VICODIN HP
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VICODIN HP (VICODIN HP).
Hydrocodone is a mu-opioid receptor agonist that inhibits ascending pain pathways; acetaminophen inhibits cyclooxygenase and has antipyretic effects.
| Metabolism | Hydrocodone: CYP3A4 and CYP2D6; Acetaminophen: primarily glucuronidation (UGT1A1, UGT1A6, UGT1A9) and sulfation. |
| Excretion | Primarily renal: hydrocodone is eliminated as conjugated metabolites (glucuronides) ~80%; unchanged drug ~5%. Biliary/fecal: minor, <10%. |
| Half-life | Hydrocodone: 3.8-5.5 hours (mean 4.5 h). Acetaminophen: 2-3 hours. Clinical context: dosing interval every 4-6 hours for acute pain. |
| Protein binding | Hydrocodone: ~36% bound (primarily albumin). Acetaminophen: ~10-25% bound. |
| Volume of Distribution | Hydrocodone: Vd ~3-5 L/kg (extensive tissue distribution). Acetaminophen: Vd ~1 L/kg. |
| Bioavailability | Oral: hydrocodone ~60-70% (extensive first-pass metabolism); acetaminophen ~85-95%. |
| Onset of Action | Oral: 30-60 minutes for analgesia. |
| Duration of Action | Oral: 4-6 hours (analgesic effect; may be shorter with single doses, longer with repeated dosing). |
| Molecular Weight | 425.52 |
One tablet (hydrocodone bitartrate 10 mg/acetaminophen 660 mg) orally every 4-6 hours as needed for pain; maximum 6 tablets per day.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: administer every 6 hours; GFR 10-29 mL/min: administer every 8-12 hours; GFR <10 mL/min: avoid use or consider extended interval dosing. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 50% or extend interval; Child-Pugh Class C: avoid use due to risk of toxicity. |
| Pediatric use | Not approved for pediatric use; hydrocodone is contraindicated in children <6 years and not recommended in those <18 years due to risk of respiratory depression. |
| Geriatric use | Initiate at the lowest effective dose, typically one tablet every 6 hours; monitor for respiratory depression, constipation, and falls; avoid in patients with severe COPD or sleep apnea. |
| 1st trimester | Risk of neural tube defects and congenital malformations; avoid use unless clearly needed. |
| 2nd trimester | Associated with spontaneous abortion and fetal growth restriction; use only if maternal benefit outweighs fetal risk. |
| 3rd trimester | Prolonged use may cause neonatal opioid withdrawal syndrome; avoid use during labor and delivery. |
Clinical note
Comprehensive clinical and safety monograph for VICODIN HP (VICODIN HP).
| Placental transfer | Hydrocodone and acetaminophen cross the placenta. Hydrocodone is highly protein-bound, reducing fetal exposure, but transfer is significant enough to cause neonatal effects. |
| Breastfeeding | Hydrocodone and acetaminophen are excreted in breast milk. Monitor infant for drowsiness, respiratory depression, and poor feeding. Use with caution and at the lowest effective dose. |
■ FDA Black Box Warning
Risk of opioid addiction, abuse, misuse; life-threatening respiratory depression; neonatal opioid withdrawal syndrome with prolonged use during pregnancy; accidental ingestion of acetaminophen; concomitant use with benzodiazepines or other CNS depressants.
| Serious Effects |
Hypersensitivity to hydrocodone, acetaminophen, or any componentSevere respiratory depressionAcute or severe bronchial asthmaParalytic ileusConcurrent use of MAOIs or within 14 days
| Precautions | Addiction, abuse, misuse; life-threatening respiratory depression; accidental ingestion; neonatal opioid withdrawal syndrome; hepatotoxicity due to acetaminophen; interactions with CNS depressants; severe hypotension; adrenal insufficiency; and seizure risk. |
| Food/Dietary | Avoid alcohol and high-fat meals, which can increase sedation and delay absorption. Grapefruit juice may alter hydrocodone metabolism; avoid concurrent consumption. |
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| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Increased risk of oral clefts (2-3x) and neural tube defects. Second and third trimesters: Risk of miscarriage, preterm birth, intrauterine growth restriction, and neonatal opioid withdrawal syndrome (NOWS) with chronic use. Avoid in late pregnancy due to risk of respiratory depression. |
| Fetal Monitoring | Monitor maternal respiratory rate, sedation level, and bowel function. Fetal: serial ultrasound for growth restriction (if chronic use), nonstress test or biophysical profile for reduced fetal movement. Monitor for NOWS in neonates with prolonged maternal use. |
| Fertility Effects | Opioids may cause hypothalamic-pituitary-gonadal axis suppression leading to anovulation, irregular menses, and decreased fertility. Effects are dose-dependent and reversible upon discontinuation. |
| Clinical Pearls | Vicodin HP combines 10 mg hydrocodone and 300 mg acetaminophen per tablet; maximum acetaminophen dose from all sources should not exceed 4 g/day to avoid hepatotoxicity. Hydrocodone is a prodrug metabolized by CYP2D6 to hydromorphone; poor metabolizers may have reduced analgesia. Use with caution in patients with impaired respiratory function or history of substance abuse. Coadministration with CNS depressants increases sedation risk. |
| Patient Advice | Take only as prescribed; do not exceed 8 tablets per day due to acetaminophen limit. · Do not drink alcohol while taking this medication. · Avoid driving or operating machinery until you know how the drug affects you. · Do not share this medication with others; it can cause addiction and harm. · Report any signs of liver injury (yellow skin/eyes, dark urine, abdominal pain) immediately. · Store securely out of reach of children and dispose of unused tablets properly. |