Foscarnet Sodium
Injection, Solution · Intravenous
Uses
Retinitis Foscarnet sodium injection is indicated for the treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS). Combination therapy with foscarnet sodium injection and ganciclovir is indicated for patients who have relapsed after monotherapy with either drug. SAFETY AND EFFICACY OF FOSCARNET SODIUM INJECTION HAVE NOT BEEN ESTABLISHED FOR TREATMENT OF OTHER CMV INFECTIONS (e.g., PNEUMONITIS, GASTROENTERITIS); CONGENITAL OR NEONATAL CMV DISEASE; OR NONIMMUNOCOMPROMISED INDIVIDUALS. Mucocutaneous Acyclovir Resistant HSV Infections Foscarnet sodium injection is indicated for the treatment of acyclovir-resistant mucocutaneous HSV infections in immunocompromised patients. SAFETY AND EFFICACY OF FOSCARNET SODIUM INJECTION HAVE NOT BEEN ESTABLISHED FOR TREATMENT OF OTHER HSV INFECTIONS (e.g., RETINITIS, ENCEPHALITIS); CONGENITAL OR NEONATAL HSV DISEASE; OR HSV IN NONIMMUNOCOMPROMISED INDIVIDUALS.
Dosage and administration
DOSAGE AND ADMINISTRATION CAUTION - DO NOT ADMINISTER FOSCARNET SODIUM INJECTION BY RAPID OR BOLUS INTRAVENOUS INJECTION. THE TOXICITY OF FOSCARNET SODIUM INJECTION MAY BE INCREASED AS A RESULT OF EXCESSIVE PLASMA LEVELS. CARE SHOULD BE TAKEN TO AVOID UNINTENTIONAL OVERDOSE BY CAREFULLY CONTROLLING THE RATE OF INFUSION. THEREFORE, AN INFUSION PUMP MUST BE USED. IN SPITE OF THE USE OF AN INFUSION PUMP, OVERDOSES HAVE OCCURRED. ADMINISTRATION Instructions for Administration and Preparation Foscarnet sodium injection is administered by controlled intravenous infusion, either by using a central venous line or with dilution by using a peripheral vein. The rate of controlled intravenous infusion must be no more than 1 mg/kg/minute. An individualized dose of foscarnet sodium injection should be calculated on the basis of body weight (mg/kg), renal function, indication of use and dosing frequency (refer to DOSAGE subsection). To reduce the risk of nephrotoxicity, creatinine clearance (mL/min/kg) should be calculated even if serum creatinine is within the normal range, and doses should be adjusted accordingly. An individualized dose at the required concentration (24 mg/mL or 12 mg/mL) for the route of administration (central line or peripheral line) needs to be aseptically prepared prior to dispensing. The standard 24 mg/mL solution may be used with or without dilution when using a central venous catheter for infusion. When a peripheral vein catheter is used, the 24 mg/mL injection must be diluted to a 12 mg/mL concentration with 5% dextrose in water or with a normal saline solution prior to administration to avoid local irritation of peripheral veins. Dilutions and/or removals of excess quantities should be accomplished under aseptic conditions. Solutions thus prepared should be used within 24 hours of first entry into a sealed bottle or infusion bag. Hydration Hydration may reduce the risk of nephrotoxicity. Clinically dehydrated patients should have their condition corrected before initiating foscarnet sodium injection therapy. It is recommended that 750 to 1,000 mL of normal saline or 5% dextrose solution should be given prior to the first infusion of foscarnet sodium injection to establish diuresis. With subsequent infusions, 750 to 1,000 mL of hydration fluid should be given with 90 mg/kg to 120 mg/kg of foscarnet sodium injection, and 500 mL with 40 mg/kg to 60 mg/kg of foscarnet sodium injection. Hydration fluid may need to be decreased if clinically warranted. Oral rehydration with similar regimens may be considered in certain patients. After the first dose, the hydration fluid should be administered concurrently with each infusion of foscarnet sodium injection. Compatibility With Other Solutions/Drugs Other drugs and supplements can be administered to a patient receiving foscarnet sodium injection. However, care must be taken to ensure that foscarnet sodium injection is only administered with normal saline or 5% dextrose solution and that no other drug or supplement is administered concurrently via the same catheter. Foscarnet has been reported to be chemically incompatible with 30% dextrose, amphotericin B, and solutions containing calcium such as Ringer’s lactate and TPN. Physical incompatibility with other intravenous drugs has also been reported including acyclovir sodium, ganciclovir, trimetrexate glucuronate, pentamidine isethionate, vancomycin, trimethoprim/sulfamethoxazole, diazepam, midazolam, digoxin, phenytoin, leucovorin, and proclorperazine. Because of foscarnet’s chelating properties, a precipitate can potentially occur when divalent cations are administered concurrently in the same catheter. Parenteral drug products must be inspected visually for particulate matter and discoloration prior to administration whenever the solution and container permit. Solutions that are discolored or contain particulate matter should not be used. Accidental Exposure Accidental skin and eye contact with foscarnet sodium solution may cause local irritation and burning sensation. If accidental contact occurs, the exposed area should be flushed with water. DOSAGE THE RECOMMENDED DOSAGE, FREQUENCY, OR INFUSION RATES SHOULD NOT BE EXCEEDED. ALL DOSES MUST BE INDIVIDUALIZED FOR PATIENTS’ RENAL FUNCTION. Induction Treatment The recommended initial dose of foscarnet sodium injection for patients with normal renal function is: For CMV retinitis patients, either 90 mg/kg (1-1/2 to 2 hour infusion) every twelve hours or 60 mg/kg (minimum one hour infusion) every eight hours over 2 to 3 weeks depending on clinical response. For acyclovir-resistant HSV patients, 40 mg/kg (minimum one hour infusion) either every 8 or 12 hours for 2 to 3 weeks or until healed. An infusion pump must be used to control the rate of infusion. Adequate hydration is recommended to establish a diuresis (see Hydration for recommendation ), both prior to and during treatment to minimize renal toxicity (see WARNINGS ), provided there are no clinical contraindications. Maintenance Treatment Following induction treatment the recommended maintenance dose of foscarnet sodium injection for CMV retinitis is 90 mg/kg/day to 120 mg/kg/day (individualized for renal function) given as an intravenous infusion over 2 hours. Because the superiority of the 120 mg/kg/day has not been established in controlled trials, and given the likely relationship of higher plasma foscarnet levels to toxicity, it is recommended that most patients be started on maintenance treatment with a dose of 90 mg/kg/day. Escalation to 120 mg/kg/day may be considered should early re-induction be required because of retinitis progression. Some patients who show excellent tolerance to foscarnet sodium injection may benefit from initiation of maintenance treatment at 120 mg/kg/day earlier in their treatment. An infusion pump must be used to control the rate of infusion with all doses.
Contraindications
Foscarnet sodium injection is contraindicated in patients with clinically significant hypersensitivity to foscarnet sodium.
Warnings
Renal Impairment THE MAJOR TOXICITY OF FOSCARNET SODIUM IS RENAL IMPAIRMENT (see ADVERSE REACTIONS section ). Renal impairment is most likely to become clinically evident during the second week of induction therapy, but may occur at any time during foscarnet sodium treatment. Renal function should be monitored carefully during both induction and maintenance therapy (see PATIENT MONITORING section ). Elevations in serum creatinine are usually, but not always, reversible following discontinuation or dose adjustment of foscarnet sodium. Safety and efficacy data for patients with baseline serum creatinine levels greater than 2.8 mg/dL or measured 24-hour creatinine clearances < 50 mL/min are limited. SINCE FOSCARNET SODIUM HAS THE POTENTIAL TO CAUSE RENAL IMPAIRMENT, DOSE ADJUSTMENT BASED ON SERUM CREATININE IS NECESSARY. Hydration may reduce the risk of nephrotoxicity. It is recommended that 750 mL to 1,000 mL of normal saline or 5% dextrose solution should be given prior to the first infusion of foscarnet sodium to establish diuresis. With subsequent infusions, 750 mL to 1,000 mL of hydration fluid should be given with 90 mg/kg to 120 mg/kg of foscarnet sodium, and 500 mL with 40 mg/kg to 60 mg/kg of foscarnet sodium. Hydration fluid may need to be decreased if clinically warranted. After the first dose, the hydration fluid should be administered concurrently with each infusion of foscarnet sodium. Mineral and Electrolyte Abnormalities Foscarnet sodium has been associated with changes in serum electrolytes including hypocalcemia, hypophosphatemia, hyperphosphatemia, hypomagnesemia, and hypokalemia (see ADVERSE REACTIONS section ). Foscarnet sodium may also be associated with a dose-related decrease in ionized serum calcium which may not be reflected in total serum calcium. This effect is likely to be related to chelation of divalent metal ions such as calcium by foscarnet. Patients should be advised to report symptoms of low ionized calcium such as perioral tingling, numbness in the extremities and paresthesias. Particular caution and careful management of serum electrolytes is advised in patients with altered calcium or other electrolyte levels before treatment and especially in those with neurologic or cardiac abnormalities and those receiving other drugs known to influence minerals and electrolytes (see PATIENT MONITORING and Drug Interactions sections ). Physicians should be prepared to treat these abnormalities and their sequelae such as tetany, seizures or cardiac disturbances. The rate of foscarnet sodium infusion may also affect the decrease in ionized calcium. Therefore, an infusion pump must be used for administration to prevent rapid intravenous infusion (see DOSAGE AND ADMINISTRATION section ). Slowing the infusion rate may decrease or prevent symptoms. Seizures Seizures related to mineral and electrolyte abnormalities have been associated with foscarnet sodium treatment (see WARNING section; Mineral and Electrolyte Abnormalities ). Several cases of seizures were associated with death. Cases of status epilepticus have been reported. Risk factors associated with seizures included impaired baseline renal function, low total serum calcium, and underlying CNS conditions. Hypersensitivity Serious acute hypersensitivity reactions (e.g., anaphylactic shock, urticaria, angioedema) have been reported post-marketing in patients receiving foscarnet sodium (see ADVERSE REACTIONS section ). If such an acute reaction occurs, therapy should be discontinued and appropriate medical therapy immediately instituted. QT prolongation and torsade de pointes Foscarnet sodium has been associated with prolongation of the QT interval, an ECG abnormality that has been associated with torsades de pointes, which has been reported during post-marketing surveillance for foscarnet sodium (see ADVERSE REACTIONS section ). Some of these patients had confounding risk factors such as underlying cardiac disease, electrolyte abnormalities and other concomitant medications. Use with caution in patients who have a history of QT prolongation, in patients who are taking medications known to prolong the QT interval (see PRECAUTIONS section ), in patients with electrolyte disturbances, or in patients who have other risk factors for QT prolongation. Electrocardiograms (ECGs) and measurement of electrolytes should be obtained prior to treatment initiation and periodically during treatment with foscarnet sodium.
Precautions
General Care must be taken to infuse solutions containing foscarnet sodium only into veins with adequate blood flow to permit rapid dilution and distribution to avoid local irritation (see DOSAGE AND ADMINISTRATION ). Local irritation and ulcerations of penile epithelium have been reported in male patients receiving foscarnet sodium, possibly related to the presence of drug in the urine. Cases of male and female genital irritation/ulceration have been reported in patients receiving foscarnet sodium. Adequate hydration with close attention to personal hygiene may minimize the occurrence of such events. Due to the sodium content of foscarnet sodium (240 micromoles (5.5 mg) of sodium per mL), avoid foscarnet sodium use when intravenous infusion of a large amount of sodium or water may not be tolerated (e.g., in patients with cardiomyopathy). Foscarnet sodium should also be avoided in patients on a controlled sodium diet. Hematopoietic System Anemia has been reported in 33% of patients receiving foscarnet sodium in controlled studies. Granulocytopenia has been reported in 17% of patients receiving foscarnet sodium in controlled studies; however, only 1% (2/189) were terminated from these studies because of neutropenia. Information for Patients CMV Retinitis: Patients should be advised that foscarnet sodium is not a cure for CMV retinitis, and that they may continue to experience progression of retinitis during or following treatment. They should be advised to have regular ophthalmologic examinations. Mucocutaneous Acyclovir-Resistant HSV Infections: Patients should be advised that foscarnet sodium is not a cure for HSV infections. While complete healing is possible, relapse occurs in most patients. Because relapse may be due to acyclovir-sensitive HSV, sensitivity testing of the viral isolate is advised. In addition, repeated treatment with foscarnet sodium has led to the development of resistance associated with poorer response. In the case of poor therapeutic response, sensitivity testing of the viral isolate also is advised. Effects on Ability to Drive and Use Machines: Adverse effects such as dizziness and convulsions may occur during foscarnet sodium therapy. Patients who experience seizures, dizziness, somnolence or other adverse reactions that could result in impairment, should be advised to avoid driving or operating machinery. General: Patients should be informed that the major toxicities of foscarnet are renal impairment, electrolyte disturbances, and seizures, and that dose modifications and possibly discontinuation may be required. The importance of close monitoring while on therapy must be emphasized. Patients should be advised of the importance of reporting to their physicians symptoms of perioral tingling, numbness in the extremities or paresthesias during or after infusion as possible symptoms of electrolyte abnormalities. Patients should also be advised to promptly report any cardiac symptoms. Should such symptoms occur, the infusion of foscarnet sodium should be stopped, appropriate laboratory samples for assessment of electrolyte concentrations obtained, and a physician consulted before resuming treatment. The rate of infusion must be no more than 1 mg/kg/minute. The potential for renal impairment may be minimized by accompanying foscarnet sodium administration with hydration adequate to establish and maintain a diuresis during dosing. Drug Interactions A possible drug interaction of foscarnet sodium and intravenous pentamidine has been described. Concomitant treatment of four patients in the United Kingdom with foscarnet sodium and intravenous pentamidine may have caused hypocalcemia; one patient died with severe hypocalcemia. Toxicity associated with concomitant use of aerosolized pentamidine has not been reported. Because foscarnet sodium can reduce serum levels of ionized calcium, extreme caution is advised when used concurrently with other drugs known to influence serum calcium levels (e.g., intravenous pentamidine). Renal impairment and symptomatic hypocalcemia have been observed during concurrent treatment with foscarnet sodium and intravenous pentamidine. Because of foscarnet’s tendency to cause renal impairment, the use of foscarnet sodium should be avoided in combination with potentially nephrotoxic drugs such as aminoglycosides, amphotericin B, cyclosporine, acyclovir, methotrexate, tacrolimus and intravenous pentamidine (see above) unless the potential benefits outweigh the risks to the patient. When diuretics are indicated, thiazides are recommended over loop diuretics because the latter inhibit renal tubular secretion, and may impair elimination of foscarnet sodium, potentially leading to toxicity. Abnormal renal function has been observed in clinical practice during the use of foscarnet sodium and ritonavir, or foscarnet sodium, ritonavir, and saquinavir (see DOSAGE and ADMINISTRATION ). Because of the risk of QT prolongation and the potential for torsades de pointes, the use of foscarnet sodium should be avoided in combination with agents known to prolong the QT interval including Class IA (e.g., quinidine or procainamide) or Class III (e.g., dofetilide, amiodarone, sotalol) antiarrhythmic agents, phenothiazines, tricyclic antidepressants, and certain macrolides and fluoroquinolones. Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenicity studies were conducted in rats and mice at oral doses of 500 mg/kg/day and 250 mg/kg/day. Oral bioavailability in unfasted rodents is < 20%. No evidence of oncogenicity was reported at plasma drug levels equal to 1/3 and 1/5, respectively, of those in humans (at the maximum recommended human daily dose) as measured by the area-under-the-time/concentration curve (AUC). Foscarnet sodium showed genotoxic effects in the BALB/3T3 in vitro transformation assay at concentrations greater than 0.5 mcg/mL and an increased frequency of chromosome aberrations in the sister chromatid exchange assay at 1,000 mcg/mL.
Side effects
(see WARNINGS section ). Approximately 33% of 189 patients with AIDS and CMV retinitis who received foscarnet sodium (60 mg/kg TID), without adequate hydration, developed significant impairment of renal function (serum creatinine ≥ 2.0 mg/dL). The incidence of renal impairment in subsequent clinical trials in which 1,000 mL of normal saline or 5% dextrose solution was given with each infusion of foscarnet sodium was 12% (34/280). Foscarnet sodium has been associated with changes in serum electrolytes including hypocalcemia (15% to 30%), hypophosphatemia (8% to 26%) and hyperphosphatemia (6%), hypomagnesemia (15% to 30%), and hypokalemia (16% to 48%) (see WARNINGS section ). The higher percentages were derived from those patients receiving hydration. Foscarnet sodium treatment was associated with seizures in 18/189 (10%) AIDS patients in the initial five controlled studies (see WARNINGS section ). Risk factors associated with seizures included impaired baseline renal function, low total serum calcium, and underlying CNS conditions predisposing the patient to seizures. The rate of seizures did not increase with duration of treatment. Three cases were associated with overdoses of foscarnet sodium (see OVERDOSAGE section ). In five controlled U.S. clinical trials the most frequently reported adverse events in patients with AIDS and CMV retinitis are shown in Table 9. These figures were calculated without reference to drug relationship or severity. TABLE 9: Adverse Events Reported in Five Controlled US Clinical Trials n = 189 n = 189 Fever 65% Abnormal Renal Function 27% Nausea 47% Vomiting 26% Anemia 33% Headache 26% Diarrhea 30% Seizures 10% From the same controlled studies, adverse events categorized by investigator as “severe” are shown in Table 10. Although death was specifically attributed to foscarnet sodium in only one case, other complications of foscarnet sodium (i.e. renal impairment, electrolyte abnormalities, and seizures) may have contributed to patient deaths (see WARNINGS section ). TABLE 10: Severe Adverse Events n = 189 Death 14% Abnormal Renal Function 14% Marrow Suppression 10% Anemia 9% Seizures 7% From the five initial U.S. controlled trials of foscarnet sodium, the following list of adverse events has been compiled regardless of causal relationship to foscarnet sodium. Evaluation of these reports was difficult because of the diverse manifestations of the underlying disease and because most patients received numerous concomitant medications. Incidence of 5% or Greater Body as a Whole: fever, fatigue, rigors, asthenia, malaise, pain, infection, sepsis, death Central and Peripheral Nervous System : headache, paresthesia, dizziness, involuntary muscle contractions, hypoesthesia, neuropathy, seizures including grand mal seizures (see WARNINGS ) Gastrointestinal System: anorexia, nausea, diarrhea, vomiting, abdominal pain Hematologic: anemia, granulocytopenia, leukopenia, neutropenia (see PRECAUTIONS ) Metabolic and Nutritional: mineral and electrolyte imbalances (see WARNINGS ) including hypokalemia, hypocalcemia, hypomagnesemia, hypophosphatemia, hyperphosphatemia Psychiatric: depression, confusion, anxiety Respiratory System: coughing, dyspnea Skin and Appendages: rash, increased sweating Urinary System: alterations in renal function including increased serum creatinine, decreased creatinine clearance, and abnormal renal function (see WARNINGS ) Special Senses: vision abnormalities Incidence between 1% and 5% Application Site: injection site pain, injection site inflammation Body as a Whole: back pain, chest pain (including reports of transient chest pain as part of infusion reactions), edema, influenza-like symptoms, bacterial infections, moniliasis, fungal infections, abscess Cardiovascular: hypertension, palpitations, ECG abnormalities including sinus tachycardia, first degree AV block and non-specific ST-T segment changes, hypotension, flushing, cerebrovascular disorder (see WARNINGS ) Central and Peripheral Nervous System: tremor, ataxia, dementia, stupor, generalized spasms, sensory disturbances, meningitis, aphasia, abnormal coordination, leg cramps, EEG abnormalities (see WARNINGS ) Gastrointestinal: constipation, dysphagia, dyspepsia, rectal hemorrhage, dry mouth, melena, flatulence, ulcerative stomatitis, pancreatitis Hematologic: thrombocytopenia, platelet abnormalities, thrombosis, white blood cell abnormalities, lymphadenopathy Liver and Biliary: abnormal A-G ratio, abnormal hepatic function, increased SGPT, increased SGOT Metabolic and Nutritional: hyponatremia, decreased weight, increased alkaline phosphatase, increased LDH, increased BUN, acidosis, cachexia, thirst Musculo-Skeletal: arthralgia, myalgia Neoplasms: lymphoma-like disorder, sarcoma Psychiatric: insomnia, somnolence, nervousness, amnesia, agitation, aggressive reaction, hallucination Respiratory System: pneumonia, sinusitis, pharyngitis, rhinitis, respiratory disorders, respiratory insufficiency, pulmonary infiltration, stridor, pneumothorax, hemoptysis, bronchospasm Skin and Appendages: pruritus, skin ulceration, seborrhea, erythematous rash, maculo-papular rash, skin discoloration Special Senses: taste perversions, eye abnormalities, eye pain, conjunctivitis Urinary System: albuminuria, dysuria, polyuria, urethral disorder, urinary retention, urinary tract infections, acute renal failure, nocturia, facial edema Selected adverse events occurring at a rate of less than 1% in the five initial U.S. controlled clinical trials of foscarnet sodium include: syndrome of inappropriate antidiuretic hormone secretion, pancytopenia, hematuria, dehydration, hypoproteinemia, increases in amylase and creatinine phosphokinase, cardiac arrest, coma, and other cardiovascular and neurologic complications. Selected adverse event data from the Foscarnet vs.
Drug interactions
Drug Interactions A possible drug interaction of foscarnet sodium and intravenous pentamidine has been described. Concomitant treatment of four patients in the United Kingdom with foscarnet sodium and intravenous pentamidine may have caused hypocalcemia; one patient died with severe hypocalcemia. Toxicity associated with concomitant use of aerosolized pentamidine has not been reported. Because foscarnet sodium can reduce serum levels of ionized calcium, extreme caution is advised when used concurrently with other drugs known to influence serum calcium levels (e.g., intravenous pentamidine). Renal impairment and symptomatic hypocalcemia have been observed during concurrent treatment with foscarnet sodium and intravenous pentamidine. Because of foscarnet’s tendency to cause renal impairment, the use of foscarnet sodium should be avoided in combination with potentially nephrotoxic drugs such as aminoglycosides, amphotericin B, cyclosporine, acyclovir, methotrexate, tacrolimus and intravenous pentamidine (see above) unless the potential benefits outweigh the risks to the patient. When diuretics are indicated, thiazides are recommended over loop diuretics because the latter inhibit renal tubular secretion, and may impair elimination of foscarnet sodium, potentially leading to toxicity. Abnormal renal function has been observed in clinical practice during the use of foscarnet sodium and ritonavir, or foscarnet sodium, ritonavir, and saquinavir (see DOSAGE and ADMINISTRATION ). Because of the risk of QT prolongation and the potential for torsades de pointes, the use of foscarnet sodium should be avoided in combination with agents known to prolong the QT interval including Class IA (e.g., quinidine or procainamide) or Class III (e.g., dofetilide, amiodarone, sotalol) antiarrhythmic agents, phenothiazines, tricyclic antidepressants, and certain macrolides and fluoroquinolones.
Pregnancy
Pregnancy There are no adequate and well-controlled studies of foscarnet sodium in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Animal Data: Foscarnet sodium did not adversely affect fertility and general reproductive performance in rats. The results of peri- and post-natal studies in rats were also negative. However, these studies used exposures that are inadequate to define the potential for impairment of fertility at human drug exposure levels. Daily subcutaneous doses up to 75 mg/kg administered to female rats prior to and during mating, during gestation, and 21 days post-partum caused a slight increase (< 5%) in the number of skeletal anomalies compared with the control group. Daily subcutaneous doses up to 75 mg/kg administered to rabbits and 150 mg/kg administered to rats during gestation caused an increase in the frequency of skeletal anomalies/variations. On the basis of estimated drug exposure (as measured by AUC), the 150 mg/kg dose in rats and 75 mg/kg dose in rabbits were approximately one-eighth (rat) and one-third (rabbit) the estimated maximal daily human exposure. These studies are inadequate to define the potential teratogenicity at levels to which women will be exposed.
Pediatric use
Pediatric Use The safety and effectiveness of foscarnet sodium in pediatric patients have not been established. Foscarnet sodium is deposited in teeth and bone and deposition is greater in young and growing animals. Foscarnet sodium has been demonstrated to adversely affect development of tooth enamel in mice and rats. The effects of this deposition on skeletal development have not been studied. Since deposition in human bone has also been shown to occur, it is likely that it does so to a greater degree in developing bone in pediatric patients. Administration to pediatric patients should be undertaken only after careful evaluation and only if the potential benefits for treatment outweigh the risks.
Overdosage
In controlled clinical trials performed in the United States, overdosage with foscarnet sodium was reported in 10 out of 189 patients. All 10 patients experienced adverse events and all except one made a complete recovery. One patient died after receiving a total daily dose of 12.5 g for three days instead of the intended 10.9 g. The patient suffered a grand mal seizure and became comatose. Three days later the patient expired with the cause of death listed as respiratory/cardiac arrest. The other nine patients received doses ranging from 1.14 times to 8 times their recommended doses with an average of 4 times their recommended doses. Overall, three patients had seizures, three patients had renal function impairment, four patients had paresthesias either in limbs or periorally, and five patients had documented electrolyte disturbances primarily involving calcium and phosphate. Overdose (up to 20 times the recommended dose) has been reported in post-marketing use of foscarnet sodium. Some of these post-marketing reports were relative overdoses in that the dose of foscarnet sodium had not been adjusted in patients with a reduced renal function. The pattern of adverse events associated with a foscarnet sodium overdose is consistent with the known adverse event profile of the drug. There is no specific antidote for foscarnet sodium overdose. Hemodialysis and hydration may be of benefit in reducing drug plasma levels in patients who receive an overdosage of foscarnet sodium, but the effectiveness of these interventions has not been evaluated. The patient should be observed for signs and symptoms of renal impairment and electrolyte imbalance. Medical treatment should be instituted if clinically warranted.
Description
The chemical name of foscarnet sodium is phosphonoformic acid, trisodium salt. Foscarnet sodium, USP is a white to almost white, crystalline powder containing 6 equivalents of water of hydration with an empirical formula of Na 3 CO 5 P.6H 2 O and a molecular weight of 300.04. The structural formula is: Foscarnet sodium injection has the potential to chelate divalent metal ions, such as calcium and magnesium, to form stable coordination compounds. Foscarnet sodium injection is a sterile, isotonic aqueous, clear, colorless solution for intravenous administration only. Each milliliter of foscarnet sodium injection contains 24 mg of foscarnet sodium hexahydrate in water for injection, USP. Hydrochloric acid may have been added to adjust the pH of the solution to 7.4. Foscarnet sodium injection contains no preservatives. 1
How supplied
Foscarnet Sodium Injection, 6000 mg/250 mL (24 mg/mL) is clear, colorless solution. It is available as follows: Strength Each Unit of Sale 6,000 mg/250 mL (24 mg/mL) NDC 70121-1744-1 1 Single-dose Intravenous Bag in an Overwrap NDC 70121-1744-7 Unit of 10 NDC 70121-1744-2 Unit of 12 Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Single-dose. Discard unused portion. Protect from excessive heat (above 40°C) and from freezing. If refrigerated or exposed to temperatures below the freezing point, precipitation may occur. By keeping the infusion bag at room temperature with repeated shaking, the precipitate can be brought into solution again. Foscarnet sodium injection should be used only if the infusion bag and its seal(s) are intact, a vacuum is present, and the solution is clear and colorless. Do not remove the infusion bag from the overwrap until ready for use. To report SUSPECTED ADVERSE REACTIONS, contact Amneal Pharmaceuticals LLC at 1-877-835-5472 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Manufactured by: Amneal Pharmaceuticals Pvt. Ltd. Mehsana 382165, INDIA Distributed by: Amneal Pharmaceuticals LLC Bridgewater, NJ 08807 Rev. 05-2026-04 1
Label text from the FDA structured product label by Amneal Pharmaceuticals LLC (revised Jun 25, 2026). Long sections are shortened; the complete label is on DailyMed.
Active ingredients
- Foscarnet Sodium in 7 products
Foscarnet Sodium NDC products (7)
| NDC | Strength & form | Labeler | Type |
|---|---|---|---|
| 70121-1744 | Foscarnet Sodium 24 mg/mL Injection | Amneal Pharmaceuticals LLC | ANDA |
| 43066-089 | Foscarnet Sodium 6000 mg/250mL Injection, Solution | Baxter Healthcare Corporation | ANDA |
| 65145-191 | Foscarnet Sodium 24 mg/mL Injection, Solution | Caplin Steriles Limited | ANDA |
| 68083-389 | Foscarnet Sodium 24 mg/mL Injection, Solution | Gland Pharma Limited | ANDA |
| 23155-771 | Foscarnet Sodium 24 mg/mL Injection, Solution | Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc. | ANDA |
| 0143-9192 | Foscarnet Sodium 24 mg/mL Injection, Solution | Hikma Pharmaceuticals USA Inc. | ANDA |
| 25021-189 | Foscarnet Sodium 24 mg/mL Injection, Solution | Sagent Pharmaceuticals | ANDA |
Frequently asked questions
What is Foscarnet Sodium used for?
Retinitis Foscarnet sodium injection is indicated for the treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS). Combination therapy with foscarnet sodium injection and ganciclovir is indicated for patients who have relapsed after monotherapy with either drug. SAFETY AND EFFICACY OF FOSCARNET SODIUM INJECTION HAVE NOT BEEN ESTABLISHED FOR TREATMENT OF OTHER CMV…
What are the side effects of Foscarnet Sodium?
(see WARNINGS section ). Approximately 33% of 189 patients with AIDS and CMV retinitis who received foscarnet sodium (60 mg/kg TID), without adequate hydration, developed significant impairment of renal function (serum creatinine ≥ 2.0 mg/dL). The incidence of renal impairment in subsequent clinical trials in which 1,000 mL of normal saline or 5% dextrose solution was given with each infusion of… See the full label for the complete list.
Who makes Foscarnet Sodium?
Foscarnet Sodium is listed by 7 labelers in the FDA NDC directory, including Amneal Pharmaceuticals LLC, Baxter Healthcare Corporation, Caplin Steriles Limited, Gland Pharma Limited.