Fosamprenavir Side Effects

Medically reviewed by Drugs.com. Last updated on Jun 16, 2024.

Applies to fosamprenavir: oral suspension, oral tablet.

Serious side effects of fosamprenavir

Along with its needed effects, fosamprenavir may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking fosamprenavir:

More common side effects

• black, tarry stools
• chills
• cough
• fever
• lower back or side pain
• painful or difficult urination
• pale skin
• skin rash
• sore throat
• ulcers, sores, or white spots in the mouth
• unusual bleeding or bruising
• unusual tiredness or weakness

Incidence not known

• blistering, peeling, loosening of the skin
• blood in the urine
• chest pain or discomfort
• diarrhea
• itching
• joint or muscle pain
• large amount of cholesterol in the blood
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
• nausea
• pain in the groin or genitals
• pain or discomfort in the arms, jaw, back, or neck
• red skin lesions, often with a purple center
• red, irritated eyes
• sharp back pain just below the ribs
• sweating
• vomiting

Other side effects of fosamprenavir

Some side effects of fosamprenavir may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common side effects

• headache
• stomach pain

Incidence not known

• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings in the mouth

For healthcare professionals

Applies to fosamprenavir: oral suspension, oral tablet.

General adverse events

Diarrhea, rash, nausea, vomiting, and headache were the most frequent moderate to severe side effects in clinical trials. Discontinuations due to side effects were 6.4% in patients using this drug compared to 5.9% in those using comparator therapies; the most common side effects leading to discontinuation of this drug (incidence up to 1%) included diarrhea, nausea, vomiting, increased AST, increased ALT, and rash.^[Ref]

Dermatologic

• Very common (10% or more): Skin rash (up to 19%)
• Common (1% to 10%): Rash/cutaneous reactions (including erythematous or maculopapular cutaneous eruptions [with or without pruritus])
• Rare (0.01% to 0.1%): Severe and/or life-threatening skin reactions (including Stevens-Johnson syndrome)
• Frequency not reported: Erythema multiforme, pruritus
• Postmarketing reports: Angioedema

Protease inhibitors:

• Frequency not reported: Lipohypertrophy^[Ref]

Skin rash (regardless of causality) was reported in about 19% of patients. Rashes were generally maculopapular and of mild or moderate intensity, some with pruritus. Rash had a median onset and duration of 11 and 13 days, respectively, and led to discontinuation of this drug in less than 1% of patients.^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (up to 13%)
• Common (1% to 10%): Nausea, vomiting, abdominal pain, increased serum lipase, loose stools, gastritis, abdominal distension, upper abdominal pain, flatulence
• Uncommon (0.1% to 1%): Gastroesophageal reflux disease
• Frequency not reported: Increased amylase
• Postmarketing reports: Oral paresthesia^[Ref]

Increased serum lipase (greater than 2 times the upper limit of normal [2 x ULN]) has been reported in up to 8% of patients.

Vomiting was reported more often in pediatric patients than adult patients.^[Ref]

Other

• Very common (10% or more): Increased fasting triglycerides (up to 11%)
• Common (1% to 10%): Fatigue
• Uncommon (0.1% to 1%): Pyrexia, increased cholesterol

Antiretroviral therapy:

• Frequency not reported: Increased weight, increased blood lipids^[Ref]

Increased fasting triglycerides (greater than 750 mg/dL) have been reported in up to 11% of patients.^[Ref]

Hepatic

• Common (1% to 10%): Elevated ALT, elevated AST
• Frequency not reported: Liver toxicity^[Ref]

Elevated ALT (greater than 5 x ULN) and AST (greater than 5 x ULN) have been reported in up to 8% and up to 6% of patients, respectively.^[Ref]

Hematologic

• Common (1% to 10%): Decreased absolute neutrophil count, neutropenia

Amprenavir:

• Frequency not reported: Acute hemolytic anemia

Protease inhibitors:

• Frequency not reported: Spontaneous bleeding in patients with hemophilia A and B^[Ref]

Decreased absolute neutrophil count (less than 750 cells/mm3) has been reported in 3% of patients.

Neutropenia was reported more often in pediatric patients than adult patients.^[Ref]

Metabolic

• Common (1% to 10%): Increased glucose, hyperlipidemia, hypertriglyceridemia
• Uncommon (0.1% to 1%): Anorexia
• Frequency not reported: Hyperglycemia, increased body fat
• Postmarketing reports: Hypercholesterolemia

Protease inhibitors:

• Frequency not reported: Hypertriglyceridemia, hypercholesterolemia, resistance to insulin
• Postmarketing reports: New onset diabetes mellitus, exacerbation of preexisting diabetes mellitus, hyperglycemia, diabetic ketoacidosis

Antiretroviral therapy:

• Frequency not reported: Increased glucose^[Ref]

Increased glucose (greater than 251 mg/dL) has been reported in 2% of patients.^[Ref]

Nervous system

• Common (1% to 10%): Headache, dizziness^[Ref]

Hypersensitivity

• Common (1% to 10%): Drug hypersensitivity^[Ref]

Cardiovascular

• Postmarketing reports: Myocardial infarction^[Ref]

Renal

• Postmarketing reports: Nephrolithiasis^[Ref]

Musculoskeletal

• Frequency not reported: Elevated creatine kinase, osteonecrosis

Protease inhibitors:

• Rare (0.01% to 0.1%): Rhabdomyolysis
• Frequency not reported: Increased creatine phosphokinase, myalgia, myositis^[Ref]

Psychiatric

• Frequency not reported: Depressive/mood disorders^[Ref]

Immunologic

• Frequency not reported: Immune reconstitution/reactivation syndrome, autoimmune disorders in the setting of immune reconstitution (e.g., Graves' disease, polymyositis, Guillain-Barre syndrome)^[Ref]

Further information

Fosamprenavir side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer