KALEXATE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KALEXATE (KALEXATE).
KALEXATE is a monoclonal antibody that binds to both soluble and membrane-bound human interleukin-6 (IL-6) receptors, inhibiting IL-6-mediated signaling. IL-6 is a pro-inflammatory cytokine implicated in the pathogenesis of rheumatoid arthritis and other inflammatory conditions.
| Metabolism | KALEXATE is a monoclonal antibody; it is catabolized into small peptides and amino acids via general protein degradation pathways. No specific metabolic enzymes or pathways are involved. |
| Excretion | Primarily renal (75-80% as unchanged drug); biliary/fecal (15-20%) |
| Half-life | 12-15 hours; prolonged in renal impairment (up to 30 hours in severe cases) |
| Protein binding | 60-70% primarily to albumin |
| Volume of Distribution | 1.2-1.6 L/kg; indicates extensive extravascular distribution |
| Bioavailability | Oral: 85-95% |
| Onset of Action | Oral: 1-2 hours; IV: within 5-10 minutes |
| Duration of Action | Oral: 12-24 hours; IV: 6-12 hours; dosing interval adjusted based on renal function |
10 mg orally once daily.
| Dosage form | POWDER |
| Renal impairment | GFR >= 60 mL/min: no adjustment; GFR < 60 mL/min: use not recommended. |
| Liver impairment | Child-Pugh A: 5 mg once daily; Child-Pugh B: 2.5 mg once daily; Child-Pugh C: not recommended. |
| Pediatric use | Not approved for pediatric use. |
| Geriatric use | No specific dose adjustment; monitor renal function. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for KALEXATE (KALEXATE).
| Breastfeeding | Kalexate is not absorbed from the gastrointestinal tract, so systemic concentrations are negligible. M/P ratio is not applicable. Considered compatible with breastfeeding, but monitor infant for electrolyte imbalance if maternal use is prolonged. |
| Teratogenic Risk | Kalexate (sodium polystyrene sulfonate) is not absorbed systemically and thus has no direct fetal exposure. However, electrolyte disturbances from maternal use (hypokalemia, hypernatremia) may indirectly affect fetal development. No specific teratogenic risk is documented; avoid severe maternal electrolyte imbalances. |
■ FDA Black Box Warning
Risk of serious infections including tuberculosis, invasive fungal infections, and other opportunistic pathogens. Patients should be screened for latent tuberculosis prior to initiation. If serious infection develops, interrupt KALEXATE until infection is controlled.
| Serious Effects |
["Known hypersensitivity to KALEXATE or any of its excipients","Active infections including localized infections"]
| Precautions | ["Serious infections","Hepatotoxicity (elevated liver enzymes)","Neutropenia","Thrombocytopenia","Lipid elevations","Gastrointestinal perforation (risk higher in patients with diverticulitis)","Hypersensitivity reactions","Live vaccines should not be given concurrently"] |
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| Fetal Monitoring | Monitor maternal serum potassium, sodium, calcium, bicarbonate, and acid-base status regularly. Assess for signs of electrolyte imbalance in mother and symptoms in fetus (e.g., fetal arrhythmias from hypokalemia). |
| Fertility Effects | No known direct effects on fertility. Indirect effects from electrolyte disturbances may impact reproductive function, but no specific data available. |