Hydrocodone/paracetamol (also known as hydrocodone/acetaminophen) is the combination of the pain medications hydrocodone and paracetamol (acetaminophen). It is used to treat moderate to severe pain. It is taken by mouth. Recreational use is common in the United States.Common side effects include dizziness, sleepiness, constipation, and vomiting. Serious side effects include addiction, decreased rate of breathing, low blood pressure, serotonin syndrome, severe allergic reactions, and liver failure. Use during pregnancy may harm the baby. Use with alcohol is not recommended. Hydrocodone works by binding to the mu-opioid receptor. How paracetamol works is unclear but may involve blocking the creation of prostaglandins.Hydrocodone/paracetamol was approved for medical use in the United States in 1982. In the United States, it is a schedule II controlled substance. In 2020, it was the sixteenth most commonly prescribed medication in the United States, with more than 30 million prescriptions. It is not available in the United Kingdom, though the combination codeine/paracetamol is. It is sold under the brand names Vicodin and Norco among others. Uses
Medical
Hydrocodone/paracetamol is a fixed-dose combination consisting of the opioid hydrocodone and the non-opioid analgesic paracetamol. It is indicated for relief of moderate to severe pain of acute, chronic, or postoperative types. Hydrocodone/paracetamol comes in oral solution and tablet formulations; however strength of each component may vary. In October 2014, the Drug Enforcement Administration rescheduled hydrocodone combination drugs from schedule III to schedule II due to its risk for misuse, abuse, and diversions. Recreational
Hydrocodone diversion and recreational use has escalated in recent years due to its opioid effects.
Overdose
Hydrocodone: Respiratory depression, extreme somnolence progressing towards coma, muscle limpness, cold and clammy skin, slow heart rate, low blood pressure, abrupt loss of heart function, and death may occur.Paracetamol: Liver and kidney failure, low blood sugar coma may occur. Interactions
Hydrocodone may demonstrate an enhanced respiratory depressant effect when combined with other sedatives such as other opioids, benzodiazepines, nonbenzodiazepine sedatives, psychotropics, and anticonvulsants.Concurrent use of paracetamol with alcohol products may increase the risk of acute liver failure. Monitoring
Laboratory function tests should be used to monitor therapy in people with severe liver or renal disease. Pharmacology
Hydrocodone
Mechanism of action: Hydrocodone acts primarily as an agonist at the mu-opioid receptors, but is also a weak agonist against the delta opioid and kappa opioid receptors. Absorption/distribution: The oral formulation can be absorbed from the gastrointestinal tract and remain 20–50% bound to plasma proteins. The onset of analgesia is about 20 to 30 minutes with duration of 4 to 8 hours and t1/2 of 3 to 4 hours. Metabolism/excretion: It is metabolized to norhydrocodone by cytochrome P450 3A4 and to hydromorphone, also biologically active, by cytochrome P450 2D6. For individuals who have a defect in the gene encoding CYP2D6, the clearance of the drug will be lower and less metabolite such as hydromorphone will be formed; however, the effect on analgesia remains unknown. Paracetamol
Mechanism of action: Paracetamol acts to inhibit COX enzyme, which is responsible for prostaglandin synthesis. Prostaglandins increase the perception of pain. Inhibition of prostaglandin production helps to alleviate pain.