CAM-METRAZINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CAM-METRAZINE (CAM-METRAZINE).
CAM-METRAZINE (metformin and rosiglitazone combination) improves glycemic control by decreasing hepatic glucose production (metformin, AMPK activation) and increasing insulin sensitivity in peripheral tissues (rosiglitazone, PPARγ agonist).
| Metabolism | Metformin: excreted unchanged in urine; no hepatic metabolism. Rosiglitazone: extensively metabolized via CYP2C8, minor via CYP2C9. |
| Excretion | Primarily renal (80-90% unchanged) via glomerular filtration and tubular secretion; minor biliary/fecal (5-10%). |
| Half-life | Terminal elimination half-life is 6-8 hours in adults with normal renal function; prolonged to 12-20 hours in moderate renal impairment (CrCl <50 mL/min), requiring dose adjustment. |
| Protein binding | 35-45% bound primarily to serum albumin; also binds alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.5-0.8 L/kg, indicating moderate distribution into total body water; crosses the blood-brain barrier with CSF levels 10-20% of plasma. |
| Bioavailability | Oral: 60-70% due to first-pass metabolism; Intravenous: 100%; Intramuscular: 85-95%. |
| Onset of Action | Intravenous: 2-5 minutes; Oral: 30-45 minutes; Intramuscular: 10-15 minutes. |
| Duration of Action | 4-6 hours after single dose via IV/IM; oral dosing requires 6-8 hour intervals due to shorter duration. |
Initial dose: 30 mg orally once daily; may increase to 60 mg orally once daily after 2 weeks, then to 90 mg orally once daily after another 2 weeks. Maximum dose: 90 mg/day.
| Dosage form | TABLET |
| Renal impairment | eGFR 30-89 mL/min: No adjustment. eGFR 15-29 mL/min: Reduce dose by 50%; maximum 45 mg/day. eGFR <15 mL/min or dialysis: Not recommended. |
| Liver impairment | Child-Pugh Class A: No adjustment. Child-Pugh Class B: Reduce dose by 50%; maximum 45 mg/day. Child-Pugh Class C: Not recommended. |
| Pediatric use | Not approved for patients under 18 years; safety and efficacy not established. |
| Geriatric use | Start at 15 mg orally once daily; titrate slowly based on response and tolerability. Monitor renal function closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CAM-METRAZINE (CAM-METRAZINE).
| Breastfeeding | Camphor is excreted in breast milk and may cause neonatal apnea and seizures. M/P ratio not established. Contraindicated during breastfeeding. |
| Teratogenic Risk | CAM-METRAZINE contains camphor and metrazine (pentylenetetrazol). Camphor is teratogenic in animal studies; first-trimester exposure may cause neural tube defects and cleft palate. Second and third trimester risks include fetal CNS depression and respiratory distress. Avoid in pregnancy unless benefit outweighs risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
Rosiglitazone: Thiazolidinediones may cause or exacerbate congestive heart failure; not recommended in patients with NYHA Class III/IV heart failure.
| Serious Effects |
["Renal impairment (e.g., serum creatinine ≥1.5 mg/dL in males, ≥1.4 mg/dL in females, or abnormal creatinine clearance)","Acute or chronic metabolic acidosis","Congestive heart failure (NYHA Class III or IV)","History of hypersensitivity to metformin, rosiglitazone, or any components","Diabetic ketoacidosis (treated with insulin)"]
| Precautions | ["Lactic acidosis (metformin, contraindicated if renal impairment)","Congestive heart failure (rosiglitazone)","Hepatotoxicity","Edema","Weight gain","Hypoglycemia when combined with insulin or sulfonylureas","Ovarian hyperstimulation (premenopausal anovulatory women)","Fracture risk (women)"] |
| Food/Dietary | Avoid caffeine-containing foods/beverages (coffee, tea, cola) as they may increase stimulant effects. No significant food interactions with camphor or pentylenetetrazol. |
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| Monitor maternal vital signs (BP, HR, respiratory rate) and CNS status. Fetal monitoring (ultrasound for anomalies if first-trimester exposure; non-stress test in third trimester). Assess neonatal respiratory and neurological function at birth. |
| Fertility Effects | Camphor may impair spermatogenesis in males and disrupt menstrual cycles in females. Pentylenetetrazol may affect gamete quality due to CNS stimulation. Use with caution in couples planning conception. |
| Clinical Pearls | CAM-METRAZINE is a combination of camphor and metrazol (pentylenetetrazol) used historically as a central nervous system stimulant for respiratory depression. Due to narrow therapeutic index and risk of seizures, it is rarely used in modern practice. Monitor for prodromal signs of CNS toxicity (twitching, confusion). Contraindicated in seizure disorders, cardiac arrhythmias, and hypertension. |
| Patient Advice | Take exactly as prescribed; do not exceed recommended dose to avoid risk of seizures. · Avoid driving or operating heavy machinery until you know how this medication affects you, as it may cause dizziness or confusion. · Report any muscle twitching, confusion, or rapid heartbeat to your healthcare provider immediately. · Do not consume alcohol or other CNS depressants while taking this medication. · Store at room temperature away from light and moisture. |