hydrocodone/acetaminophen (Vicodin, Lorcet, Hycet, Norco, Lortab Elixir, Anexsia, Vicodin ES, Vicodin HP, Xodol, Zamicet)
Classes: Analgesics, Opioid Combos
Dosing and uses of Vicodin, Lorcet (hydrocodone/acetaminophen)
Adult dosage forms and strengths
tablet: Schedule II
- 2.5mg/325mg
- 5mg/300mg, 5mg/325mg
- 7.5mg/300mg, 7.5mg/325mg
- 10mg/300mg, 10mg/325mg
oral solution/elixir: Schedule II
- (7.5mg/325mg)/15mL
- (10mg/300mg)/15mL, (10mg/325mg)/15mL
Moderate to Severe Pain
1-2 tablets (2.5-10 mg hydrocodone; 300-325 mg acetaminophen) PO q4-6hr PRn
Acetaminophen: Not to exceed 1 g/dose or 4 g/24 hr
Hydrocodone: Maximum daily dose should not exceed 60 mg/24 hr
Dosing Modifications
Hepatic impairment: Avoid chronic use or high doses of acetaminophen (ie, >4 g/day) in hepatic impairment
Pediatric dosage forms and strengths
tablet: Schedule II
- 2.5mg/325mg,
- 5mg/300mg, 5mg/325mg
- 7.5mg/300mg, 7.5mg/325mg
- 10mg/300mg, 10mg/325mg
oral solution/elixir: Schedule II
- (7.5mg/325mg)/15mL, (7.5mg/500mg)/15mL
- (10mg/300mg)/15mL, (10mg/325mg)/15mL
Moderate to Severe Pain
<2 years: Safety and efficacy not established
2-12 years: 0.135 mg/kg hydrocodone PO q4-6hr PRn
>12 years: 1-2 tablets (2.5-10 mg hydrocodone; 300-325 mg acetaminophen) PO q4-6hr PRn
Vicodin, Lorcet (hydrocodone/acetaminophen) adverse (side) effects
Frequency not defined
Biliary tract spasm
Hallucinations
Circulatory collapse
Histamine release
Physical and psychological dependence with prolonged use
Urinary tract spasm
Bradycardia
Cardiac arrest
Confusion
Decreased urination
Dizziness
Drowsiness
Dyspnea
Fatigue
Hypotension
Coma
Dysphoria
Euphoria
Lethargy
Lightheadedness
Mood changes
Stupor
Mental clouding
Nausea
Sedation
Vomiting
Weakness
Peptic ulcer
Agranulocytosis
Hemolytic anemia
Hepatic necrosis
Respiratory depression
Warnings
Black box warnings
Contains acetaminophen
Hepatotoxicity may occur with acetaminophen doses that exceed 4 g/day; take into account all acetaminophen-containing products the patient is taking, including PRN doses and OTC products
Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplantation or death
New dosage limit allows no more than 325 mg/dosage unit for prescription medications that contain acetaminophen
Healthcare professionals can direct patients to take 1 or 2 tablets, capsules, or other dosage units of a prescription product containing 325 mg of acetaminophen up to 6 times daily (12 dosage units) and still not exceed the maximum daily dose of acetaminophen (ie, 4000 mg/day)
Contraindications
Hypersensitivity
CNS depression
Severe respiratory depression
Cautions
Use caution in debilitated patients, drug abuse history, elderly patients, G6PD deficiency, head injury, hepatic dysfunction, hypothyroidism, impaired pulmonary function, increased intracranial pressure, toxic psychosis, renal dysfunction
Hydrocodone may obscure diagnosis or clinical symptoms of acute abdominal conditions
May cause CNS depression and impair ability to operate heavy machinery
Use caution in patients with cardiovascular disease, hypovolemia, or drugs that may exacerbate hypotensive effects; may cause hypotension
Acetaminophen associated with cases of acute liver failure, at times resulting in liver transplantation or death; risk increases in individuals with underlying liver disease, alcohol ingestion, and/or use of more than 1 acetaminophen-containing product (see Black box warnings)
Acetaminophen associated with rare, but serious skin reactions that can be fatal; these reactions include Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP); symptoms may include skin redness, blisters and rash
Caution and awareness are necessary regarding misuse, abuse, or diversion
Constipation may occur; take measures to prevent constipation, such as, administering stool softener and increasing fiber
Chronic alcoholics should limit acetaminophen intake to <2 g/day
Use caution in patients with adrenocortical insufficiency, including Addison's disease; long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction, infertility, mood disorders, and osteoporosis
Use caution in patients with bliary tract dysfunction, including acute pancreatitis; may cause constriction of sphincter of Oddi
Use caution in morbidly obese patients
Use hydrocodone with caution in patients with prostatic hyperplasia and/or urinary stricture
Use caution in patients with seizure disorders
Pregnancy and lactation
Pregnancy category: C
Lactation: Excreted in breast milk; breastfeeding not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Vicodin, Lorcet (hydrocodone/acetaminophen)
Mechanism of action
Acetaminophen: Acts on the hypothalamus to produce antipyresis; inhibits prostaglandin synthetase
Hydrocodone: Opioid analgesic agonist; blocks pain perception in the cerebral cortex; decreases synaptic chemical transmission throughout the CNS, which in turn inhibits pain sensation into higher centers
Metabolism
Acetaminophen: Primarily undergoes glucuronidation and sulfate conjugation; however, a small percentage is metabolized via CYP2E1 and CYP1A2 to a hepatotoxic metabolite
Hydrocodone: Metabolized in the liver to the active opioid hydromorphone via CYP2D6; also by O-demethylation, N-demethylation, and 6 ketosteroid reduction
CYP2D6 poor metabolizers may not achieve adequate analgesia
Ultrarapid metabolizers (up to 7% of whites and up to 30% of Asian and African populations) may have increased toxicity due to rapid conversion
Metabolites (acetaminophen): N-acetyl-p-benzoquinoneimine, N-acetylimidoquinone, NAPQI; further metabolized via conjugation with glutathione
Elimination
Half-life
- Hydrocodone: 3.3-4.4 hr
- Acetaminophen: 2-4 hr
Onset of action
- Hydrocodone: 10-20 min (analgesic effects)
- Acetaminophen: <1 hr (PO); 5-10 min (IV; analgesia)
Duration
- Hydrocodone: 4-8 hr
- Acetaminophen: 4-6 hr (analgesia); > 6hr (antipyretic)
Excretion
- Hydrocodone: Urine (26% of single dose)
- Acetaminophen: Urine (90-100%; principally as acetaminophen glucuronide with acetaminophen sulfate/mercaptate)