Foscavir Side Effects

Generic name: foscarnet

Note: This document contains side effect information about foscarnet. Some of the dosage forms listed on this page may not apply to the brand name Foscavir.

Some side effects of Foscavir may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

For the Consumer

Applies to foscarnet: intravenous solution

Get emergency medical help if you have any of these signs of an allergic reaction while taking foscarnet (the active ingredient contained in Foscavir) hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using foscarnet and call your doctor at once if you have any of these serious side effects:

• urinating less than usual or not at all;

• drowsiness, confusion, mood changes, increased thirst, loss of appetite, nausea and vomiting;

• swelling, weight gain, feeling short of breath;

• numbness or tingling around your mouth or in your hands or feet;

• dry mouth, increased thirst, restless feeling, increased urination, muscle pain or weakness, fainting, or seizure (convulsions);

• fever, chills, body aches, flu symptoms;

• pale skin, feeling light-headed, rapid heart rate, trouble concentrating; or

• restless muscle movements in your eyes, tongue, jaw, or neck;

• trouble breathing; or

• pain or burning when you urinate.

Less serious side effects of foscarnet may include:

• anxiety, depressed mood;

• stomach pain;

• headache, dizziness;

• cough;

• increased sweating;

• skin rash;

• problems with vision;

• tired feeling;

• joint or muscle pain; or

• pain or swelling where the injection was given.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to foscarnet: intravenous solution

General

Renal impairment is the major toxicity of foscarnet (the active ingredient contained in Foscavir) The most frequent adverse events reported during clinical trials included fever (65%), nausea (47%), anemia (33%), diarrhea (30%), abnormal renal function (27%), vomiting (26%), headache (26%), and seizures (10%). Adverse events classified as severe included death (14%), abnormal renal function (14%), bone marrow suppression (10%), anemia (9%), and seizures (7%).

Renal

Renal side effects have included dose-related renal impairment, which is the major toxicity of foscarnet (the active ingredient contained in Foscavir) and has occurred in up to 33% of patients. Acute renal failure, serum creatinine elevations greater than or equal to 2.9 mg/dL, renal tubular acidosis, and renal calculi have also been reported.

Renal adverse effects are due to acute tubular necrosis, possibly from deposition of foscarnet crystals in the renal tubules and capillaries. Renal failure as well as tubular dysfunction such as nephrogenic diabetes insipidus may result. The development of nephrotoxicity was most common during the third week of therapy in one study.

Nephrotoxicity is reversible in patients with previously adequate renal function. Hydration with 2.5 liters of normal saline per day beginning the day before foscarnet therapy has been shown to decrease the incidence of nephrotoxicity.

Gastrointestinal

Gastrointestinal side effects have included nausea (47%), vomiting (26%), diarrhea (30%), anorexia (5% or more), and abdominal pain (5% or more). Constipation, dysphagia, dyspepsia, rectal hemorrhage, dry mouth, melena, flatulence, ulcerative stomatitis, and pancreatitis have been reported in 1% to 5% of patients. An isolated case of uvula and esophageal ulceration has been reported.

Hematologic

Hematologic side effects have included anemia (33%), neutropenia (17%), granulocytopenia (5% or more), and leukopenia (5% or more). Thrombocytopenia, platelet abnormalities, thrombosis, blood cell abnormalities, and lymphadenopathy have been reported in 1% to 5% of patients.

Nervous system

Nervous system side effects have included headache (26%) and seizures (10%). Paresthesia, dizziness, involuntary muscle contractions, hypoesthesia, neuropathy, and grand mal seizures have been reported in greater than or equal to 5% of patients. Tremor, ataxia, dementia, stupor, generalized spasms, sensory disturbances, meningitis, aphasia, abnormal coordination, leg cramps, and EEG abnormalities have been reported in 1% to 5% of patients. Risk factors for foscarnet-related seizures include low neutrophil count, central nervous system disease, impaired renal function, and electrolyte and metabolic abnormalities.

Metabolic

Metabolic disturbances have occurred in 15% to 40% of patients treated with foscarnet (the active ingredient contained in Foscavir) and include hypocalcemia, hypomagnesemia, hypokalemia, hyponatremia secondary to nephrogenic diabetes insipidus, and hypo- and hyperphosphatemia. More severe metabolic abnormalities have resulted in tremors, twitches, arrhythmias, parenthesis, and seizures. Dehydration, hypoproteinemia, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and increased amylase and creatinine phosphokinase have been reported in less than 1% of patients. Hypercalcemia has also been reported.

Serum ionized calcium concentrations have been shown to decrease acutely in a dose-dependent manner following an infusion of foscarnet. Total calcium and phosphate levels were not significantly affected. Foscarnet is believed to complex with ionized calcium.

Other

Other side effects have included fever (65%), and fatigue, rigors, asthenia, malaise, pain, infection, and sepsis in greater than or equal to 5% of patients.

Local

Local side effects have included injection site pain and inflammation.

Dermatologic

Dermatologic side effects have included rash and increased sweating in greater than or equal to 5% of patients. Pruritus, skin ulceration, seborrhea, erythematous rash, maculopapular rash, and skin discoloration have been reported in 1% to 5% of patients. Erythema multiforme, toxic epidermal necrolysis, eosinophilic folliculitis, and Stevens-Johnson syndrome have been reported during postmarketing experience.

Cardiovascular

Cardiovascular side effects have included hypertension, palpitations, ECG abnormalities, sinus tachycardia, first degree AV block, nonspecific ST-T segment changes, hypotension, flushing, cerebrovascular disorder in 1% to 5% of patients. Cardiac arrest, coma, and other cardiovascular complications have been reported in less than 1% of patients.

Reversible cardiac dysfunction has been reported in one patient receiving foscarnet, who experienced shortness of breath, increased heart rate, and pulmonary edema, which reoccurred upon rechallenge. Serum electrolytes were within normal limits. Ventricular arrhythmia and QT interval prolongation have been reported during postmarketing experience.

Hepatic

Hepatic side effects have included abnormal hepatic function, abnormal A-G ratio, increased SGPT, and increased SGOT in 1% to 5% of patients. Increased gamma glutamyl transpeptidase has been reported during postmarketing experience.

Musculoskeletal

Musculoskeletal side effects have included arthralgia and myalgia in 1% to 5% of patients. Myopathy, myositis, muscle weakness, and rhabdomyolysis have been reported during postmarketing experience.

Oncologic

Oncologic side effects have included lymphoma-like disorder and sarcoma in 1% to 5% of patients.

Respiratory

Respiratory side effects have included coughing and dyspnea in greater than or equal to 5% of patients. Pneumonia, sinusitis, pharyngitis, rhinitis, respiratory disorders, respiratory insufficiency, pulmonary infiltration, stridor, pneumothorax, hemoptysis, and bronchospasm have been reported in 1% to 5% of patients.

Psychiatric

Psychiatric side effects have included confusion and anxiety in greater than or equal to 5% of patients. Insomnia, somnolence, nervousness, amnesia, agitation, aggressive reaction, and hallucination have been reported in 1% to 5% of patients.

Ocular

Ocular side effects have included eye abnormalities, eye pain, and conjunctivitis in 1% to 5% of patients.

Genitourinary

Penile ulcerations have been reported to occur after a median of 11 days of induction therapy and 30 days of maintenance therapy, and heal within six days of drug discontinuation. Ulceration has been reported more often in uncircumcised patients. Vulvar erosion may also occur but is less common. Penile ulceration is thought to result from local irritation by high concentrations of foscarnet (the active ingredient contained in Foscavir) in the urine. Good hygiene may help reduce irritation.

Genitourinary side effects have included albuminuria, dysuria, polyuria, urethral disorder, urinary retention, urinary tract infections, and nocturia in 1% to 5% of patients, and hematuria in less than 1% of patients. Local irritation and ulceration of penile epithelium in male patients and vulvovaginal ulceration in a female patient have also been reported.

Other

Foscarnet accumulates in teeth and bones of growing animals. Tooth enamel development has been affected in rats receiving foscarnet (the active ingredient contained in Foscavir)

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This information does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of information provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.