Search
foscarnet (Foscavir)
Tradename: Foscavir. A virustatic agent.
Indications:
- CMV retinitis:
1) indications a patients with ganciclovir-resistant CMV
b) patients who cannot tolerate ganciclovir
2) induction therapy
-> 60 mg/kg every 8 hours or 90 mg/kg every 12 hours IV for 2-3 weeks
3) maintenance therapy: 90-120 mg/kg/day
4) foscarnet is administered IV as a 1-2 hour infusion
5) daily infusions of normal saline (1 liter) may reduce nephrotoxicity
- Varicella zoster [5]
- Herpes simplex
Dosage: Injection: 24 mg/mL (250 mL, 500 mL)
Dosage adjustment in renal failure: (maintenance)
- 25 mg/kg every 8 hours GFR > 50 mL/min
- 15 mg/kg every 8 hours GFR 10-50 mL/min
- 6 mg/kg every 8 hours GFR < 10 mL/min
Pharmacokinetics:
1) elimination 1/2life 3 hours
2) terminal 1/2life of 18-88 hours
Adverse effects:
1) common (> 10%)
- fever, nausea, anemia, diarrhea, renal insufficiency, headache, seizures
2) less common (1-10%)
- fevers, rigors, asthenia, malaise, pain at site of injection, sepsis, paresthesias, dizziness, involuntary muscle contractions, hypoesthesia, neuropathy, anorexia, granulocytopenia, leukopenia, electrolyte disorder, depression, confusion, anxiety, coughing, dyspnea, rash, increased sweating, visual disturbance
3) uncommon (< 1%)
- hypothermia, peripheral edema, ascites, syncope, substernal chest pain, abnormal crying, malignant hyperpyrexia, heart failure, bradycardia, arrhythmias, vertigo, coma, abnormal gait, hypertonia, dyskinesia, vocal cord paralysis, speech disorder, cerebral edema, nystagmus, gynecomastia
4) other [4]
- hypocalcemia (decreased ionized calcium)
- hypomagnesemia
- hypophosphatemia
Test interactions:
- decreased serum gonadotropins
Mechanism of action:
1) pyrophosphate that inhibits Herpesvirus DNA polymerase
2) does NOT require intracellular phosphorylation for activity
3) active against viruses deficient in thymidine kinase
Interactions
drug interactions
General
antiviral agent
pyrophosphate
Properties
MISC-INFO: elimination route KIDNEY
pregnancy-category C
safety in lactation ?
Database Correlations
PUBCHEM correlations
References
- The Pharmacological Basis of Therapeutics, 9th ed.
Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- Manual of Medical Therapeutics, 28th ed, Ewald &
McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 294
- Kaiser Permanente Northern California Regional Drug
Formulary, 1998
- Medical Knowledge Self Assessment Program (MKSAP) 11, American
College of Physicians, Philadelphia 1998
- Deprecated Reference
- Department of Veterans Affairs, VA National Formulary