Somatropininteractions

Table 7 includes a list of drugs with clinically important drug interactions when administered concomitantly with ZOMACTON and instructions for preventing or managing them.

Table 7: Clinically Important Drug Interactions with ZOMACTON Glucocorticoids Clinical Impact: Microsomal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD-1) is required for conversion of cortisone to its active metabolite, cortisol, in hepatic and adipose tissue. ZOMACTON inhibits 11βHSD-1. Consequently, individuals with untreated GH deficiency have relative increases in 11βHSD-1 and serum cortisol. Initiation of ZOMACTON may result in inhibition of 11βHSD-1 and reduced serum cortisol concentrations.

Intervention: Patients treated with glucocorticoid replacement for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of ZOMACTON.

Examples: Cortisone acetate and prednisone may be affected more than others since conversion of these drugs to their biologically active metabolites is dependent on the activity of 11βHSD-1. Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment Clinical Impact: Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment may attenuate the growth promoting effects of ZOMACTON in pediatric patients.

Intervention: Carefully adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatments to avoid both hypoadrenalism and an inhibitory effect on growth. Cytochrome P450-Metabolized Drugs Clinical Impact: Limited published data indicate that somatropin treatment increases cytochrome P450 (CP450)-mediated antipyrine clearance. ZOMACTON may alter the clearance of compounds known to be metabolized by CP450 liver enzymes.

Intervention: Careful monitoring is advisable when ZOMACTON is administered in combination with drugs metabolized by CP450 liver enzymes.

Oral Estrogen Clinical Impact: Oral estrogens may reduce the serum IGF-1 response to ZOMACTON.

Intervention: Patients receiving oral estrogen replacement may require greater ZOMACTON dosages. Insulin and/or Other Hypoglycemic Agents Clinical Impact: Treatment with ZOMACTON may decrease insulin sensitivity, particularly at higher doses.

Intervention: Patients with diabetes mellitus may require adjustment of their doses of insulin and/or other hypoglycemic agents.

Glucocorticoids: Patients treated with glucocorticoid for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of ZOMACTON Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment: Adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatment to avoid both hypoadrenalism and an inhibitory effect on growth.

Cytochrome P450-Metabolized Drugs: ZOMACTON may alter the clearance. Monitor carefully if used with ZOMACTON Oral Estrogen: Larger doses of ZOMACTON may be required Insulin and/or Other Hypoglycemic Agents: Dose adjustment of insulin or hypoglycemic agent may be required