Mecasermin side effects and risks

Reported side effects

• Low blood sugar: FDA pool: 30/71, 42%; 5 had severe episodes and 4 had seizures or loss of consciousness., serious. Link doses to food and monitor glucose. Lower the dose if episodes occur despite adequate food. (source)
• Tonsil or adenoid growth: FDA pool: tonsillar growth in 11/71, 15%; 7 required surgery., moderate. Assess new snoring, sleep pauses, swallowing problems or ear symptoms. (source)
• Injection-site fat growth: 32% in the separate 76 patient long term cohort; not the FDA 71 patient pool., mild. Rotate injection sites. (source)
• Headache or vomiting: Each reported in ≥5% in the FDA pool; exact separate rates are not given there., moderate. Persistent severe headache, vomiting or visual changes need urgent assessment. (source)
• Raised pressure around the brain: FDA pool: 3/71 had intracranial hypertension., serious. Eye examination at baseline and periodically; assess new headaches or vision changes. (source)
• Severe allergic reaction: Postmarketing anaphylaxis estimate 0.3%; voluntary reports have uncertain denominators., serious. Stop and seek emergency care for breathing trouble or facial swelling. (source)
• Joint pain, bruising or ear problems: Individual listed reactions occurred in ≥5% in the FDA pool; precise rates not supplied., moderate (source)
• Edema and jaw pain: Higher dose type 1 diabetes arms had unacceptable rates; exact rates not extracted., moderate (source)
• Worsening diabetic eye disease: 11/55 in a younger type 1 diabetes subset; this does not estimate risk in all users., serious (source)
• Benign or malignant growths: Postmarketing cases reported. Causation and a reliable cancer incidence are unknown., serious. New lumps, changing moles or other growths need prompt medical review. (source)
• Hip growth-plate slip or bone tissue death: Reported in children; frequency unknown., serious. New limp or hip/knee pain needs prompt evaluation. (source)
• Benzyl-alcohol toxicity in neonates and infants: The label warns of serious and fatal reactions with benzyl alcohol preserved drugs; this is not an incidence estimate for Increlex., serious. Increlex contains 9 mg/mL benzyl alcohol. Its label does not recommend use in infants; safety and effectiveness below age 2 are not established. (source)

Stop and get help if

• Confusion, seizure, fainting or persistent low blood sugar: Stop dosing and get emergency care. Do not give food or drink to an unconscious person.
• Breathing trouble, throat/facial swelling or widespread hives: Stop dosing and get emergency care.
• Severe or persistent headache, vomiting or new vision changes: Stop dosing and seek urgent evaluation for raised pressure around the brain.
• New limp or hip/knee pain: Get prompt care for hip growth-plate slip or bone tissue death.
• Chest pain, collapse or severe breathlessness: Get emergency care now.
• New or changing lump, mole or other abnormal growth: Stop dosing and arrange prompt specialist assessment.

Who should avoid it

• under18: Increlex itself is approved from age 2; this app block is not an FDA pediatric contraindication.
• pregnant: No adequate human pregnancy data. The EU label says not to use during pregnancy.
• breastfeeding: Milk transfer and infant effects are unknown.
• tryingToConceive: This is a precaution. The EU label advises pregnancy testing and contraception during treatment.
• activeCancer: Active or suspected neoplasia is a stop condition. Discontinue if a tumor develops.
• cancerHistory: The US label excludes pediatric patients with prior malignancy; EU/UK restrictions include cancer-predisposing history.
• other: Do not re-expose after a serious reaction to mecasermin or an ingredient.
• other: Do not use for height gain after growth plates close. Adult bones cannot lengthen through this mechanism.
• other: Food must be available around each dose. Withhold a dose when the meal or snack is omitted.
• diabetes: Glucose-lowering treatment may need adjustment; low blood sugar can be severe.
• diabeticRetinopathy: One IGF-1/insulin trial reported early retinal worsening at higher doses.
• seizureDisorder: Hypoglycemia can cause seizures or loss of consciousness.
• sleepApnea: Tonsil/adenoid enlargement may worsen snoring or obstructed breathing.
• heartCondition: Fluid retention and cardiac changes warrant review; cardiac causation in growth studies was uncertain.
• kidneyDisease: No established dose adjustment for children with primary IGF-1 deficiency and kidney disease.
• liverDisease: No established dose adjustment for children with primary IGF-1 deficiency and liver disease.
• surgeryPlanned: Fasting may require withheld doses and adjusted glucose-lowering treatment.
• other: Raised brain pressure is a risk; eye checks are recommended before and during treatment.
• other: Rapid growth can worsen an existing spinal curve.
• testedAthlete: WADA prohibits mecasermin at all times under S2.3.

Interactions

• Insulin: Doses may need reduction because of additive low blood sugar. Insulin co-treatment in trials required close glucose checks.
• Sulfonylureas and other insulin releasers: Other glucose-lowering medicines may need reduction. No formal interaction study defines a dose change.
• Other IGF-1 products: No safe schedule is established for combining IGF-1 products.
• Growth hormone and secretagogues: Pediatric GH combinations were studied in selected patients; this does not establish a safe adult or secretagogue stack.
• Anticoagulants and antiplatelets: No interaction studies are available. Injection-site bruising and bleeding have been reported.

Product quality risks

• Unregulated IGF-1 analogues are not interchangeable with licensed mecasermin. A tested LR3 vial contained an extra purification tag.
• No current market-wide survey of counterfeit or underdosed Increlex was located. Specific counterfeit-pen rates are unknown.
• A research-use-only label or purity percentage does not establish identity, amount, sterility or freedom from endotoxin.