Precautions for Cafcit
General
Apnea of prematurity is a diagnosis of exclusion. Other causes of apnea (e.g., central nervous system disorders, primary lung disease, anemia, sepsis, metabolic disturbances, cardiovascular abnormalities, or obstructive apnea) should be ruled out or properly treated prior to initiation of CAFCIT (caffeine citrate).
Caffeine is a central nervous system stimulant and in cases of caffeine overdose, seizures have been reported. CAFCIT should be used with caution in infants with seizure disorders.
The duration of treatment of apnea of prematurity in the placebo-controlled trial was limited to 10 to 12 days. The efficacy of CAFCIT for longer periods of treatment has not been established. Safety and efficacy of CAFCIT for use in the prophylactic treatment of sudden infant death syndrome (SIDS) or prior to extubation in mechanically ventilated infants have also not been established.
Cardiovascular
Although no cases of cardiac toxicity were reported in the placebo-controlled trial, caffeine has been shown to increase heart rate, left ventricular output, and stroke volume in published studies. Therefore, CAFCIT should be used with caution in infants with cardiovascular disease.
Renal And Hepatic Systems
CAFCIT should be administered with caution in infants with impaired renal or hepatic function. Serum concentrations of caffeine should be monitored and dose administration of CAFCIT should be adjusted to avoid toxicity in this population. (See CLINICAL PHARMACOLOGY, Elimination And Special Populations.)
Laboratory Tests
Prior to initiation of CAFCIT (caffeine citrate), baseline serum levels of caffeine should be measured in infants previously treated with theophylline, since preterm infants metabolize theophylline to caffeine. Likewise, baseline serum levels of caffeine should be measured in infants born to mothers who consumed caffeine prior to delivery, since caffeine readily crosses the placenta.
In the placebo-controlled clinical trial, caffeine levels ranged from 8 to 40 mg/L. A therapeutic plasma concentration range of caffeine could not be determined from the placebo-controlled clinical trial. Serious toxicity has been reported in the literature when serum caffeine levels exceed 50 mg/L. Serum concentrations of caffeine may need to be monitored periodically throughout treatment to avoid toxicity.
In clinical studies reported in the literature, cases of hypoglycemia and hyperglycemia have been observed. Therefore, serum glucose may need to be periodically monitored in infants receiving CAFCIT.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
In a 2-year study in Sprague-Dawley rats, caffeine (as caffeine base) administered in drinking water was not carcinogenic in male rats at doses up to 102 mg/kg or in female rats at doses up to 170 mg/kg (approximately 2 and 4 times, respectively, the maximum recommended intravenous loading dose for infants on a mg/m² basis). In an 18-month study in C57BL/6 mice, no evidence of tumorigenicity was seen at dietary doses up to 55 mg/kg (less than the maximum recommended intravenous loading dose for infants on a mg/m² basis).
Caffeine (as caffeine base) increased the sister chromatid exchange (SCE) SCE/cell metaphase (exposure time dependent) in an in vivo mouse metaphase analysis. Caffeine also potentiated the genotoxicity of known mutagens and enhanced the micronuclei formation (5-fold) in folate-deficient mice. However, caffeine did not increase chromosomal aberrations in in vitro Chinese hamster ovary cell (CHO) and human lymphocyte assays and was not mutagenic in an in vitro CHO/hypoxanthine guanine phosphoribosyltransferase (HGPRT) gene mutation assay, except at cytotoxic concentrations. In addition, caffeine was not clastogenic in an in vivo mouse micronucleus assay.
Caffeine (as caffeine base) administered to male rats at 50 mg/kg/day subcutaneously (approximately equal to the maximum recommended intravenous loading dose for infants on a mg/m² basis) for 4 days prior to mating with untreated females, caused decreased male reproductive performance in addition to causing embryotoxicity. In addition, long-term exposure to high oral doses of caffeine (3 g over 7 weeks) was toxic to rat testes as manifested by spermatogenic cell degeneration.
Pregnancy
Pregnancy Category C
Concern for the teratogenicity of caffeine is not relevant when administered to infants. In studies performed in adult animals, caffeine (as caffeine base) administered to pregnant mice as sustained release pellets at 50 mg/kg (less than the maximum recommended intravenous loading dose for infants on a mg/m² basis), during the period of organogenesis, caused a low incidence of cleft palate and exencephaly in the fetuses. There are no adequate and well-controlled studies in pregnant women.