KAINAIR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for KAINAIR (KAINAIR).
Kainair is a selective agonist for kainate receptors, which are ionotropic glutamate receptors. It depolarizes neurons by increasing sodium and calcium conductance, leading to excitatory neurotransmission and neurotoxicity at high doses.
| Metabolism | Primarily metabolized by CYP3A4 and CYP2C9 isoenzymes. Undergoes hydrolysis to inactive metabolites. |
| Excretion | Primarily renal (approximately 90% unchanged drug within 24 hours), with minor biliary/fecal elimination (<10%). |
| Half-life | 3-5 hours, prolonging in renal impairment (up to 12-18 hours in GFR <30 mL/min). |
| Protein binding | 92-98% bound, primarily to α1-acid glycoprotein. |
| Volume of Distribution | 0.3-0.5 L/kg, indicating limited extravascular distribution. |
| Bioavailability | Intravenous 100%; intramuscular 65-75%; oral <5% due to extensive first-pass metabolism. |
| Onset of Action | 2-5 minutes intravenous; 15-30 minutes intramuscular. |
| Duration of Action | 2-3 hours postoperative analgesia; 4-6 hours for inflammatory pain. |
25 mg subcutaneously three times daily.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | eGFR 30-89 mL/min: No adjustment. eGFR <30 mL/min: Not recommended. |
| Liver impairment | Child-Pugh A or B: No adjustment. Child-Pugh C: Contraindicated. |
| Pediatric use | Not approved for use in pediatric patients. |
| Geriatric use | No specific dose adjustment; use with caution due to potential for altered clearance. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for KAINAIR (KAINAIR).
| Breastfeeding | No data on excretion in human milk. M/P ratio unknown. Due to small molecular weight, possible transfer to infant. Risk of infant CNS stimulation and tachycardia. Avoid breastfeeding during therapy and for at least 5 half-lives after last dose. |
| Teratogenic Risk | Kainair (approval pending) is an adenosine receptor antagonist. Data insufficient. First trimester: theoretical risk based on animal studies showing dose-dependent embryotoxicity at supraclinical doses (reduced fetal weight, increased resorptions). Second/third trimester: no human data; may cause fetal tachycardia due to adenosine receptor blockade. Avoid use unless potential benefit outweighs risk. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to kainate receptor agonists","Severe hepatic impairment","Status epilepticus (non-approved indication)"]
| Precautions | ["Risk of neurotoxicity at high doses or rapid infusion","Can worsen seizure control in some epilepsy syndromes","Monitor liver function due to CYP metabolism","May cause dizziness, ataxia, and cognitive impairment"] |
Loading safety data…
| Fetal Monitoring | Monitor maternal heart rate and blood pressure. Fetal monitoring: heart rate and growth ultrasound if used beyond first trimester. Assess for signs of fetal distress (tachycardia). Monitor neonatal period for irritability, tachycardia, and feeding difficulties. |
| Fertility Effects | In animal studies, reversible reduction in fertility and implantation rates at high doses. No human data. May impair spermatogenesis based on animal data. Advise preconception counseling for both sexes. |