Dosing and uses of Lithostat (acetohydroxamic acid)
Adult dosage forms and strengths
tablet
- 250mg
Chronic Urinary Tract Infection
Indicated for chronic UTS caused by urea-splitting organisms
Initial: 12 mg/kg/day PO divided q6 -8hr on empty stomach
Maintenance: 250 mg PO q6-8hr; not to exceed 1.5 g/day
Renal Impairment
SCr 1.8-2.5 mg/dL [159-221 micromoles/L]: Dose q12hr; not to exceed 1 g/day
SCr >2.5 mg/dL [>221 micromoles/L]: Not recommended
Pediatric dosage forms and strengths
tablet
- 250mg
Chronic Urinary Tract Infection
Indicated for chronic UTS caused by urea-splitting organisms
Initial: 10 mg/kg/day PO divided q6-8hr on empty stomach; titrate to patient response
Geriatric dosage forms and strengths
Chronic Urinary Tract Infection
Indicated for chronic UTS caused by urea-splitting organisms
Initial: 12 mg/kg/day PO divided q6-8hr on empty stomach
Maintenance: 250 mg PO q6-8hr; not to exceed 1.5 g/day
Lithostat (acetohydroxamic acid) adverse (side) effects
>10%
Mild headache; first 48 hours (30%)
Anorexia (20-25%)
Malaise (20-25%)
Nausea (20-25%)
Vomiting (20-25%)
Anxiety (20%)
Confused (20%)
Depression (20%)
Involuntary quivering (20%)
Hemolytic anemia (15%)
<1%
Alopecia
Blood clot
Macular rash
Phlebitis
Warnings
Contraindications
Hypersensitivity
Pts. amenable to definitive surgery & antimicrobial agents, infection by non-urease producing organisms, urinary infections controlled by culture-specific antimicrobials, severe renal impairment (CrCl <20 mL/min &/or serum creatinine>2.5 mg/dL [221 umol/L]), inadequate contraception (females), pregnancy
Cautions
Always use with appropriate antimicrobial treatment
Potential teratogen
Pregnancy and lactation
Pregnancy category: X
Lactation: excretion in breast milk unknown/not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Lithostat (acetohydroxamic acid)
Mechanism of action
Inhibits bacterial urease, decreasing ammonia production
Does not acidify urine or have direct antibacterial effect
Pharmacokinetics
Absorption: Well-absorbed
Peak Plasma Time: 15 min -1 hr
Excretion: Urine (55% of oral dose unchanged)
