hydrocodone

Hydrocodone is an opioid analgesic used to treat moderate to severe pain and, in some formulations, to suppress coughing. It is a semi-synthetic derivative of codeine. Common forms include immediate-release tablets or capsules and combination products with acetaminophen or ibuprofen. Brand names include Vicodin, Norco, Lortab, and Vicoprofen; extended-release formulations used for chronic pain include Zohydro ER and Hysingla ER.

Mechanism and pharmacokinetics: Hydrocodone binds to mu-opioid receptors in the brain and spinal cord, altering perception of pain. Orally administered hydrocodone typically begins to take effect within 30 to 60 minutes, with immediate-release products lasting about 4 to 6 hours and extended-release products providing 12 to 24 hours of relief. Metabolism occurs in the liver, mainly via CYP3A4 and CYP2D6, and drug interactions that affect these enzymes can alter its effectiveness and risk of side effects.

Safety and regulation: Common side effects include constipation, nausea, drowsiness, dizziness, and sweating; more serious risks include respiratory depression, cognitive impairment, and the development of tolerance, dependence, and withdrawal upon discontinuation. Overdose is a medical emergency and may be treated with naloxone. In the United States, hydrocodone products are Schedule II controlled substances, with strict prescribing rules and limited or no refills. Global regulation varies by country.

History and notes: Hydrocodone has been widely used since the mid-20th century, primarily in combination with acetaminophen; concerns about abuse have led to tighter controls.