Drug Interactions between Acid Controller Complete Dual Action and vamorolone

ADJUST DOSING INTERVAL: Administration with food may increase the absorption of calcium. However, foods high in oxalic acid (spinach or rhubarb), or phytic acid (bran and whole grains) may decrease calcium absorption.

MANAGEMENT: Calcium may be administered with food to increase absorption. Consider withholding calcium administration for at least 2 hours before or after consuming foods high in oxalic acid or phytic acid.

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of vamorolone. The proposed mechanism is inhibition of CYP450 3A4-mediated metabolism in the gut wall by certain compounds present in grapefruit. The metabolism of vamorolone is mediated by the isoenzymes CYP450 3A4/5, and CYP450 2C8, and uridine diphosphate glucuronosyltransferases (UGT) 1A3, 2B7, and 2B17. In general, the effect of grapefruit juice is concentration-, dose-, and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Increased systemic exposure to vamorolone may increase the risk of corticosteroid adverse effects such as hypercorticism, hyperglycemia, adrenal suppression, immunosuppression, hypertension, salt and water retention, electrolyte abnormalities, behavioral and mood disturbances, posterior subcapsular cataracts, glaucoma, bone loss, and growth retardation in children and adolescents.

MANAGEMENT: Until further information is available, it may be advisable for patients to avoid the consumption of large amounts of grapefruit and grapefruit juice during vamorolone therapy unless otherwise directed by their doctor, as the interaction is unreliable and subject to a high degree of interpatient variation. If coadministration is considered necessary, patients should be closely monitored for signs and symptoms of corticosteroid adverse effects. Patients should also be monitored for signs and symptoms of hypercorticism such as acne, striae, thinning of the skin, easy bruising, moon facies, dorsocervical "buffalo" hump, truncal obesity, increased appetite, acute weight gain, edema, hypertension, hirsutism, hyperhidrosis, proximal muscle wasting and weakness, glucose intolerance, exacerbation of preexisting diabetes, and depression. Signs and symptoms of adrenal insufficiency include anorexia, hypoglycemia, nausea, vomiting, weight loss, muscle wasting, fatigue, weakness, dizziness, postural hypotension, depression, and adrenal crisis manifested as an inability to respond to stress (e.g., illness, infection, surgery, trauma). Consultation with product labeling for specific recommendations is advisable.

H2 antagonists may reduce the clearance of nicotine. Cimetidine, 600 mg given twice a day for two days, reduced clearance of an intravenous nicotine dose by 30%. Ranitidine, 300 mg given twice a day for two days, reduced clearance by 10%. The clinical significance of this interaction is not known. Patients should be monitored for increased nicotine effects when using the patches or gum for smoking cessation and dosage adjustments should be made as appropriate.