicitly list three main risk factors: exceeding the daily limit, concurrent use with other acetaminophen-containing drugs, and drinking more than three alcoholic drinks daily while taking it.

Evidence grade: B

Sources: Larson AM, Polson J, Fontana RJ, et al.; Acute Liver Failure Study Group (2005). Acetaminophen-induced acute liver failure: results of a United States multicenter, prospective study. Hepatology, 42(6):1364-1372. <https://doi.org/10.1002/hep.20948>; Announcement of the State Food and Drug Administration on revising the instructions for immediate-release and sustained-release acetaminophen preparations (No. 15, 2020) and Appendix 2 "Revision Requirements for Over-the-Counter Instructions for Acetaminophen Immediate-Release Preparations" (Reprinted by the Hunan Provincial Food and Drug Administration). <http://mpa.hunan.gov.cn/mpa/xxgk/tzgg/wjtz/202003/t20200311_11809335.html>; 21 CFR 201.326(a)(1)(iii)(A) Liver warning. <https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-201/subpart-G/section-201.326>

Notes: Acetaminophen is also known as paracetamol. Cold medicines whose generic names contain the characters “anfen” — such as paracetamol pseudoephedrine or paracetamol caffeine chlorpheniramine — all contain this ingredient. When in doubt, bring all your medications to a pharmacist for review. This evidence grade is set at B because the U.S. data comes from case registries lacking a control group, so it’s impossible to calculate exactly how many adverse events could be prevented by checking ingredient lists. The “large” benefit rating is based on the severity of outcomes: nearly 30% of acute liver failure cases end in death.