Precautions for Albuterol Sulfate Tablets
General
Albuterol, as with all sympathomimetic amines, should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, cardiac arrhythmias, and hypertension; in patients with convulsive disorders, hyperthyroidism, or diabetes mellitus; and in patients who are unusually responsive to sympathomimetic amines. Clinically significant changes in systolic and diastolic blood pressure have been seen in individual patients and could be expected to occur in some patients after use of any beta-adrenergic bronchodilator.
Large doses of intravenous albuterol have been reported to aggravate preexisting diabetes mellitus and ketoacidosis. As with other beta-agonists, albuterol may produce significant hypokalemia in some patients, possibly through intracellular shunting, which has the potential to produce adverse cardiovascular effects. The decrease is usually transient, not requiring supplementation.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
In a 2-year study in Sprague-Dawley rats, albuterol sulfate caused a significant dose-related increase in the incidence of benign leiomyomas of the mesovarium at dietary doses of 2, 10, and 50 mg/kg (approximately 1/2 , 3 and 15 times, respectively, the maximum recommended daily oral dose for adults on a mg/m2 basis, or, 2/5, 2 and 10 times, respectively, the maximum recommended daily oral dose for children on a mg/m2 basis). In another study this effect was blocked by the coadministration of propranolol, a non-selective beta-adrenergic antagonist.
In an 18-month study in CD-1 mice albuterol sulfate showed no evidence of tumorigenicity at dietary doses of up to 500 mg/kg, (approximately 65 times the maximum recommended daily oral dose for adults on a mg/m2 basis, or, approximately 50 times the maximum recommended daily oral dose for children on a mg/m2 basis). In a 22-month study in the Golden hamster albuterol sulfate showed no evidence of tumorigenicity at dietary doses of up to 50 mg/kg, (approximately 8 times the maximum recommended daily oral dose for adults on a mg/m2 basis, or, approximately 7 times the maximum recommended daily oral dose for children on a mg/m2 basis).
Albuterol sulfate was not mutagenic in the Ames test with or without metabolic activation using tester strains S. typhimurium TA1537, TA1538, and TA98 or E. Coli WP2, WP2uvrA, and WP67. No forward mutation was seen in yeast strain S. cerevisiae S9 nor any mitotic gene conversion in yeast strain S. cerevisiae JD1 with or without metabolic activation. Fluctuation assays in S. typhimurium TA98 and E. Coli WP2, both with metabolic activation, were negative. Albuterol sulfate was not clastogenic in a human peripheral lymphocyte assay or in an AH1 strain mouse micronucleus assay at intraperitoneal doses of up to 200 mg/kg.
Reproduction studies in rats demonstrated no evidence of impaired fertility at oral doses up to 50 mg/kg (approximately 15 times the maximum recommended daily oral dose for adults on a mg/m2 basis).
Pregnancy
Teratogenic Effects
Pregnancy Category C
Albuterol has been shown to be teratogenic in mice. A study in CD-1 mice at subcutaneous (sc) doses of 0.025, 0.25, and 2.5 mg/kg, (approximately 3/1000, 3/100, and 3/10 times, respectively, the maximum recommended daily oral dose for adults on a mg/m2 basis), showed cleft palate formation in 5 of 111 (4.5%) fetuses at 0.25 mg/kg and in 10 of 108 (9.3%) fetuses at 2.5 mg/kg. The drug did not induce cleft palate formation at the lowest dose, 0.025 mg/kg. Cleft palate also occurred in 22 of 72 (30.5%) fetuses from females treated with 2.5 mg/kg of isoproterenol (positive control) subcutaneously (approximately 3/10 times the maximum recommended daily oral dose for adults on a mg/m2 basis).
A reproduction study in Stride Dutch rabbits revealed cranioschisis in 7 of 19 (37%) fetuses when albuterol was administered orally at a 50 mg/kg dose (approximately 25 times the maximum recommended daily oral dose for adults on a mg/m2 basis).
There are no adequate and well-controlled studies in pregnant women. Albuterol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
During worldwide marketing experience, various congenital anomalies, including cleft palate and limb defects, have been rarely reported in the offspring of patients being treated with albuterol. Some of the mothers were taking multiple medications during their pregnancies. No consistent pattern of defects can be discerned, and a relationship between albuterol use and congenital anomalies has not been established.
Use In Labor And Delivery
Because of the potential for beta-agonist interference with uterine contractility, use of albuterol tablets for relief of bronchospasm during labor should be restricted to those patients in whom the benefits clearly outweigh the risk.
Tocolysis
Albuterol has not been approved for the management of preterm labor. The benefit/risk ratio when albuterol is administered for tocolysis has not been established. Serious adverse reactions, including maternal pulmonary edema, have been reported during or following treatment of premature labor with beta2 -agonists, including albuterol.
Nursing Mothers
It is not known whether this drug is excreted in human milk. Because of the potential for tumorigenicity shown for albuterol in animal studies, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Pediatric Use
Safety and effectiveness in children below 6 years of age have not been established.