Medically reviewed by Drugs.com. Last updated on Jun 11, 2020.
(fos KAR net)
- Phosphonoformic Acid
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, Intravenous [preservative free]:
Foscavir: 24 mg/mL (250 mL)
Brand Names: U.S.
- Antiviral Agent
Pyrophosphate analogue which acts as a noncompetitive inhibitor of many viral RNA and DNA polymerases as well as HIV reverse transcriptase. Similar to ganciclovir, foscarnet is a virostatic agent. Foscarnet does not require activation by thymidine kinase.
Vd: ~0.5 L/kg; up to 28% of cumulative IV dose may be deposited in bone
Biotransformation does not occur
Urine (≤28% as unchanged drug)
Elimination: ~3 to 4 hours; terminal: ~88 hours (due to bone deposition)
Protein binding: 14% to 17%
Special Populations: Renal Function Impairment
CrCl of 50 to 80 mL/minute has a clearance of about 1.33 mL/minute/kg and a plasma half-life of about 3.35 hours. CrCl of 25 to 49 mL/minute has a clearance of about 0.46 mL/minute/kg and a plasma half-life of about 13 hours. CrCl of 10 to 24 mL/minute has a clearance of 0.43 mL/minute/kg and plasma half-life about 25.3 hours.
Use: Labeled Indications
Cytomegalovirus treatment, ophthalmic disease (retinitis): Treatment of cytomegalovirus (CMV) retinitis in persons with AIDS
Herpes simplex virus: Treatment of acyclovir-resistant mucocutaneous herpes simplex virus (HSV) infection in immunocompromised persons (eg, with advanced AIDS)
Off Label Uses
Cytomegalovirus prevention, allogeneic hematopoietic cell transplant recipients
Data from one randomized, open-label trial in patients with cancer who underwent allogeneic hematopoietic cell transplant (HCT) demonstrated similar efficacy between foscarnet and ganciclovir with up to 4 weeks of preemptive treatment of cytomegalovirus (CMV) infection and supports the use of foscarnet in this setting. Foscarnet was also found to be associated with a lower incidence of severe neutropenia and discontinuation due to hematologic toxicity (ie, neutropenia or thrombocytopenia) [Reusser 2002].
Based on collaborative guidelines for preventing infectious complications in HCT recipients, foscarnet is recommended as an alternative agent for preemptive and prophylactic therapy after transplantation [ASBMT [Tomblyn 2009]].
Cytomegalovirus treatment, gastrointestinal disease (esophagitis or colitis)
Based on the US Department of Health and Human Services (HHS) Guidelines for Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV, foscarnet is an effective and recommended alternative agent for the treatment of esophagitis or colitis due to CMV disease in patients with HIV.
Cytomegalovirus treatment, neurological disease
Based on the US Department of HHS Guidelines for Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV, foscarnet is an effective and recommended agent to be used in combination with ganciclovir for the treatment of neurological disease due to CMV in patients with HIV.
Varicella zoster virus, progressive outer retinal necrosis
Based on the US Department of HHS Guidelines for Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV, foscarnet is a recommended intravitreal agent to be used in combination with systemic antiviral therapy for the treatment of progressive outer retinal necrosis due to varicella zoster virus in patients with HIV.
Clinically significant hypersensitivity to foscarnet or any component of the formulation.
Gastrointestinal disease (esophagitis, colitis) (alternative agent) (off-label use): IV: 60 mg/kg/dose every 8 hours or 90 mg/kg/dose every 12 hours for 21 to 42 days or until symptom resolution (HHS [OI adult 2020]).
Neurological disease (off-label use): IV: 60 mg/kg/dose every 8 hours or 90 mg/kg/dose every 12 hours in combination with ganciclovir; optimal duration not established (HHS [OI adult 2020]).
Ophthalmic disease (retinitis):
IV (alternative agent):
Induction treatment: 60 mg/kg/dose every 8 hours or 90 mg/kg/dose every 12 hours for 14 to 21 days; for immediate sight-threatening lesions, administer in combination with intravitreal therapy (HHS [OI adult 2020]).
Maintenance therapy: 90 to 120 mg/kg/dose once daily; due to lower toxicity, begin with 90 mg/kg/dose once daily, may escalate to 120 mg/kg/dose once daily if lower dose tolerated or for retinitis progression (manufacturer’s labeling). Duration of maintenance therapy is ≥3 to 6 months and until lesions are inactive and until CD4 count is >100 cells/mm3 for 3 to 6 months in response to antiretroviral therapy in patients with HIV (HHS [OI adult 2020]).
Intravitreal (off label):
Induction treatment: 2.4 mg per 0.1 mL injected into vitreum (Diaz-Llopis 1994; HHS [OI adult 2020]) for 1 to 4 doses administered over 7 to 10 days for immediate sight-threatening lesions; must be used in combination with systemic antiviral therapy (HHS [OI adult 2020]).
Cytomegalovirus prevention, allogeneic hematopoietic cell transplant recipients (off-label use; alternative agent):
Preemptive therapy: IV:
<100 days post-transplant: Induction: 60 mg/kg/dose every 12 hours for 7 to 14 days, followed by maintenance therapy: 90 mg/kg/dose once daily if CMV is still detectable and declining, continue until indicator test is negative. Minimum total duration (induction and maintenance) is 2 weeks (ASBMT/IDSA [Tomblyn 2009]).
>100 days post-transplant: 60 mg/kg/dose every 12 hours for 14 days, continue treatment with 90 mg/kg/dose once daily for 7 to 14 days or until indicator test is negative (ASBMT/IDSA [Tomblyn 2009]).
Prophylactic therapy: IV: 60 mg/kg/dose every 12 hours for 7 days, followed by 90 to 120 mg/kg/dose once daily until day 100 after HCT (ASBMT/IDSA [Tomblyn 2009]).
Herpes simplex infection, mucocutaneous (acyclovir-resistant):
IV: 40 mg/kg/dose every 8 to 12 hours for 14 to 21 days or until healed.
Topical (off label): Patients with HIV: Apply foscarnet 1% (extemporaneously prepared) 5 times daily for ≥21 to 28 days, based on clinical response (HHS [OI adult 2020]).
Varicella zoster virus, progressive outer retinal necrosis (off-label use):
Intravitreal (off-label): 1.2 mg per 0.05 mL injected in the vitreum twice weekly; must be used in combination with systemic antiviral therapy (HHS [OI adult 2020]).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Refer to adult dosing.
Cytomegalovirus (CMV) infection (HIV-exposed/-positive): Limited data available (HHS [OI adult 2018]; HHS [OI pediatric 2016]):
Treatment; induction: In addition to antiviral therapy, antiretroviral therapy (ART) should be optimized.
CNS, neurological disease: Infants, Children, and Adolescents: IV: 180 mg/kg/day in divided doses every 8 or 12 hours; use in combination with ganciclovir; begin treatment promptly and continue until symptom improvement; follow with chronic suppression
GI disease (esophagitis or colitis); ganciclovir-intolerant or -resistant: Adolescents: IV: 180 mg/kg/day in divided doses every 8 or 12 hours for 21 to 42 days or until resolution of symptoms
Retinitis: Use as a component of initial therapy if immediate, sight-threatening lesions are present.
Infants and Children: IV: 180 mg/kg/day in divided doses every 8 or 12 hours; continue for 14 to 21 days. Use in combination with ganciclovir if monotherapy fails or in sight-threatening illnesses. Follow treatment with chronic suppression (HHS [OI pediatric 2016]).
Adolescents: Combination therapy with intravitreal and intravenous antiviral therapy recommended; follow treatment/induction with chronic suppression (HHS [OI adult 2018])
IV: 180 mg/kg/day in divided doses every 8 or 12 hours for 14 to 21 days
Intravitreal: 2.4 mg/dose for 1 to 4 doses administered over 7 to 10 days in combination with valganciclovir (oral), ganciclovir (IV), foscarnet (IV), or cidofovir (IV)
Chronic suppressive (maintenance) therapy:
Secondary prophylaxis (following treatment for prior disseminated disease, retinitis, or neurologic disease or GI disease with relapse): Infants, Children, and Adolescents: IV: 90 to 120 mg/kg/dose once daily; duration of therapy dependent on multiple factors (eg, infection, age, CD4 cell count, response) and is typically several months (HHS [OI adult 2018]; HHS [OI pediatric 2016])
Cytomegalovirus (CMV) infection after stem cell transplantation (HSCT); alternate agent: Limited data available (IDSA [Tomblyn 2009]): Infants, Children, and Adolescents: IV:
<100 days post-transplant: Induction: 60 mg/kg/dose every 12 hours for 7 to 14 days; follow with maintenance therapy if CMV is still detectable and declining
>100 days post-transplant: 60 mg/kg/dose every 12 hours for 14 days; follow with maintenance therapy
Maintenance: 90 mg/kg/dose once daily; duration dependent on post-transplant days:
<100 days post-transplant: Minimum duration is at least 7 days and continue daily until CMV indicator test is negative
>100 days post-transplant: Continue for 7 to 14 days or until CMV indicator test is negative
Prophylactic therapy: Engraftment to <100 days post-transplant: 60 mg/kg/dose every 12 hours for 7 days, followed by 90 to 120 mg/kg/dose once daily until day 100 after HSCT
Herpes simplex virus (HSV) infection acyclovir-resistant; treatment (HIV-exposed/-positive): Limited data available:
Infants and Children: IV: 120 mg/kg/day in divided doses every 8 or 12 hours; duration depends on infection site (HHS [OI pediatric 2016])
Adolescents: IV: 80 to 120 mg/kg/day in divided doses every 8 or 12 hours; continue until clinical response (HHS [OI adult 2018])
Varicella zoster virus (VZ) infection (HIV-exposed/-positive): Limited data available:
Chickenpox not responding to acyclovir; treatment: Infants and Children: IV: 120 to 180 mg/kg/day in divided doses every 8 hours for 7 to 10 days or until no new lesions have appeared for 48 hours (HHS [OI pediatric 2016])
Zoster: Progressive outer retinal necrosis; treatment (HHS [OI adult 2018]; HHS [OI pediatric 2016]): Infants, Children, and Adolescents: Note: In addition to antiviral therapy, optimize ART.
IV: 90 mg/kg/dose every 12 hours in combination with ganciclovir (systemic, IV) and intravitreal foscarnet and/or ganciclovir
Intravitreal: 1.2 mg/0.05 mL per dose twice weekly in combination with systemic foscarnet and ganciclovir and/or intravitreal ganciclovir
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Foscarnet should be diluted in D5W or NS. For peripheral line administration, foscarnet must be diluted to 12 mg/mL with D5W or NS. For central line administration, foscarnet may be administered undiluted.
IV: Foscarnet is administered by intravenous infusion, using an infusion pump, at a rate not exceeding 1 mg/kg/minute. Adult induction doses of 60 mg/kg are administered over 1 hour. Adult maintenance doses of 90 to 120 mg/kg are infused over 2 hours. Undiluted (24 mg/mL) solution can be administered without further dilution when using a central venous catheter for infusion. For peripheral vein administration, the solution must be diluted to a final concentration of 12 mg/mL. The manufacturer recommends 750 to 1,000 mL of NS or D5W be administered prior to first infusion to establish diuresis. With subsequent infusions of 90 to 120 mg/kg, this volume would be repeated. If the dose were 40 to 60 mg/kg, then the volume could be reduced to 500 mL. After the first dose, the hydration fluid should be administered concurrently with foscarnet.
Intravitreal: Off-label route: Withdraw solution directly from infusion bottle as it is already diluted to appropriate concentration for intravitreal administration. Pass through 0.22 micron filter prior to injection (Diaz-Llopis 1994; Martinez-Castillo 2012).
Some products may contain sodium.
Store intact bottles at room temperature of 20°C to 25°C (68°F to 77°F) and protect from temperatures >40°C (>104°F) and from freezing. Following dilution in D5W or NS, solutions are stable for 24 hours at room temperature or under refrigeration.
Acyclovir-Valacyclovir: Foscarnet may enhance the nephrotoxic effect of Acyclovir-Valacyclovir. Avoid combination
Aminoglycosides: Foscarnet may enhance the nephrotoxic effect of Aminoglycosides. Avoid combination
Amphotericin B: Foscarnet may enhance the nephrotoxic effect of Amphotericin B. Avoid combination
CycloSPORINE (Systemic): Foscarnet may enhance the nephrotoxic effect of CycloSPORINE (Systemic). Avoid combination
Haloperidol: QT-prolonging Agents (Indeterminate Risk - Caution) may enhance the QTc-prolonging effect of Haloperidol. Monitor therapy
Loop Diuretics: May increase the serum concentration of Foscarnet. Management: When diuretics are indicated during foscarnet treatment, thiazides are recommended over loop diuretics. If patients receive loop diuretics during foscarnet treatment, monitor closely for evidence of foscarnet toxicity. Consider therapy modification
Methotrexate: Foscarnet may enhance the nephrotoxic effect of Methotrexate. Avoid combination
Pentamidine (Systemic): May enhance the adverse/toxic effect of Foscarnet. The specific toxicities may include hypocalcemia, renal failure, and QT-prolongation. Management: Consider alternatives to this combination when possible. If this combination must be used, monitor patients more closely for hypocalcemia, renal dysfunction, and QT interval prolongation. Consider therapy modification
QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Caution) may enhance the QTc-prolonging effect of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy
Tacrolimus (Systemic): Foscarnet may enhance the nephrotoxic effect of Tacrolimus (Systemic). Avoid combination
Talimogene Laherparepvec: Antiherpetic Antivirals may diminish the therapeutic effect of Talimogene Laherparepvec. Monitor therapy
Central nervous system: Headache (26%)
Endocrine & metabolic: Hypokalemia (16% to 48%), hypocalcemia (15% to 30%), hypomagnesemia (15% to 30%), hypophosphatemia (8% to 26%)
Gastrointestinal: Nausea (47%), diarrhea (30%), vomiting (26%)
Hematologic & oncologic: Anemia (33%), granulocytopenia (17%)
Renal: Renal insufficiency (27%)
Miscellaneous: Fever (65%)
1% to 10%:
Cardiovascular: Chest pain (1% to 5%; including transient chest pain as part of infusion reactions), edema (1% to 5%), facial edema (1% to 5%), first degree atrioventricular block (1% to 5%), flushing (1% to 5%), hypertension (1% to 5%), hypotension (1% to 5%), palpitations (1% to 5%), sinus tachycardia (1% to 5%), ST segment changes on ECG (1% to 5%), thrombosis (1% to 5%)
Central nervous system: Seizure (10%), anxiety (≥5%), confusion (≥5%), depression (≥5%), dizziness (≥5%), fatigue (≥5%), hypoesthesia (≥5%), malaise (≥5%), neuropathy (≥5%), pain (≥5%), paresthesia (≥5%), rigors (≥5%), abnormal electroencephalogram (1% to 5%), aggressive behavior (1% to 5%), agitation (1% to 5%), amnesia (1% to 5%), aphasia (1% to 5%), ataxia (1% to 5%), cerebrovascular disease (1% to 5%), dementia (1% to 5%), hallucination (1% to 5%), insomnia (1% to 5%), meningitis (1% to 5%), nervousness (1% to 5%), sensory disturbance (1% to 5%), somnolence (1% to 5%), stupor (1% to 5%)
Dermatologic: Diaphoresis (≥5%), skin rash (≥5%), dermal ulcer (1% to 5%), erythematous rash (1% to 5%), maculopapular rash (1% to 5%), pruritus (1% to 5%), seborrhea (1% to 5%), skin discoloration (1% to 5%)
Endocrine & metabolic: Hyperphosphatemia (6%), electrolyte disturbance (≥5%), abnormal albumin-Globulin ratio (1% to 5%), acidosis (1% to 5%), albuminuria (1% to 5%), cachexia (1% to 5%), hyponatremia (1% to 5%), increased lactate dehydrogenase (1% to 5%), increased thirst (1% to 5%), weight loss (1% to 5%)
Gastrointestinal: Abdominal pain (≥5%), anorexia (≥5%), aphthous stomatitis (1% to 5%), cachexia (1% to 5%), constipation (1% to 5%), dysgeusia (1% to 5%), dyspepsia (1% to 5%), dysphagia (1% to 5%), flatulence (1% to 5%), melena (1% to 5%), pancreatitis (1% to 5%), xerostomia (1% to 5%)
Genitourinary: Nephrotoxicity (8%), dysuria (1% to 5%), nocturia (1% to 5%), urinary retention (1% to 5%), urinary tract infection (1% to 5%)
Hematologic & oncologic: Bone marrow suppression (10%), leukopenia (≥5%), mineral abnormalities (≥5%), neutropenia (≥5%), abnormal white cell differential (1% to 5%), altered platelet function (1% to 5%), lymphadenopathy (1% to 5%), pseudolymphoma (1% to 5%), rectal hemorrhage (1% to 5%), sarcoma (1% to 5%), thrombocytopenia (1% to 5%)
Hepatic: Abnormal hepatic function tests (1% to 5%), increased lactate dehydrogenase (1% to 5%), increased serum alkaline phosphatase (1% to 5%), increased serum ALT (1% to 5%), increased serum AST (1% to 5%)
Infection: Infection (≥5%), sepsis (≥5%), abscess, bacterial infection (1% to 5%), fungal infection (1% to 5%)
Local: Inflammation at injection site (1% to 5%), pain at injection site (1% to 5%)
Neuromuscular & skeletal: Muscle spasm (≥5%), neuropathy (peripheral; ≥5%), weakness (≥5%), arthralgia (1% to 5%), back pain (1% to 5%), leg cramps (1% to 5%), myalgia (1% to 5%), tremor (1% to 5%)
Ophthalmic: Visual disturbance (≥5%), conjunctivitis (1% to 5%), eye pain (1% to 5%)
Renal: Decreased creatinine clearance (≥5%), increased serum creatinine (≥5%), acute renal failure (1% to 5%), increased blood urea nitrogen (1% to 5%), polyuria (1% to 5%)
Respiratory: Cough (≥5%), dyspnea (≥5%), bronchospasm (1% to 5%), flu-like symptoms (1% to 5%), hemoptysis (1% to 5%), pharyngitis (1% to 5%), pneumonia (1% to 5%), pneumothorax (1% to 5%), pulmonary infiltrates (1% to 5%), respiratory failure (1% to 5%), respiratory insufficiency (1% to 5%), rhinitis (1% to 5%), sinusitis (1% to 5%), stridor (1% to 5%)
<1%, postmarketing, and/or case reports: Coma, dehydration, diabetes insipidus (usually nephrogenic), erythema multiforme, esophageal ulcer, extravasation, Fanconi syndrome, gastrointestinal hemorrhage, glomerulonephritis, hematuria, hypercalcemia, hypersensitivity reaction (including anaphylactic shock, angioedema, urticaria), hypoproteinemia, increased amylase, increased creatine phosphokinase, increased gamma-glutamyl transferase, increased serum lipase, local irritation (genitals), localized edema, myasthenia, myopathy, myositis, nephrolithiasis, nephrotic syndrome, pancytopenia, penile ulceration, prolonged QT interval on ECG, proteinuria, renal disease (crystal-induced), renal tubular acidosis, renal tubular necrosis, rhabdomyolysis, SIADH, status epilepticus, Stevens-Johnson syndrome, torsades de pointes, toxic epidermal necrolysis, vaginal ulcer, ventricular arrhythmia
ALERT: U.S. Boxed WarningRenal impairment:
Renal impairment is the major toxicity of foscarnet. Frequent monitoring of serum creatinine, with dose adjustment for changes in renal function, and adequate hydration with administration of foscarnet is imperative.Seizures:
Seizures, related to alterations in plasma minerals and electrolytes, have been associated with foscarnet treatment. Therefore, patients must be carefully monitored for such changes and their potential sequelae. Mineral and electrolyte supplementation may be required.Appropriate use:
Foscarnet is indicated for use only in immunocompromised patients with cytomegalovirus (CMV) retinitis and mucocutaneous acyclovir-resistant herpes simplex virus (HSV) infections.
Concerns related to adverse effects:
• Dental effects: Foscarnet is deposited in teeth and bone of young, growing animals; it has adversely affected tooth enamel development in rats.
• Electrolyte imbalance: Imbalance of serum electrolytes or minerals occurs in at least 15% of patients (hypocalcemia, low ionized calcium, hyper/hypophosphatemia, hypomagnesemia, or hypokalemia); reducing infusion rate may decrease/prevent symptoms. Patients with low ionized calcium may experience perioral tingling, numbness, paresthesias, tetany, and seizures. Correct electrolytes before initiating therapy; use caution in patients who have any underlying electrolyte imbalances, those with neurologic or cardiac abnormalities, and those receiving medications that are influenced by calcium levels. Use caution when administering other medications that cause electrolyte imbalances. Patients who experience signs or symptoms of an electrolyte imbalance should be assessed immediately.
• Hematologic effects: May cause anemia and granulocytopenia.
• Hypersensitivity: Serious hypersensitivity reactions, including anaphylactic shock and angioedema, have been reported. Discontinue immediately and institute appropriate medical therapy if an acute reaction occurs.
• Renal impairment: [US Boxed Warning]: Renal impairment occurs to some degree in the majority of patients treated with foscarnet; renal impairment may occur at any time (though typically during second week of induction therapy) and is usually reversible within 1 week following dose adjustment or discontinuation of therapy, however, several patients have died with renal failure within 4 weeks of stopping foscarnet; therefore, renal function should be closely monitored during both induction and maintenance therapy. To reduce the risk of nephrotoxicity and the potential to administer a relative overdose, always calculate the CrCl even if serum creatinine is within the normal range. Dosage adjustments are recommended for renal dysfunction; safety and efficacy in patients with a baseline Scr >2.8 mg/dL or CrCl <50 mL/minute are limited. Use in patients with CrCl <0.4 mL/kg/minute is not recommended. Adequate hydration may reduce the risk of nephrotoxicity; the manufacturer makes specific recommendations regarding this (see Administration).
• QT prolongation: QT prolongation, including torsades de pointes, has been reported; some reports occurred in patients with confounding risk factors (eg, underlying cardiac disease, electrolyte abnormalities, concomitant medications). Use with caution in patients with a history of QT prolongation or those at increased risk for QT prolongation.
• Seizures: [US Boxed Warning]: Seizures related to plasma electrolyte/mineral imbalance may occur; incidence has been reported in up to 10% of HIV patients. Risk factors for seizures include impaired baseline renal function, low total serum calcium, and underlying CNS condition. Some patients who have experienced seizures have been able to continue or resume foscarnet treatment after their mineral or electrolyte abnormality has been corrected, their underlying disease state treated, or their dose decreased.
• Vascular irritant: Administer only into vein with adequate blood flow to prevent tissue irritation/ulceration. Genital vascular tissue damage has been reported; adequate hydration recommended.
Disease related concerns:
• Heart failure: Due to sodium content, use with caution in patients with heart failure.
• Appropriate use: [US Boxed Warning]: Indicated only for immunocompromised patients with CMV retinitis and mucocutaneous acyclovir-resistant HSV infection.
24-hour creatinine clearance, ECG, and electrolytes at baseline and periodically thereafter (when clinically appropriate). During induction therapy: Obtain complete blood counts, and electrolytes (including serum creatinine, calcium, magnesium, potassium, and phosphorus) twice weekly and then one weekly during maintenance therapy. More frequent monitoring may be required in some patients. Check hydration status before and after infusion.
Information related to use of foscarnet in pregnancy is limited (Alvarez-McLeod 1999).
Foscarnet is not the preferred treatment of cytomegalovirus infection in pregnant women. Monitoring of amniotic fluid volumes by ultrasound is recommended weekly after 20 weeks of gestation to detect oligohydramnios if foscarnet is used. In general, intravitreous injections for local therapy are preferred for retinal disease to limit systemic exposure (HHS [OI adult 2019]).
What is this drug used for?
• It is used to treat a type of herpes infection that cannot be treated by another drug.
• It is used to treat a viral infection of the eyes in people who have AIDS.
• It may be given to you for other reasons. Talk with the doctor.
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
• Upset stomach
• Throwing up
• Feeling dizzy, tired, or weak
• Not hungry
• Sweating a lot
• Stomach pain
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
• Fluid and electrolyte problems like mood changes, confusion, muscle pain or weakness, abnormal heartbeat, severe dizziness, passing out, fast heartbeat, increased thirst, seizures, loss of strength and energy, not hungry, unable to pass urine or change in amount of urine passed, dry mouth, dry eyes, upset stomach, or throwing up
• Kidney problems like unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain
• Abnormal heartbeat
• Passing out
• Fast heartbeat
• Burning or numbness feeling
• Trouble controlling body movements
• Shortness of breath
• Stiff muscles
• Vision changes
• Genital irritation
• Severe injection site redness, burning, pain, swelling, or leaking of fluid
• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
More about foscarnet
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- En Español
- Drug class: miscellaneous antivirals
Other brands: Foscavir