The use of acetaminophen (paracetamol) is generally considered safe for most patients when taken at recommended doses. However, it is contraindicated in certain conditions, most notably severe hepatic impairment.

- Severe hepatic impairment: Acetaminophen is primarily metabolized by the liver. In cases of severe liver disease, the liver’s ability to process acetaminophen safely is significantly reduced, increasing the risk of drug accumulation and toxicity. This can lead to fatal hepatotoxicity even at standard doses. Therefore, acetaminophen is contraindicated in patients with severe hepatic impairment.

- Chronic kidney disease: While caution is advised when using acetaminophen in patients with renal impairment, it is not an absolute contraindication. Dose adjustments or careful monitoring may be necessary, but acetaminophen remains preferable to other analgesics such as NSAIDs, which have more nephrotoxic potential.

- Controlled hypertension: Acetaminophen does not generally affect blood pressure and is considered safe in patients with well-controlled hypertension.

- Mild asthma: Acetaminophen is typically safe and is often recommended over NSAIDs, which can exacerbate asthma symptoms in susceptible individuals.

In summary, the key point is that acetaminophen is contraindicated in severe hepatic impairment due to the risk of hepatotoxicity.

Reference: Goodman & Gilman’s The Pharmacological Basis of Therapeutics, 13th Edition, Chapter 20 / Page 499