Paracetamol relieves pain without causing drowsiness due to central nervous system targeting

Recreational drug use. https://en.wikipedia.org/wiki/Recreational_drug_use

Analgesic drugs act in various ways on the peripheral and central nervous systems; they include paracetamol (also known in the US as acetaminophen), the nonsteroidal Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an intoxicating effect. Recreational drugs are commonly divided into three categories: depressants (drugs that slow down the central nervous system), stimulants (d Analgesics (also known as "painkillers") are used to relieve pain (achieve analgesia). The word analgesic derives from Greek "αν-" (an-, "without") and "άλγος" (álgos, "pain"). Analgesic drugs act in various ways on the peripheral and central nervous systems; they include paracetamol (also known in the US as acetaminophen), the nonsteroidal anti-inflammatory drugs (NSAIDs) such as the salicylates (e.g. aspirin), and opioid drugs such as hydrocodone, codeine, heroin and oxycodone. Some further examples of the brand name prescription opiates and opioid analgesics that may be used recreationally include Vicodin, Lortab, Norco (hydrocodone), Avinza, Kapanol (morphine), Opana, Paramorphan (oxymorphone), Dilaudid, Palladone (hydromorphone), and OxyContin (oxycodone). Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an intoxicating effect. Recreational drugs are commonly divided into three categories: depressants (drugs that slow down the central nervous system), stimulants (drugs that speed up the central nervous system), and hallucinogens (drugs that induce perceptual distortions). In popular practice, recreational drug use is generally tolerated as a social behaviour, rather than perceived as the medical condition of self-medication. A potent central nervous system stimulant, in the 1940s and 50s methamphetamine was used by Axis and Allied troops in World War II, and, later on, other armies, and by Japanese factory workers. It increases muscle strength and fatigue resistance and improves reaction time. Methamphetamine use can be neurotoxic, which means it damages dopamine neurons. As a result of this brain damage, chronic use can lead to post acute withdrawal syndrome. Caffeine: Often found in coffee, black tea, energy drinks, some soft drinks (e.g., Coca-Cola, Pepsi, and Mountain Dew, among others), and chocolate. It is the world's most widely consumed psychoactive drug, but has only mild dependence liability for long-term users. Cannabis: Its common forms include marijuana and hashish, which are smoked, vaporized or eaten. It contains at least 85 cannabinoids. The primary psychoactive component is THC, which mimics the neurotransmitter anandamide, named after the Sanskrit word ananda meaning "joy, bliss, delight". When cannabis is eaten, THC is metabolized into 11-OH-THC; this molecule is the primary psychoactive compound of edible forms of cannabis. THC and 11-OH-THC are partial agonist at But LSD is unique because it is also a partial agonist of dopamine and norepinephrine receptors, particularly the D2R subtypes. LSD (d-Lysergic Acid Diethylamide) is a molecule of the lysergamide family, a subclass of the tryptamine family. In the 1950s, it was used in psychological therapy, and, covertly, by the CIA in Project MKULTRA, in which the drug was administered to unwitting US and Canadian citizens. It played a central role in 1960s 'counter-culture', and was banned in October 1968 by US President Lyndon B Johnson. When these are used, effects may include anxiolysis (reduction of anxiety), analgesia (pain relief), sedation, somnolence, cognitive/memory impairment, dissociation, muscle relaxation, lowered blood pressure/heart rate, respiratory depression, anesthesia, and anticonvulsant effects. Depressants exert their effects through a number of different pharmacological mechanisms, the most prominent of which include potentiation of GABA or opioid activity, and inhibition of adrenergic, histamine or acetylcholine activity. Some are also capable of inducing feelings of euphoria. The most widely used depressant by far is alcohol (i.e. ethanol). Stimulants are also occasionally called "uppers". Depressants or "downers", which decrease mental or physical function, are in stark contrast to stimulants and are considered to be their functional opposites. Stimulants enhance the activity of the central and peripheral nervous systems. Common effects may include increased alertness, awareness, wakefulness, endurance, productivity, and motivation, arousal, locomotion, heart rate, and blood pressure, and a diminished desire for food and sleep. Use of stimulants may cause the body to significantly reduce its production of endogenous compounds that fulfill similar functions. Opium: This "drug derived from the unripe seed-pods of the opium poppy…produces drowsiness and euphoria and reduces pain. Morphine and codeine are opium derivatives." Opioids have led to many deaths in the United States, particularly by causing respiratory depression. === Hallucinogens === Hallucinogens can be divided into three broad categories: psychedelics, dissociatives, and deliriants. They can cause subjective changes in perception, thought, emotion and consciousness. Some inhalant users are injured due to the harmful effects of the solvents or gases, or due to other chemicals used in the products inhaled. As with any recreational drug, users can be injured due to dangerous behavior while they are intoxicated, such as driving under the influence. Computer cleaning dusters are dangerous to inhale, because the gases expand and cool rapidly upon being sprayed. In many cases, users have died from hypoxia (lack of oxygen), pneumonia, cardiac failure or arrest, or aspiration of vomit.

The efficacy and safety of paracetamol for pain relief: an overview of systematic reviews.. 2021. https://doi.org/10.5694/mja2.50992

To evaluate the efficacy and safety of paracetamol as an analgesic medication in a range of painful conditions. Systematic review of systematic reviews of the analgesic effects of paracetamol in randomised, placebo-controlled trials. Conduct of systematic reviews was assessed with AMSTAR-2; confidence in effect estimates (quality of evidence) was assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. MEDLINE, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews; systematic reviews published 1 January 2010 - 30 April 2020. We extracted pain and adverse events outcomes from 36 systematic reviews that assessed the efficacy of paracetamol in 44 painful conditions. Continuous pain outcomes were expressed as mean differences (MDs; standardised 0-10-point scale); dichotomous outcomes were expressed as risk ratios (RRs). There is high quality evidence that paracetamol provides modest pain relief for people with knee or hip osteoarthritis (MD, -0.3 points; 95% CI, -0.6 to -0.1 points) and after craniotomy (MD, -0.8 points; 95% CI, -1.4 to -0.2 points); there is moderate quality evidence for its efficacy in tension-type headache (pain-free at 2 hours: RR, 1.3; 95% CI, 1.1-1.4) and perineal pain soon after childbirth (patients experiencing 50% pain relief: RR, 2.4; 95% CI, 1.5-3.8). There is high quality evidence that paracetamol is not effective for relieving acute low back pain (MD, 0.2 points; 95% CI, -0.1 to 0.4 points). Evidence regarding efficacy in other conditions was of low or very low quality. Frequency of adverse events was generally similar for people receiving placebo or paracetamol, except that transient elevation of blood liver enzyme levels was more frequent during repeated administration of paracetamol to patients with spinal pain (RR, 3.8; 95% CI, 1.9-7.4). For most conditions, evidence regarding the effectiveness of paracetamol is insufficient for drawing firm conclusions. Evidence for its efficacy in four conditions was moderate to strong, and there is strong evidence that paracetamol is not effective for reducing acute low back pain. Investigations that evaluate more typical dosing regimens are required. CRD42015029282 (prospective).

Paracetamol (acetaminophen): A familiar drug with an unexplained mechanism of action.. 2021. https://doi.org/10.1080/23328940.2021.1886392

Paracetamol (acetaminophen) is undoubtedly one of the most widely used drugs worldwide. As an over-the-counter medication, paracetamol is the standard and first-line treatment for fever and acute pain and is believed to remain so for many years to come. Despite being in clinical use for over a century, the precise mechanism of action of this familiar drug remains a mystery. The oldest and most prevailing theory on the mechanism of analgesic and antipyretic actions of paracetamol relates to the inhibition of CNS cyclooxygenase (COX) enzyme activities, with conflicting views on the COX isoenzyme/variant targeted by paracetamol and on the nature of the molecular interactions with these enzymes. Paracetamol has been proposed to selectively inhibit COX-2 by working as a reducing agent, despite the fact that <i>in vitro</i> screens demonstrate low potency on the inhibition of COX-1 and COX-2. <i>In vivo</i> data from COX-1 transgenic mice suggest that paracetamol works through inhibition of a COX-1 variant enzyme to mediate its analgesic and particularly thermoregulatory actions (antipyresis and hypothermia). A separate line of research provides evidence on potentiation of the descending inhibitory serotonergic pathway to mediate the analgesic action of paracetamol, but with no evidence of binding to serotonergic molecules. AM404 as a metabolite for paracetamol has been proposed to activate the endocannabinoid and the transient receptor potential vanilloid-1 (TRPV1) systems. The current review gives an update and in some cases challenges the different theories on the pharmacology of paracetamol and raises questions on some of the inadequately explored actions of paracetamol. <b>List of Abbreviations:</b> AM404, <i>N</i>-(4-hydroxyphenyl)-arachidonamide; CB1R, Cannabinoid receptor-1; Cmax, Maximum concentration; CNS, Central nervous system; COX, Cyclooxygenase; CSF, Cerebrospinal fluid; ED₅₀, 50% of maximal effective dose; FAAH, Fatty acid amidohydrolase; IC₅₀, 50% of the maximal inhibitor concentration; LPS, Lipopolysaccharide; NSAIDs, Non-steroidal anti-inflammatory drugs; PGE₂, Prostaglandin E₂; TRPV1, Transient receptor potential vanilloid-1.

Paracetamol: A Review of Guideline Recommendations.. 2021. https://doi.org/10.3390/jcm10153420

Musculoskeletal pain conditions are age-related, leading contributors to chronic pain and pain-related disability, which are expected to rise with the rapid global population aging. Current medical treatments provide only partial relief. Furthermore, non-steroidal anti-inflammatory drugs (NSAIDs) and opioids are effective in young and otherwise healthy individuals but are often contraindicated in elderly and frail patients. As a result of its favorable safety and tolerability record, paracetamol has long been the most common drug for treating pain. Strikingly, recent reports questioned its therapeutic value and safety. This review aims to present guideline recommendations. Paracetamol has been assessed in different conditions and demonstrated therapeutic efficacy on both acute and chronic pain. It is active as a single agent and is additive or synergistic with NSAIDs and opioids, improving their efficacy and safety. However, a lack of significant efficacy and hepatic toxicity have also been reported. Fast dissolving formulations of paracetamol provide superior and more extended pain relief that is similar to intravenous paracetamol. A dose reduction is recommended in patients with liver disease or malnourished. Genotyping may improve efficacy and safety. Within the current trend toward the minimization of opioid analgesia, it is consistently included in multimodal, non-opioid, or opioid-sparing therapies. Paracetamol is being recommended by guidelines as a first or second-line drug for acute pain and chronic pain, especially for patients with limited therapeutic options and for the elderly.

Paracetamol. https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:46195

Paracetamol is a member of the class of phenols that is 4-aminophenol in which one of the hydrogens attached to the amino group has been replaced by an acetyl group. It has a role as a ferroptosis inducer, a geroprotector, a non-steroidal anti-inflammatory drug, a non-narcotic analgesic, an antipyretic, a xenobiotic, a cyclooxygenase 2 inhibitor, a cyclooxygenase 1 inhibitor, a hepatotoxic agent, a cyclooxygenase 3 inhibitor, an environmental contaminant and a human blood serum metabolite. It is a member of acetamides and a member of phenols. It is functionally related to a 4-aminophenol.