Approved indications
• Strensiq is approved for long-term enzyme replacement therapy in patients with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP), a rare genetic disorder of bone mineralization.

Off-label uses
• Clinically meaningful use is essentially limited to HPP; there are no well-established or routine off-label indications, and evidence for use in other bone or metabolic diseases is minimal and experimental.

Efficacy expectations
• In infants and young children with life-threatening HPP, improvements in respiratory status, bone mineralization on X-ray, and survival can appear over weeks to months, with continued gains over years.
• Patients often show better growth, reduced fractures, improved motor function, and decreased need for respiratory support compared with historical outcomes without treatment.
• Compared with prior management (supportive care only), Strensiq has transformed prognosis in severe pediatric HPP, with substantially higher survival and improved skeletal outcomes; there are no alternative enzyme replacement therapies specifically approved for HPP.

Typical dosing and how to take
• The usual recommended dose is 6 mg/kg per week given by subcutaneous injection, either as 2 mg/kg three times weekly or 1 mg/kg six times weekly.
• In some patients with more severe disease or inadequate response, doses up to 9 mg/kg per week may be used according to prescribing information and specialist judgment.
• Injections are given under the skin in areas such as the abdomen, thigh, or upper arm, and injection sites should be rotated; a healthcare provider trains caregivers or patients in proper technique.
• Strensiq is not taken by mouth and is not mixed with other medicines; it does not need to be taken with food, but dosing times should be kept as consistent as possible.

Special dosing instructions
• Dose is based on actual body weight and should be adjusted as the patient grows or weight changes.
• Multiple injections may be required for higher doses because there is a maximum volume per injection; the total calculated weekly dose is divided accordingly.
• Inspect the solution before use and do not use if cloudy, discolored, or containing particles.

Missed dose guidance
• If a dose is missed, it is generally taken as soon as remembered on that same day, and the regular schedule is resumed; doses should not be doubled to make up for a missed injection.
• Patients should contact their HPP specialist for specific advice if multiple doses are missed.

Overdose
• There is limited experience with overdose; potential effects could include more pronounced side effects such as injection reactions or abnormal calcium or phosphate balance.
• In case of suspected overdose, patients should seek medical evaluation promptly; treatment is usually supportive, with monitoring of clinical status and relevant laboratory values.

Common side effects
• Very common reactions include injection site reactions (redness, pain, itching, swelling, discoloration, lumps), which are usually mild to moderate and often appear early in therapy.
• Other frequent effects include lipodystrophy (loss or buildup of fat) at injection sites over time, headache, pyrexia (fever), irritability in infants, vomiting, and upper respiratory infections; most are mild to moderate.

Serious or rare adverse effects
• Serious hypersensitivity reactions, including anaphylaxis, can occur and may present with difficulty breathing, swelling of face or throat, hives, or severe hypotension; treatment should be stopped and emergency care sought immediately.
• Some patients develop ectopic calcifications (such as in the eyes or kidneys), so periodic eye exams and monitoring for renal complications may be recommended.
• Injection site lipodystrophy can be persistent; rotating injection sites reduces risk.

Warnings and precautions
• Use in pregnancy and breastfeeding: human data are limited; the drug is generally used when the potential benefit to the mother or fetus/infant outweighs potential risks, under specialist guidance.
• No specific dose adjustment guidance exists for kidney or liver impairment, but these conditions warrant careful monitoring.
• The drug is approved for patients of all ages with perinatal/infantile- or juvenile-onset HPP; its use should be supervised by clinicians experienced in managing this rare disease.

Safety compared with other options
• Before Strensiq, treatment of HPP was mainly supportive; compared with no enzyme replacement, Strensiq introduces risks of injection-related and immune-mediated effects but offers major survival and functional benefits in appropriate patients.

Side effect reporting and safety updates
• Patients and caregivers can report suspected side effects to the FDA MedWatch program or to the manufacturer’s safety line, and clinicians should check current product labeling or regulatory websites for updated safety communications.

Drug and other interactions
• No major drug–drug interactions have been identified for Strensiq, and it is not known to significantly affect common liver enzyme pathways used by many medicines.
• There are no specific known interactions with foods or alcohol, but alcohol should be used cautiously in patients with bone or liver disease in general.
• Because Strensiq can alter bone mineralization and alkaline phosphatase–related laboratory tests, clinicians should interpret some lab and imaging findings (for example, bone scans) in the context of ongoing therapy.

Precautions and conditions needing caution
• History of serious hypersensitivity or anaphylaxis to asfotase alfa or its excipients is a contraindication to further use.
• Patients with pre-existing eye disease, kidney disease, or known ectopic calcifications should be monitored closely, since the drug can be associated with additional calcifications.
• Immunogenicity (development of anti-drug antibodies) may occur and in some cases can reduce effectiveness or increase the risk of reactions; clinicians may monitor for loss of response or unusual side effects.

Monitoring needs
• Regular follow-up typically includes growth and developmental assessments, bone imaging, respiratory status (especially in infants), and laboratory tests (such as calcium, phosphate, and vitamin D status).
• Eye examinations and evaluation for nephrocalcinosis (for example, with renal ultrasound) may be recommended to detect ectopic calcifications.
• Routine vital signs and clinical assessment at visits help detect hypersensitivity or other emerging safety concerns.

Q: What is Strensiq used for?
A: Strensiq is an enzyme replacement medicine used to treat people with perinatal/infantile- or juvenile-onset hypophosphatasia (HPP), a rare genetic condition that weakens bones and can affect breathing, growth, and mobility.

Q: How long does it take for Strensiq to work?
A: Some infants and children show early improvements in breathing and bone changes within weeks to a few months, but full benefits on growth, strength, and function usually build gradually over many months to years of continuous treatment.

Q: How is Strensiq given at home?
A: After training by a healthcare professional, caregivers or patients give Strensiq as subcutaneous injections several times per week, rotating injection sites and following instructions on dose preparation, injection technique, and sharps disposal.

Q: What are the most common side effects of Strensiq?
A: The most common side effects are injection site reactions such as redness, pain, swelling, itching, or lumps, along with lipodystrophy at injection sites, fever, headache, vomiting, and respiratory infections, most of which are mild to moderate.

Q: Do patients need to stay on Strensiq for life?
A: Because hypophosphatasia is a lifelong genetic condition and Strensiq replaces a missing enzyme rather than curing the disease, many patients require long-term or potentially lifelong therapy, with ongoing reassessment of benefits and risks by their specialist.

Storage
• Store Strensiq refrigerated at 36°F to 46°F (2°C to 8°C); do not freeze.
• Keep in the original carton to protect from light and do not shake the vials or prefilled syringes.
• If needed, the product may generally be kept at room temperature for a limited time as specified in the package labeling, after which it must not be returned to the refrigerator.

Handling and disposal
• Use only clear, particle-free solution and discard any unused portion of a vial or prefilled syringe after a dose (single-use).
• Dispose of used needles, syringes, and vials immediately in an FDA-cleared sharps container; follow local or pharmacy guidance for disposal when the container is full.
• Keep all supplies out of reach of children and pets.