00:08Paracetamol, also known as acetaminophen in some countries, is one of the most widely used
00:13analgesics and antipyretics in the world. It is found in countless homes and is prescribed
00:18or recommended to relieve mild to moderate pain and reduce fever. Its popularity stems
00:24from its accessibility, as it is sold over the counter in many countries, and its relatively
00:29high safety profile when used correctly. However, in a context where self-medication is common,
00:35understanding its recommended dosages is critical to avoid risks such as overdose,
00:39which can lead to serious liver damage. Below, we will explore paracetamol comprehensively,
00:46focusing on its recommended dosages, but also addressing its history, mechanism of action,
00:51indications, side effects, interactions, and overdose management. The history of paracetamol
00:57dates back to the 19th century, when the search for alternatives to existing analgesics fueled
01:02key discoveries in pharmaceutical chemistry. It was first synthesized in 1877 by the German
01:10chemist Karl Moritz Krauser, although its therapeutic potential was not recognized at the time.
01:15A year later, in 1878, the French chemist Harman Northrop Morse synthesized it again,
01:21but it went unnoticed for decades. In 1893, it was identified as a metabolite of finacetine and
01:28acetanolide, compounds used to treat pain and fever, but which proved toxic. The real breakthrough came
01:35in the 1940s, when researchers such as Julius Axelrod and Bernard Brody demonstrated that paracetamol
01:41was the active metabolite responsible for the analgesic effects of these precursors,
01:45but with less toxicity. In 1955, it was launched in the United States under the brand name Tylenol
01:52by McNeil Laboratories, marking its entry into modern medicine. A year later, in 1956, it was introduced
02:00in the United Kingdom as Panadol and quickly spread globally. During the 1970s and 1980s, its use became
02:09popular due to concerns about the risks of aspirin in children, such as Ray's syndrome. However,
02:15incidents such as the 1982 Tylenol mass poisoning in Chicago, where tampered capsules caused deaths,
02:21led to improvements in drug packaging. Today, paracetamol is a mainstay in the global pharmacopoeia,
02:28with strict regulations to prevent overdoses, reflecting its evolution from a forgotten compound
02:33to an essential component in pain management. Paracetamol acts primarily on the central nervous
02:39system, although its exact mechanism remains a subject of study. It is believed to inhibit the
02:44enzyme cyclooxygenase, COX, particularly COX-2 and a variant called COX-3 in the brain,
02:51reducing the synthesis of prostaglandins, which mediate pain and fever. Unlike non-steroidal
02:57anti-inflammatory drugs, NSAIDs, such as ibuprofen, it does not have a significant anti-inflammatory effect,
03:04as its peripheral action is limited. Pharmacologically, it is rapidly absorbed from
03:10the gastrointestinal tract, reaching peak plasma concentrations in 30 to 60 minutes.
03:16Its half-life is approximately 2 to 3 hours in healthy adults, and it is primarily metabolized
03:22in the liver through glucuronide and sulfate conjugation, with a small fraction oxidized
03:26by cytochrome P for 50 to a toxic metabolite, N-acetyl-P-benzoquinonamine, NAPKI. This metabolite
03:34is neutralized by glutathione, but in overdose, it depletes stores and causes liver damage.
03:40Paracetamol readily penetrates the blood-brain barrier, explaining its effectiveness against
03:44central pain and fever. In therapeutic doses, it is safe, but factors such as alcoholism or
03:51malnutrition can alter its metabolism, increasing risks. Recent studies also suggest modulation of
03:57descending serotonergic pathways, blocking nociceptive signals. Paracetamol is primarily
04:03indicated for the symptomatic relief of mild to moderate pain and fever.
04:09It is effective against headaches, muscle aches, toothaches, menstrual pain, and postoperative pain,
04:15as well as in conditions such as osteoarthritis. In pediatrics, it is the drug of choice for fever
04:22and pain in children, especially after vaccinations or viral infections. It is also used in combination
04:28with other medications to treat colds, flu, and migraines. In adults, it is a safe alternative
04:35to NSAIDs for those with gastric ulcers or kidney problems. In hospital settings, its intravenous form
04:42is used for moderate pain and postoperative fever. It is not an anti-inflammatory, so it is not recommended
04:48for acute inflammation such as sprains. Its versatility makes it ideal for all ages,
04:54but always under supervision. In pregnant women, it is considered safe at low doses,
05:00although caution is advised. In short, its use focuses on acute symptoms, not chronic treatments,
05:06to minimize risks. Paracetamol doses should be adjusted according to age, weight, condition,
05:14and individual response, always starting with the lowest effective dose.
05:19In adults and adolescents over 12 years of age weighing more than 50 kg, the typical dose for
05:25pain or fever is 500 mg to 1 g every 4 to 6 hours, not to exceed for g per
05:30day. For rapid relief,
05:33you can start with 1 g, but for persistent pain, divide it into regular doses.
05:38In children, dosage is based on weight for greater accuracy.
05:42For infants and toddlers, 10 to 15 mg per kg of body weight every 6 hours is recommended,
05:49not to exceed 60 mg per kg per day. For example, a 10 kg child could receive 100 to 150
05:57mg per dose,
05:58up to 4 times a day. With liquid formulations, it is crucial to use the dosing device provided to
06:05avoid errors. For special populations, such as the elderly or patients with liver failure,
06:10the dose is reduced to a maximum of 2 g per day, with longer intervals between doses.
06:17For pregnant women, doses should be kept low and short, avoiding exceeding 3 g per day.
06:23For children over 6 years of age, chewable tablets can be used, titrated to 325 mg every 4 to 6
06:31hours.
06:32For intravenous treatments, such as in hospitals, the starting dose for adults is 1 g every 6 hours,
06:38adjusted for weight if less than 50 kg. For children, 5 doses should not be exceeded in 24 hours,
06:46and monitoring is recommended if combined with other products containing paracetamol.
06:51Paracetamol is primarily administered orally in tablets, capsules, suspensions, or suppositories.
06:58It can be taken with or without food, although food reduces gastric irritation.
07:03Liquid forms are ideal for children, and suppositories are recommended for use when vomiting occurs.
07:10Intravenously, it is infused slowly to avoid hypertension.
07:14Drinking plenty of water aids absorption, and avoiding alcohol is key during treatment.
07:21Although generally well-tolerated, paracetamol can rarely cause side effects such as nausea,
07:26vomiting, or skin rashes.
07:29At high or prolonged doses, it increases the risk of liver damage, hypertension, ulcers,
07:34and heart failure, according to recent studies.
07:38Serious reactions include Stevens-Johnson syndrome or jaundice.
07:42It is contraindicated in cases of paracetamol hypersensitivity, severe liver failure, or active hepatitis.
07:50Caution should be exercised in alcoholics, malnourished individuals, or those with kidney failure.
07:56Do not use for fever for more than 3 days without consulting a doctor.
08:00It interacts with warfarin, increasing the risk of bleeding,
08:04and with hepatic induction agents such as carbamazepine, which potentiate its toxicity.
08:10Alcohol worsens liver damage, and avoid multivitamins with paracetamol to avoid double doses.
08:16Overdose occurs in phases, initially nausea and vomiting,
08:20then abdominal pain and jaundice, which can lead to coma or liver failure.
08:26Treatment includes activated charcoal if recently diagnosed,
08:30N-acetylcysteine as an antidote, and hospital support.
08:34Paracetamol is an invaluable ally against pain and fever when dosed correctly,
08:38but misuse can be dangerous.
08:41Prioritize professional consultations and red labels for safe handling.
08:45In a world of self-medication,
08:47knowledge is the best prevention for enjoying its benefits without risks.
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