Drug information of Amprenavir

Amprenavir

فارسی

Amprenavir inhibits HIV-1 protease by binding to the enzyme's active site. This prevents the processing of viral gag and gag-pol polyprotein precursors and results in the formation of immature noninfectious viral particles.

Mechanism of effect

Amprenavir is a protease inhibitor with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1.

 Amprenavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs.

Pharmacodynamic

Absorption:

Rapidly absorbed after oral administration in HIV-1-infected patients.

time to peak concentration (Tmax): 1-2 hours after a single oral dose.

Distribution:

Not Available
Metabolism:

Not Available

Elimination:
Half-life: 7.1-10.6 hours

Dosage

Agenerase: Capsule 50mg

Agenerase: Capsule 150mg

Agenerase: Suspension 15mg 

Adults:

  • HIV infection: 1200 mg ORALLY twice a day
  • HIV infection: When used with ritonavir 200 mg once daily, amprenavir 1200 mg ORALLY once daily
  • HIV infection: When used with ritonavir 100 mg twice daily, amprenavir 600 mg ORALLY twice daily 

Dose Adjustment:

  • renal impairment: oral solution CONTRAINDICATED in patients with renal failure due to propylene glycol content; use with caution in patients with renal impairment
  • hepatic failure: oral solution CONTRAINDICATED in patients with hepatic failure
  • hepatic impairment: Child-Pugh score 5-8; 450 mg twice daily (capsules), 513 mg twice daily (solution); Child-Pugh score 9-12; 300 mg twice daily (capsules), 342 mg twice daily (solution) 

Pediatrics:

  • HIV infection: capsules; 13 to 16 years, 1200 mg ORALLY twice daily
  • HIV infection: capsules; 4 to 16 years and less than 50 kg, 20 mg/kg ORALLY twice daily or 15 mg/kg 3 times a day; maximum 2400 mg/day
  • HIV infection: solution; 4 to 16 years and less than 50 kg, 22.5 mg/kg ORALLY twice daily or 17 mg/kg 3 times a day; maximum 2800 mg/day)
  • HIV infection: solution; 13 years and older and 50 kg or more, 1400 mg ORALLY twice daily

FDA-Labeled:

  • HIV infection: Adult: yes
  • HIV infection: Pediatric: yes (4 years and older)

Alerts

  • alcohol use; may compete for the same metabolic pathway of elimination as the excipient, propylene glycol (solution only)
  • amprenavir solution should only be used when the capsules or other protease inhibitor formulations are not therapeutic options
  • anticoagulant therapy; amprenavir provides high daily doses of vitamin E that may exacerbate blood coagulation defect of vitamin K deficiency caused by anticoagulant therapy
  • Diabetes mellitus; potential for exacerbation, new onset, or hyperglycemia may occur
  • Ethnic populations (Asians, Eskimos, Native Americans); may be at increased risk for propylene glycol toxicity (solution only)
  • Hemolytic anemia, acute has been reported
  • Hepatic impairment ; amprenavir is principally metabolized in the liver
  • Hypertriglyceridemia may occur
  • Malabsorption; amprenavir provides high daily doses of vitamin E that may exacerbate blood coagulation defect of vitamin K deficiency caused by malabsorption
  • Opportunistic infections, indolent or residual; inflammatory response (immune reconstitution syndrome) may occur
  • Sulfonamide allergy; amprenavir is a sulfonamide
  • Stevens-Johnson syndrome and other severe and life-threatening skin reactions have occurred
  • Women; may be at increased risk for propylene glycol toxicity (solution only)

Points of recommendation

  • Advise patient to practice safe sex. Drug does not prevent HIV transmission.
  • Instruct patient to report signs/symptoms of increased bleeding, anemia, hepatotoxicity, or nephrotoxicity.
  • Patient may take with or without food, but should avoid high-fat meals.
  • Patient should take 1 h before or after antacids or buffered didanosine.
  • Instruct patient to avoid alcohol, supplemental vitamin E, and St. John's Wort.
  • Advise patient there are multiple significant drug-drug interactions for this drug. Consult healthcare professional prior to new drug use (including over-the-counter and herbal drugs).
If a patient misses a dose and it has been longer than 4 h late, skip missed dose and take at the next regularly scheduled time..

Pregnancy level

D

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