SOMATROPIN Drug Interactions: What You Need to Know

INTERACTIONS Inhibition of 11 β-Hydroxysteroid Dehydrogenase Type 1: May require the initiation of glucocorticoid replacement therapy. Patients treated with glucocorticoid replacement for previously diagnosed hypoadrenalism may require an increase in their maintenance doses ( 7.1 , 7.2 ). Glucocorticoid replacement: Should be carefully adjusted ( 7.2 ). Cytochrome P450- Metabolized Drugs: Monitor carefully if used with somatropin ( 7.3 ). Oral estrogen: Larger doses of somatropin may be required in women ( 7.4 ). Insulin and/or other hypoglycemic agents: May require adjustment ( 7.5 ). 7.1 11 β-Hydroxysteroid Dehydrogenase Type 1 (11βHSD-1) The microsomal enzyme 11βHSD-1 is required for conversion of cortisone to its active metabolite, cortisol, in hepatic and adipose tissue. Growth hormone (GH) and somatropin inhibit 11βHSD-1. Consequently, individuals with untreated GH deficiency have relative increases in 11βHSD-1 and serum cortisol. Introduction of somatropin treatment may result in inhibition of 11βHSD-1 and reduced serum cortisol concentrations. As a consequence, previously undiagnosed central (secondary) hypoadrenalism may be unmasked and glucocorticoid replacement may be required in patients treated with somatropin. In addition, patients treated with glucocorticoid replacement for previously diagnosed hypoadrenalism may require an increase in their maintenance or stress doses following initiation of somatropin treatment; this may be especially true for patients treated with cortisone acetate and prednisone since conversion of these drugs to their biologically active metabolites is dependent on the activity of 11βHSD-1.

7.2 Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment may attenuate the growth-promoting effects of somatropin in children. Therefore, glucocorticoid replacement therapy should be carefully adjusted in children with concomitant GH and glucocorticoid deficiency to avoid both hypoadrenalism and an inhibitory effect on growth. The use of Nutropin AQ in patients with Chronic Kidney Disease (CKD) requiring glucocorticoid therapy has not been evaluated. Concomitant glucocorticoid therapy may inhibit the growth promoting effect of Nutropin AQ. Therefore, if glucocorticoid replacement is required for CKD, the glucocorticoid dose should be carefully adjusted to avoid an inhibitory effect on growth. In the clinical trials there was no evidence of drug interactions with Nutropin and commonly used drugs used in the management of CKD.

7.3 Cytochrome P450 (CYP450)-Metabolized Drugs Limited published data indicate that somatropin treatment increases CYP450-mediated antipyrine clearance in man. These data suggest that somatropin administration may alter the clearance of compounds known to be metabolized by CYP450 liver enzymes (e.g., corticosteroids, sex steroids, anticonvulsants, cyclosporine). Careful monitoring is advisable when somatropin is administered in combination with other drugs known to be metabolized by CYP450 liver enzymes. However, formal drug interaction studies have not been conducted.

7.4 Oral Estrogen Because oral estrogens may reduce insulin-like growth factor (IGF-1) response to somatropin treatment, girls and women receiving oral estrogen replacement may require greater somatropin dosages <span class="opacity-50 text-xs">[see Dosage and Administration (2.2) ]</span> .

7.5 Insulin and/or Oral/Injectable Hypoglycemic Agents In patients with diabetes mellitus requiring drug therapy, the dose of insulin and/or oral/injectable hypoglycemic agents may require adjustment when somatropin therapy is initiated <span class="opacity-50 text-xs">[see Warnings and Precautions (5.4) ]</span> .

Acute critical illness ( 4 ). Children with Prader-Willi syndrome (PWS) who are severely obese or have severe respiratory impairment – reports of sudden death ( 4 ). Active malignancy ( 4 ). Hypersensitivity to somatropin or excipients ( 4 ). Active proliferative or severe non-proliferative diabetic retinopathy ( 4 ). Children with closed epiphysis ( 4 ).

Acute Critical Illness

Treatment with pharmacologic amounts of somatropin is contraindicated in patients with acute critical illness due to complications following open heart surgery, abdominal surgery or multiple accidental trauma, or those with acute respiratory failure [see Warnings and Precautions (5.1) ]. Prader-Willi Syndrome (PWS) in Children Somatropin is contraindicated in patients with PWS who are severely obese, have a history of upper airway obstruction or sleep apnea, or have severe respiratory impairment. There have been reports of sudden death when somatropin was used in such patients. Nutropin AQ is not indicated for the treatment of pediatric patients who have growth failure due to genetically confirmed PWS [see Warnings and Precautions (5.2) ] .

Active

Malignancy In general, somatropin is contraindicated in the presence of active malignancy. Any pre-existing malignancy should be inactive and its treatment complete prior to instituting therapy with somatropin. Somatropin should be discontinued if there is evidence of recurrent activity. Since growth hormone deficiency (GHD) may be an early sign of the presence of a pituitary tumor (or, rarely, other brain tumors), the presence of such tumors should be ruled out prior to initiation of treatment. Somatropin should not be used in patients with any evidence of progression or recurrence of an underlying intracranial tumor [see Warnings and Precautions (5.3) ].

Hypersensitivity

Nutropin AQ is contraindicated in patients with a known hypersensitivity to somatropin or any of its excipients. Systemic hypersensitivity reactions have been reported with postmarketing use of somatropin products [see Warnings and Precautions (5.6) ].

Diabetic Retinopathy

Somatropin is contraindicated in patients with active proliferative or severe non-proliferative diabetic retinopathy.

Closed Epiphysis

Somatropin should not be used for growth promotion in pediatric patients with closed epiphysis.

AND PRECAUTIONS

• Acute Critical Illness: Potential benefit of treatment continuation should be weighed against the potential risk ( 5.1 )
• Prader-Willi Syndrome in children: Evaluate for signs of upper airway obstruction and sleep apnea before initiation of treatment. Discontinue treatment if these signs occur ( 5.2 )
• Neoplasm: Monitor patients with preexisting tumors for progression or recurrence. Increased risk of a second neoplasm in childhood cancer survivors treated with somatropin - in particular meningiomas in patients treated with radiation to the head for their first neoplasm ( 5.3 )
• Impaired Glucose Tolerance and Diabetes Mellitus: May be unmasked. Periodically monitor glucose levels in all patients. Doses of concurrent antihyperglycemic drugs in diabetics may require adjustment ( 5.4 )
• Intracranial Hypertension: Exclude preexisting papilledema. May develop and is usually reversible after discontinuation or dose reduction ( 5.5 )
• Hypersensitivity: Serious hypersensitivity reactions may occur. In the event of an allergic reaction, seek prompt medical attention ( 5.6 )
• Fluid Retention (i.e., edema, arthralgia, carpal tunnel syndrome - especially in adults): May occur frequently. Reduce dose as necessary ( 5.7 )
• Hypoadrenalism: Monitor patients for reduced serum cortisol levels and/or need for glucocorticoid dose increases in those with known hypoadrenalism ( 5.8 )
• Hypothyroidism: May first become evident or worsen ( 5.9 )
• Slipped Capital Femoral Epiphysis: May develop. Evaluate children with the onset of a limp or hip/knee pain ( 5.10 )
• Progression of Preexisting Scoliosis: May develop ( 5.11 )
• Pancreatitis: Consider pancreatitis in patients with persistent severe abdominal pain (5.15)

5.1 Acute Critical Illness Increased mortality in patients with acute critical illness due to complications following open heart surgery, abdominal surgery or multiple accidental trauma, or those with acute respiratory failure has been reported after treatment with pharmacologic amounts of somatropin <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span> . Two placebo-controlled clinical trials in non-growth hormone deficient adult patients (n=522) with these conditions in intensive care units revealed a significant increase in mortality (42% vs. 19%) among somatropin-treated patients (doses 5.3-8 mg/day) compared to those receiving placebo. The safety of continuing somatropin treatment in patients receiving replacement doses for approved indications who concurrently develop these illnesses has not been established. Therefore, the potential benefit of treatment continuation with somatropin in patients experiencing acute critical illnesses should be weighed against the potential risk.

5.2 Prader-Willi Syndrome in Children There have been reports of fatalities after initiating therapy with somatropin in pediatric patients with Prader-Willi Syndrome who had one or more of the following risk factors: severe obesity, history of upper airway obstruction or sleep apnea, or unidentified respiratory infection. Male patients with one or more of these factors may be at greater risk than females. Patients with Prader-Willi Syndrome should be evaluated for signs of upper airway obstruction (including onset of or increased snoring) and sleep apnea before initiation of treatment with somatropin. If, during treatment with somatropin, patients show signs of upper airway obstruction (including onset of or increased snoring) and/or new onset sleep apnea, treatment should be interrupted. All patients with Prader-Willi Syndrome treated with somatropin should also have effective weight control and be monitored for signs of respiratory infection, which should be diagnosed as early as possible and treated aggressively <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span> .

5.3 Neoplasms In childhood cancer survivors who were treated with radiation to the brain/head for their first neoplasm and who developed subsequent GHD and were treated with somatropin, an increased risk of a second neoplasm has been reported. Intracranial tumors, in particular meningiomas, were the most common of these second neoplasms. In adults, it is unknown whether there is any relationship between somatropin replacement therapy and CNS tumor recurrence <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span> . Monitor all patients with a history of GHD secondary to an intracranial neoplasm routinely while on somatropin therapy for progression or recurrence of the tumor <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span> . Because children with certain rare genetic causes of short stature have an increased risk of developing malignancies, practitioners should thoroughly consider the risks and benefits of starting somatropin in these patients. If treatment with somatropin is initiated, these patients should be carefully monitored for development of neoplasms. Monitor patients on somatropin therapy carefully for increased growth, or potential malignant changes, of preexisting nevi.

5.4 Impaired Glucose Tolerance and Diabetes Mellitus Treatment with somatropin may decrease insulin sensitivity, particularly at higher doses in susceptible patients. As a result, previously undiagnosed impaired glucose tolerance and overt diabetes mellitus may be unmasked, and new onset type 2 diabetes mellitus has been reported in patients taking somatropin. Therefore, glucose levels should be monitored periodically in all patients treated with somatropin, especially in those with risk factors for diabetes mellitus, such as obesity, Turner Syndrome, or a family history of diabetes mellitus. Patients with preexisting type 1 or type 2 diabetes mellitus or impaired glucose tolerance should be monitored closely during somatropin therapy. The doses of antihyperglycemic drugs (i.e., insulin or oral agents) may require adjustment when somatropin therapy is instituted in these patients <span class="opacity-50 text-xs">[see Drug Interactions ( 7.5 )]</span>.

5.5 Intracranial Hypertension (IH) Intracranial hypertension (IH) with papilledema, visual changes, headache, nausea, and/or vomiting has been reported in a small number of patients treated with somatropins. Symptoms usually occurred within the first eight (8) weeks after the initiation of somatropin therapy. In all reported cases, IH-associated signs and symptoms rapidly resolved after cessation of therapy or a reduction of the somatropin dose. Funduscopic examination should be performed routinely before initiating treatment with somatropin to exclude preexisting papilledema, and periodically during the course of somatropin therapy. If papilledema is observed by fundoscopy during somatropin treatment, treatment should be stopped. If somatropin-induced IH is diagnosed, treatment with somatropin can be restarted at a lower dose after IH-associated signs and symptoms have resolved. Patients with Turner Syndrome and Prader-Willi Syndrome may be at increased risk for the development of IH.

5.6 Hypersensitivity Serious systemic hypersensitivity reactions including anaphylactic reactions and angioedema have been reported with postmarketing use of somatropins. Patients and caregivers should be informed that such reactions are possible and that prompt medical attention should be sought if an allergic reaction occurs <span class="opacity-50 text-xs">[see Contraindications ( 4 )]</span>.

5.7 Fluid Retention Fluid retention during somatropin replacement therapy in adults may frequently occur. Clinical manifestations of fluid retention (e.g. edema, arthralgia, myalgia, nerve compression syndromes including carpal tunnel syndrome/paresthesias) are usually transient and dose dependent.

5.8 Hypoadrenalism Patients receiving somatropin therapy who have or are at risk for pituitary hormone deficiency(s) may be at risk for reduced serum cortisol levels and/or unmasking of central (secondary) hypoadrenalism. In addition, patients treated with glucocorticoid replacement for previously diagnosed hypoadrenalism may require an increase in their maintenance or stress doses following initiation of somatropin treatment <span class="opacity-50 text-xs">[see Drug Interactions ( 7.1 )]</span>.

5.9 Hypothyroidism Undiagnosed/untreated hypothyroidism may prevent an optimal response to somatropin, in particular, the growth response in children. Patients with Turner Syndrome have an inherently increased risk of developing autoimmune thyroid disease and primary hypothyroidism and should have their thyroid function checked prior to initiation of somatropin therapy. In patients with GHD, central (secondary) hypothyroidism may first become evident or worsen during somatropin treatment. Therefore, patients treated with somatropin should have periodic thyroid function tests and thyroid hormone replacement therapy should be initiated or appropriately adjusted when indicated.

5.10 Slipped Capital Femoral Epiphysis in Pediatric Patients Slipped capital femoral epiphysis may occur more frequently in patients with endocrine disorders (including GHD and Turner Syndrome) or in patients undergoing rapid growth. Slipped capital femoral epiphysis may lead to osteonecrosis. Cases of slipped capital femoral epiphysis with or without osteonecrosis have been reported in pediatric patients with short stature receiving somatropin. Any pediatric patient with the onset of a limp or complaints of hip or knee pain during OMNITROPE therapy should be evaluated for slipped capital femoral epiphysis and osteonecrosis and managed accordingly.

5.11 Progression of Preexisting Scoliosis in Pediatric Patients Progression of scoliosis can occur in patients who experience rapid growth. Because somatropin increases growth rate, patients with a history of scoliosis who are treated with somatropin should be monitored for progression of scoliosis. However, somatropin has not been shown to increase the occurrence of scoliosis. Skeletal abnormalities including scoliosis are commonly seen in untreated Turner Syndrome patients. Scoliosis is also commonly seen in untreated patients with Prader-Willi Syndrome. Physicians should be alert to these abnormalities, which may manifest during somatropin therapy .

5.12 Otitis Media and Cardiovascular Disorders in Turner Syndrome Patients with Turner Syndrome should be evaluated carefully for otitis media and other ear disorders since these patients have an increased risk of ear and hearing disorders. Somatropin treatment may increase the occurrence of otitis media in patients with Turner Syndrome. In addition, patients with Turner Syndrome should be monitored closely for cardiovascular disorders (e.g., stroke, aortic aneurysm/dissection, hypertension) as these patients are also at risk for these conditions.

5.13 Lipoatrophy When somatropin is administered subcutaneously at the same site over a long period of time, tissue atrophy may result. This can be avoided by rotating the injection site <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.3 )]</span> .

5.14 Laboratory Tests Serum levels of inorganic phosphorus, alkaline phosphatase, parathyroid hormone (PTH) and IGF-1 may increase after somatropin therapy.

5.15 Pancreatitis Cases of pancreatitis have been reported rarely in children and adults receiving somatropin treatment, with some evidence supporting a greater risk in children compared with adults. Published literature indicates that girls who have Turner Syndrome may be at greater risk than other somatropin-treated children. Pancreatitis should be considered in any somatropin treated patient, especially a child, who develops persistent severe abdominal pain.

5.16 Benzyl Alcohol Benzyl alcohol, a component of OMNITROPE Cartridge 5 mg/1.5 mL and the diluent for OMNITROPE for injection 5.8 mg/vial, has been associated with serious adverse events and death, particularly in pediatric patients. The “gasping syndrome,” (characterized by central nervous system depression, metabolic acidosis, gasping respirations, and high levels of benzyl alcohol and its metabolites found in the blood and urine) has been associated with benzyl alcohol dosages &gt;99 mg/kg/day in neonates and low-birth weight neonates. Additional symptoms may include gradual neurological deterioration, seizures, intracranial hemorrhage, hematologic abnormalities, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse. Practitioners administering this and other medications containing benzyl alcohol should consider the combined daily metabolic load of benzyl alcohol from all sources.